ALBERT

Description: Micro-Raman spectroscopy has been used on adult bivalve shells to investigate organic and inorganic shell components but has not yet been applied to bivalve larvae. It is known that the organic matrix of larval shells contains pigments, but less is known about the presence or source of these molecules in larvae. We investigated Raman spectra of seven species of bivalve larvae to assess the types of pigments present in shells of each species and how the ratio of inorganic : organic material changes in a dorso-ventral direction. In laboratory experiments, we reared larvae of three clam species in waters containing different organic signatures to determine if larvae incorporated compounds from source waters into their shells. We found differences in spectra and pigments between most species but found less intraspecific differences. A neural network classifier for Raman spectra classified five out of seven species with greater than 85% accuracy. There were slight differences between the amount and type of pigment present along the shell, with the prodissoconch I and shell margin areas being the most variable. Raman spectra of 1-day-old larvae were found to be differentiable when larvae were reared in waters with different organic signatures. With micro-Raman spectroscopy, it may be possible to identify some unknown species in the wild and trace their natal origins, which could enhance identification accuracy of bivalve larvae and ultimately aid management and restoration efforts.

Description: INTRODUCTION: Lichens are self-sustaining partnerships comprising fungi as shape-forming partners for their enclosed symbiotic algae. They produce a tremendous diversity of metabolites (1050 metabolites described so far). OBJECTIVES: A comparison of metabolic profiles in nine lichen species belonging to three genera (Lichina, Collema and Roccella) by using an optimised extraction protocol, determination of the fragmentation pathway and the in situ localisation for major compounds in Roccella species. METHODS: Chemical analysis was performed using a complementary study combining a Taguchi experimental design with qualitative analysis by high-performance liquid chromatography coupled with mass spectrometry techniques. RESULTS: Optimal conditions to obtain the best total extraction yield were determined as follows: mortar grinding to a fine powder, two successive extractions, solid:liquid ratio (2:60) and 700 rpm stirring. Qualitative analysis of the metabolite profiling of these nine species extracted with the optimised method was corroborated using MS and MS/MS approaches. Nine main compounds were identified: 1 β-orcinol, 2 orsellinic acid, 3 putative choline sulphate, 4 roccellic acid, 5 montagnetol, 6 lecanoric acid, 7 erythrin, 8 lepraric acid and 9 acetylportentol, and several other compounds were reported. Identification was performed using the m/z ratio, fragmentation pathway and/or after isolation by NMR analysis. The variation of the metabolite profile in differently organised parts of two Roccella species suggests a specific role of major compounds in developmental stages of this symbiotic association. CONCLUSION: Metabolic profiles represent specific chemical species and depend on the extraction conditions, the kind of the photobiont partner and the in situ localisation of major compounds.

Description: Brackish coastal groundwater is enriched in Ra, which is transported to surface waters via submarine groundwater discharge (SGD). The Ra activity of the SGD end-member is influenced by a variety of environmental factors including salinity, pH, and isotope half-life. In the York River estuary (YRE), 223Ra, 224Ra, and 226Ra were measured in surface water and shallow groundwater across a range of salinities and additional Ra sources quantified (desorption and diffusion from sediments, input from tidal marshes). The Ra budget of the estuary indicated a major source of Ra that could only be satisfied by SGD. The apparent Ra flux was combined with groundwater Ra end-member activity to estimate SGD volume fluxes of 5–178 L m− 2 d− 1. Each isotope exhibited a different seasonal pattern, with significantly higher 224Ra flux during summer than winter, lower 226Ra SGD flux during summer than winter, and no seasonal differences in 223Ra SGD flux. However, the SGD 224Ra end-member activity varied with seasonal pore water salinity fluctuations, indicating end-member control on seasonal 224Ra flux. Each Ra isotope suggested a different SGD volume flux, indicating that different nuclide regeneration rates may respond to and reflect different flow mechanisms in the subterranean estuary. This work indicates that volume fluxes estimated using geochemical tracers are sensitive to SGD end-member variations and end-member variability must be well-characterized for reliable SGD flux estimates.

Description: In this paper we present an in-depth analysis and synthesis of published and newly acquired data on the chemical and isotopic composition of forearc fluids, fluid fluxes, and the associated thermal regimes in well-studied, representative erosional and accretionary subduction zone (SZ) forearcs. Evidence of large-scale fluid flow, primarily focused along faults, is manifested by widespread seafloor venting, associated biological communities, extensive authigenic carbonate formation, chemical and isotopic anomalies in pore-fluid depth-profiles, and thermal anomalies. The nature of fluid venting seems to differ at the two types of SZs. At both, fluid and gas venting sites are primarily associated with faults. The décollement and coarser-grained stratigraphic horizons are the main fluid conduits at accretionary SZs, whereas at non-accreting and erosive margins, the fluids from compaction and dehydration reactions are to a great extent partitioned between the décollement and focused conduits through the prism, respectively. The measured fluid output fluxes at seeps are high, ∼15–40 times the amount that can be produced through local steady-state compaction, suggesting that in addition, other fluid sources or non-steady-state fluid flow must be involved. Recirculation of seawater must be an important component of the overall forearc output fluid flux in SZs. The most significant chemical and isotopic characteristics of the expelled fluids relative to seawater are: Cl dilution; sulfate, Ca, and Mg depletions; and enrichments in Li, B, Si, Sr, alkalinity, and hydrocarbon concentrations, often distinctive δ18O, δD, δ7Li, δ11B, and δ37Cl values, and variable Sr isotope ratios. These characteristics provide key insights on the source of the fluid and the temperature at the source. Based on the fluid chemistry, the most often reported source temperatures reported are 120–150 °C. We estimate a residence time of the global ocean in SZs of ∼100 Myr, about five times faster than the previous estimate of ∼500 Myr by Moore and Vrolijk, similar to the residence time of ∼90 Myr for fluids in the global ridge crest estimated by Elderfield and Schultz, and ∼3 times longer than the 20–36 Myr estimate by German and von Damm and Mottl. Based on this extrapolated fluid reflux to the global ocean, subduction zones are an important source and sink for several elements and isotopic ratios, in particular an important sink for seawater sulfate, Ca and Mg, and an important source of Li and B.

Description: Uncertainty over the identity and age of Toba tephras across peninsular India persists, with radiometric age dates contradicting earlier compositional data, which have been used to identify this important Stratigraphie marker as the Youngest Toba Tuff (YTT). To address this issue, new single glass shard analyses have been performed for samples from Morgaon and Bori (north-western India), which have recently been dated at c. 800 ka. These, and indeed all Toba tephra samples thus far analysed from India, show the presence of four populations of glass shards (defined by their Ba/Y ratio), which uniquely identifies them as products of the c. 75-ka Youngest Toba eruption. Confirmation that the YTT fingerprint is characteristic comes from new analyses of Oldest Toba Tuff (OTT) glass shards from five sites in the Indian Ocean. These are compositionally identical to Layer D from the ODP site 758 Sediment core (c. 800 ka), and belong to a single, low-Ba population, clearly different from YTT. These analyses show that there is essentially no reworked OTT material in the YTT eruption, and indicate unequivocally that all known Toba tephra occurrences in India belong to the c. 75-ka Youngest Toba eruption.

Description: A very close coupling exists between changes in atmospheric O2 and CO2 concentrations, owing to the chemistry of photosynthesis, respiration, and combustion. The coupling is not perfect, however, because CO2 variations are partially buffered by reactions involving the inorganic carbon system in seawater, which has no effect on O2. Measurements over the past two decades document variations in O2 on a range of space and time scales, including a long-term decrease driven mostly by fossil fuel burning and seasonal cycles driven by exchanges with the land biosphere and the oceans. In this chapter, these and other features seen in the measurements are described, also discussing variations in the tracer ‘atmospheric potential oxygen,’ which is a linear combination of O2 and CO2 designed to be insensitive to exchanges from the land biosphere and thereby sensitive mostly to oceanic processes. Challenges associated with measuring variations in O2 are addressed, and various applications of the observations are discussed, including quantifying the magnitude of the global land and ocean carbon sinks and testing ocean biogeochemical models. An updated budget for global carbon sinks based on O2 measurements from the Scripps O2 program is presented for the decades of the 1990s and 2000s.

Description: Marine laminated sediments in dysoxic areas of the ocean floor are an excellent archive for high-resolution climate reconstructions. While the existence of discontinuities produced by natural events, such as underwater landslides (slumps), strong bottom currents, and/or bioturbation is usually acknowledged for long records, the extent of their influence on high-resolution sequences is usually not considered. In the present work we show strong evidence for multiple stratigraphic discontinuities in different gravity and box-cores retrieved off Pisco (Peru) covering the last 600 years. Chronostratigraphies are largely based on cross-correlation of distinct sedimentary structures (determined by X-ray image analysis) and validated using 210Pb, 241Am, and 14C profiles, as well as proxy records. The cross-correlation of distinct stratigraphic layers allows for chronostratigraphic tie points and clearly shows that some sedimentary sequences are continuous across scales of tens of kilometers, indicating that regional processes often determine laminae formation. Some differences in laminae thickness were found among cores, which could be explained by different sedimentation rates, spatially variable deposition of diatom blooms, changes in silica dissolution and partial deposition/erosion caused by bottom currents. Using multiple stratigraphic tie points provides clear evidence for laminated sequences present in some cores to be missing in other cores. Moreover, instantaneous depositions from upslope were identified in all the cores disrupting the continuity of the sediment records. These discontinuities (instantaneous deposits and missing sequences) may be due to slumps, possibly triggered by earthquakes and/or erosion by strong bottom currents. In spite of the missing sequences in some cores, a continuous composite record of the last six centuries was reconstructed from spliced sequences of the different cores, which provides a well-constrained temporal framework to develop further high-resolution proxies in this region. The present work shows that paleoreconstructions developed from single cores, particularly in areas with strong seismic activity and/or strong bottom currents, are subject to both temporal gaps and instantaneous depositions from upslope, both of which could be misinterpreted as abrupt climate changes or anomalous climate events. We stress the need for multiple cores to determine the stratigraphic continuity and chronologies for high-resolution records.

Description: Forazoline A, a novel antifungal polyketide with in vivo efficacy against Candida albicans, was discovered using LCMS-based metabolomics to investigate marine-invertebrate-associated bacteria. Forazoline A had a highly unusual and unprecedented skeleton. Acquisition of 13C–13C gCOSY and 13C–15N HMQC NMR data provided the direct carbon–carbon and carbon–nitrogen connectivity, respectively. This approach represents the first example of determining direct 13C–15N connectivity for a natural product. Using yeast chemical genomics, we propose that forazoline A operated through a new mechanism of action with a phenotypic outcome of disrupting membrane integrity.

Description: Kelp forests represent a major habitat type in coastal waters worldwide and their structure and distribution is predicted to change due to global warming. Despite their ecological and economical importance, there is still a lack of reliable spatial information on their abundance and distribution. In recent years, various hydroacoustic mapping techniques for sublittoral environments evolved. However, in turbid coastal waters, such as off the island of Helgoland (Germany, North Sea), the kelp vegetation is present in shallow water depths normally excluded from hydroacoustic surveys. In this study, single beam survey data consisting of the two seafloor parameters roughness and hardness were obtained with RoxAnn from water depth between 2 and 18 m. Our primary aim was to reliably detect the kelp forest habitat with different densities and distinguish it from other vegetated zones. Five habitat classes were identified using underwater-video and were applied for classification of acoustic signatures. Subsequently, spatial prediction maps were produced via two classification approaches: Linear discriminant analysis (LDA) and manual classification routine (MC). LDA was able to distinguish dense kelp forest from other habitats (i.e. mixed seaweed vegetation, sand, and barren bedrock), but no variances in kelp density. In contrast, MC also provided information on medium dense kelp distribution which is characterized by intermediate roughness and hardness values evoked by reduced kelp abundances. The prediction maps reach accordance levels of 62% (LDA) and 68% (MC). The presence of vegetation (kelp and mixed seaweed vegetation) was determined with higher prediction abilities of 75% (LDA) and 76% (MC). Since the different habitat classes reveal acoustic signatures that strongly overlap, the manual classification method was more appropriate for separating different kelp forest densities and low-lying vegetation. It became evident that the occurrence of kelp in this area is not simply linked to water depth. Moreover, this study shows that the two seafloor parameters collected with RoxAnn are suitable indicators for the discrimination of different densely vegetated seafloor habitats in shallow environments.

Description: Eutrophication, coupled with loss of herbivory due to habitat degradation and overharvesting, has increased the frequency and severity of macroalgal blooms worldwide. Macroalgal blooms interfere with human activities in coastal areas, and sometimes necessitate costly algal removal programmes. They also have many detrimental effects on marine and estuarine ecosystems, including induction of hypoxia, release of toxic hydrogen sulphide into the sediments and atmosphere, and the loss of ecologically and economically important species. However, macroalgal blooms can also increase habitat complexity, provide organisms with food and shelter, and reduce other problems associated with eutrophication. These contrasting effects make their overall ecological impacts unclear. We conducted a systematic review and meta-analysis to estimate the overall effects of macroalgal blooms on several key measures of ecosystem structure and functioning in marine ecosystems. We also evaluated some of the ecological and methodological factors that might explain the highly variable effects observed in different studies. Averaged across all studies, macroalgal blooms had negative effects on the abundance and species richness of marine organisms, but blooms by different algal taxa had different consequences, ranging from strong negative to strong positive effects. Blooms' effects on species richness also depended on the habitat where they occurred, with the strongest negative effects seen in sandy or muddy subtidal habitats and in the rocky intertidal. Invertebrate communities also appeared to be particularly sensitive to blooms, suffering reductions in their abundance, species richness, and diversity. The total net primary productivity, gross primary productivity, and respiration of benthic ecosystems were higher during macroalgal blooms, but blooms had negative effects on the productivity and respiration of other organisms. These results suggest that, in addition to their direct social and economic costs, macroalgal blooms have ecological effects that may alter their capacity to deliver important ecosystem services.

Description: The convergence between the Indian plate and the southern margin of the Eurasian continent created an active continental margin from Late Jurassic until about 40 Ma ago, which then evolved to form the Himalaya and the Tibetan Plateau during the continental collision stage. Post-collisional magmatism in southern Tibet, north of the Yarlung Zangbo Suture Zone (YZSZ) has been active since 45 Ma and is related to normal faulting and extensional tectonism. To date no such magmatism was reported within the YZSZ itself. This paper reports on the discovery of Miocene shoshonites within the YZSZ. They are significant because the magma traveled, at least in part, through oceanic crust, thus limiting interaction with the continental crust to the mid-crustal level and which affected the post-collisional magmatic rocks occurring in the northern part of the subduction system. In addition, xenoliths and xenocrysts of crustal origin in these rocks constrain the nature of metamorphic rocks underlying the YZSZ at mid-crustal level. The geochemical signatures of the shoshonitic rocks, including Nd and Sr isotope systematics, indicate derivation from a garnet-bearing middle continental crustal source. Crustal imprint complicates modeling of the petrogenetic processes which occurred prior to mid-crustal ponding of the magma which took place between 11 and 17 Ma at depths of 40 to 50 km. The significant role of crustal contamination raises serious concerns about models proposed for similar magmatic activity elsewhere in the Himalaya and the Tibetan Plateau.

Description: Arc magmas are commonly assumed to form by melting of sub-arc mantle that has been variably enriched by a component from the subducted slab. Although most magmas that reach the surface are not primitive, the impact of assimilation of the arc crust is often ignored with the consequence that trace element and isotopic compositions are commonly attributed only to varying contributions from different components present in the mantle. This jeopardises the integrity of mass balance recycling calculations. Here we use Sr and O isotope data in minerals from a suite of volcanic rocks from St Lucia, Lesser Antilles arc, to show that assimilation of oceanic arc basement can be significant. Analysis of 87Sr/86Sr in single plagioclase phenocrysts from four Soufrière Volcanic Complex (SVC; St Lucia) hand samples with similar composition (87Sr/86Sr = 0.7089–0.7091) reveals crystal isotopic heterogeneity among hand samples ranging from 0.7083 to 0.7094 with up to 0.0008 difference within a single hand sample. measurements in the SVC crystals show extreme variation beyond the mantle range with +7.5 to ‰ for plagioclase (), +10.6 to ‰ for quartz (), +9.4 to ‰ for amphibole () and +9 to ‰ for pyroxene () while older lavas (Pre-Soufriere Volcanic Complex), with less radiogenic whole rock Sr composition (87Sr/86Sr = 0.7041–0.7062) display values closer to mantle range: +6.4 to ‰ for plagioclase () and +6 to ‰ for pyroxene (). We argue that the 87Sr/86Sr isotope disequilibrium and extreme values provide compelling evidence for assimilation of material located within the arc crust. Positive correlations between mineral and whole rock 87Sr/86Sr, 143Nd/144Nd and 206,207,208Pb/204Pb shows that assimilation seems to be responsible not only for the isotopic heterogeneity observed in St Lucia but also in the whole Lesser Antilles since St Lucia encompasses almost the whole-arc range of isotopic compositions. This highlights the need for detailed mineral-scale investigation of oceanic arc suites to quantify assimilation that could otherwise lead to misinterpretation of source composition and subduction processes.

Description: The scleractinian cold-water corals (CWC) Lophelia pertusa and Madrepora oculata represent two major deep-sea reef-forming species that act as key ecosystem engineers over a wide temperature range, extending from the northern Atlantic (ca. 5–9 °C) to the Mediterranean Sea (ca. 11–13 °C). Recent research suggests that environmental parameters, such as food supply, settling substrate availability or aragonite saturation state may represent important precursors controlling habitat suitability for CWC. However, the effect of one principal environmental factor, temperature, on CWC key physiological processes is still unknown. In order to evaluate this effect on calcification, respiration, and dissolved organic carbon (DOC) net flux, colonies of Mediterranean L. pertusa and M. oculata were acclimated in aquaria to three temperatures (12, 9 and 6 °C), by consecutive decrements of 1 month duration. L. pertusa and M. oculata maintained at Mediterranean control conditions (i.e. 12 °C) displayed constant rates, on average respiring 4.8 and 4.0 µmol O2 cm−2 coral surface area d−1, calcifying 22.3 and 12.3 µmol CaCO3 g−1 skeletal dry weight d−1 and net releasing 2.6 and 3.1 µmol DOC cm−2 coral surface area d−1, respectively. Respiration of L. pertusa was not affected by lowered temperatures, while M. oculata respiration declined significantly (by 48%) when temperature decreased to 9 °C and 6 °C relative to controls. L. pertusa calcification at 9 °C was similar to controls, but decreased significantly (by 58%) at 6 °C. For M. oculata, calcification declined by 41% at 9 °C and by 69% at 6 °C. DOC net flux was similar throughout the experiment for both CWC. These findings reveal species-specific physiological responses by CWC within their natural temperature range. L. pertusa shows thermal acclimation in respiration and calcification, while these mechanisms appear largely absent in M. oculata. Conclusively, species-specific thermal acclimation may significantly affect the occurrence and local abundance of cosmopolitan CWC species, consequently influencing their important role in habitat engineering and ecosystem functioning in various thermal environments. Keywords

Description: Dissolved organic matter, which contains many compounds such as lipids, sugars and amino acids, is an important source of carbon and nitrogen for several symbiotic and asymbiotic tropical coral species. However, there is still no information on its possible uptake by cold-water coral species. In this study, we demonstrated that dissolved organic matter, in the form of dissolved free amino acids (DFAA), is actively absorbed by four cold-water coral species from the Mediterranean Sea. Although the uptake rates observed with 3 µM DFAA concentration were one order of magnitude lower than those observed in tropical species, they corresponded to 12–50% of the daily excreted-nitrogen, and 16–89% of the daily respired-carbon of the cold-water corals. Consequently, DFAA, even at in situ concentrations lower than those tested in this study, can supply a significant amount of carbon and nitrogen to the corals, especially during periods when particulate food is scarce.

Description: Redox-sensitive trace metals (Mn, Fe, U, Mo, Re), nutrients and terminal metabolic products (NO3-, NH4+, PO43-, total alkalinity) were investigated for the first time in pore waters of Antarctic coastal sediments. The results of this study reveal a high spatial variability in redox conditions in surface sediments from Potter Cove, King George Island, western Antarctic Peninsula. Particularly in the shallower areas of the bay the significant correlation between sulphate depletion and total alkalinity, the inorganic product of terminal metabolism, indicates sulphate reduction to be the major pathway of organic matter mineralisation. In contrast, dissimilatory metal oxide reduction seems to be prevailing in the newly ice-free areas and the deeper troughs, where concentrations of dissolved iron of up to 700 μM were found. We suggest a combination of several factors to be responsible for the domination of metal oxide reduction over sulphate reduction in these areas. These include the increased accumulation of fine-grained material with high amounts of reducible metal oxides, a reduced availability of metabolisable organic matter and an enhanced physical and biological disturbance by bottom water currents, ice scouring and burrowing organisms. Based on modelled iron fluxes we calculate the contribution of the Antarctic shelf to the pool of potentially bioavailable iron (Feb) to be 6.9 × 103 to 790 × 103 t yr-1. Consequently, these shelf sediments would provide an Feb flux of 0.35-39.5 mg m-2 yr-1 (median: 3.8 mg m-2 yr-1) to the Southern Ocean. This contribution is in the same order of magnitude as the flux provided by icebergs and significantly higher than the input by aeolian dust. For this reason suboxic shelf sediments form a key source of iron for the high nutrient-low chlorophyll (HNLC) areas of the Southern Ocean. This source may become even more important in the future due to rising temperatures at the WAP accompanied by enhanced glacier retreat and the accumulation of melt water derived iron-rich material on the shelf.

Description: Compared with microscopic indices such as biomass, inverted satellite images can reflect cyanobacterial blooms from a macroscopic perspective, can provide planar information for blooms, and can more definitely reflect the occurrence of visible cyanobacterial blooms. We therefore adopted inverted images (from MODIS imagery) to judge whether cyanobacterial blooms had occurred in a water area at a given time. We constructed two probit models for identifying significant environmental factors related to cyanobacterial bloom occurrence and for short-term forecasts of bloom occurrence. The models used the index of cyanobacterial bloom occurrence as the dependent variable and the predicted variable, respectively, and used three categories (water quality, hydrology, and weather) of monitoring variables as the independent variables (or predictive variables). We used the Hill Dagong water area of Lake Tai in China as a case study of the new methods. The results produced by the identification model are consistent with the general conclusions in this research field indicating the validity of the model. The mean relative error of the forecast model is 13.5%, which is close to or lower than that of two previous models. Compared with the previous models, our forecast model also has advantages in terms of spatial and temporal precision. The new models have both practical applicability and the ability to be generalized and can, therefore, be easily adapted for the prevention, control, and prediction of cyanobacterial blooms in other bodies of water.

Description: Fresh volcanic glasses from the extrusive section of the Troodos Ophiolite in Akaki Canyon are tholeiitic and basaltic to dacitic in composition. Compared to normal MORB they have extremely low fractionation corrected Na8, Fe8 and Ti8 and are enriched in fluid-mobile trace elements, including U, Ba, Rb, Sr and Pb, relative to non-fluid mobile elements of similar incompatibility. Trace element compositions of Akaki lavas define an array extending between ‘back-arc lava’-like compositions, and the field defined by Troodos boninites from the upper part of the lava sequence. Troodos lavas were derived from a mantle source that underwent early melt depletion, and later enrichment by both fluids and small degree melts. These processes can explain the unusual negative correlation of Pb/Ce with Zr/Nb and Ba/Nb in Troodos extrusives. Although some Troodos lavas are similar in composition to lavas from back-arc spreading centres, the boninites from the upper parts of the lava pile do not appear to have exact compositional equivalents among lavas from fore-arcs, back-arcs or other tectonic settings where similar rocktypes have been recovered. We suggest that the geochemical evolution inferred for the mantle source of Troodos lavas, together with geological evidence is most consistent with an origin for the Troodos Ophiolite at a spreading centre close to a ridge–trench–trench, or ridge–trench–transform triple junction, where highly depleted, subduction-modified, fluid-enriched mantle wedge material was able to upwell and decompress to shallow depths in a ‘fore-arc’ location. In such a tectonic setting, arc volcanism is captured by the spreading centre, explaining the lack of evidence for subaerial arc magmatism in Troodos. Rapid lateral migration of the triple junction could account for the similar ages of other Tethyan supra-subduction zone ophiolites.

Description: In virtually every assessment of responses to large-scale crises and disasters, coordination is identified as a critical failure factor. After the crisis, official committees and political opponents often characterize the early phases of the response as a ‘failure to coordinate.’ Not surprisingly, improved coordination quickly emerges as the prescribed solution. Coordination, then, is apparently both the problem and the solution. But the proposed solutions rarely solve the problem: coordination continues to mar most crises and disasters. In the absence of a shared body of knowledge on coordination, it is hard to formulate a normative framework that allows for systematic assessment of coordination in times of crisis. As coordination is widely perceived as an important function of crisis and disaster management, this absence undermines a fair and balanced assessment of crisis management performance. This paper seeks to address that void. We aim to develop a framework that explains both the failure and success of crisis coordination. We do this by exploring the relevant literature, reformulating what coordination is and distilling from research the factors that cause failure and success.

Description: The purine alkaloid caffeine is a major component of many beverages such as coffee and tea. Caffeine and its metabolites theobromine and xanthine have been shown to have antioxidant properties. Caffeine can also act as adenosine-receptor antagonist. Although it has been shown that adenosine and antioxidants promote wound healing, the effect of caffeine on wound healing is currently unknown. To investigate the effects of caffeine on processes involved in epithelialisation, we used primary human keratinocytes, HaCaT cell line and ex vivo model of human skin. First, we tested the effects of caffeine on cell proliferation, differentiation, adhesion and migration, processes essential for normal wound epithelialisation and closure. We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) proliferation assay to test the effects of seven different caffeine doses ranging from 0·1 to 5 mM. We found that caffeine restricted cell proliferation of keratinocytes in a dose-dependent manner. Furthermore, scratch wound assays performed on keratinocyte monolayers indicated dose-dependent delays in cell migration. Interestingly, adhesion and differentiation remained unaffected in monolayer cultures treated with various doses of caffeine. Using a human ex vivo wound healing model, we tested topical application of caffeine and found that it impedes epithelialisation, confirming in vitro data. We conclude that caffeine, which is known to have antioxidant properties, impedes keratinocyte proliferation and migration, suggesting that it may have an inhibitory effect on wound healing and epithelialisation. Therefore, our findings are more in support of a role for caffeine as adenosine-receptor antagonist that would negate the effect of adenosine in promoting wound healing.

Description: In May 2006 high-resolution measurements using ground-penetrating radar (GPR) and magnetic gradiometer systems conducted over selected areas at the site of the Viking Age settlement and trading place Birka in central Sweden demonstrated the suitability of these methods for archaeological prospection of Scandinavian proto-urban settlements. The non-invasive geophysical surveys revealed numerous structural details of the settlement: houses, property boundaries, track-ways, buried remains of the town ramparts dating from different building periods, including a gate, were mapped with a manually operated single-channel GPR system and a four-channel magnetometer array. The combination of these two prospection methods, state-of-the-art data processing and visualization and archaeological interpretation within a geographical information system resulted in valuable new information about the UNESCOWorld Cultural Heritage Site Birka-Hovgården.We present methodology and results of this first archaeological prospection case study conducted in 2006.

Description: The eastern Mediterranean transient (EMT) was caused by a combination of high‐salinity waters intruding into the Aegean Sea and the two particularly strong winters of 1991–1992 and 1992–1993. The approach in this chapter is to search for specific signatures in the historic hydrographic observations, which date back to 1910. To deal with the problem that up into the 1950s the data not only are of limited precision but also have gaps of about 20 years, it is advantageous to consider the fact that the evolution of the actual EMT is rather well documented over a similar time span. The chapter begins by outlining the characteristics of the current EMT. Thereafter, a selection of suitable hydrographic observations among the available historic data is provided to compare these with signatures expected from the evolution of the actual EMT.

Description: The geochemical features of the volatiles dissolved in artesian thermal waters discharged over three basins (Millungera, Galilee and Cooper basin) of the Australian Great Artesian Basin (GAB) consistently indicate the presence of fluids from multiple gas sources located in the crust (e.g. sediments, oil reservoirs, granites) as well as minor but detectable contributions of mantle/magma-derived fluids. The gases extracted from 19 water samples and analyzed for their chemical and isotopic composition exhibit amounts of CO2 up to about 340 mlSTP/LH2O marked by a δ13CTDC (Total Dissolved Carbon) ranging from − 16.9 to + 0.18‰ vs PDB, while CH4 concentrations vary from 4.4 × 10− 5 to 4.9 mlSTP/LH2O. Helium contents were between 9 and 〉 2800 times higher than equilibrium with Air Saturated Water (ASW), with a maximum value of 0.12 mlSTP/LH2O. Helium isotopic composition was in the 0.02–0.21 Ra range (Ra = air-normalized 3He/4He ratio). The three investigated basins differ from each other in terms of both chemical composition and isotopic signatures of the dissolved gases whose origin is attributed to both mantle and crustal volatiles. Mantle He is present in the west-central and hottest part of the GAB despite no evidence of recent volcanism. We found that the partial pressure of helium, significantly higher in crustal fluids than in mantle-type volatiles, enhances the crustal He signature in the dissolved gases, thus masking the original mantle contribution. Neotectonic activity involving deep lithospheric structures and magma intrusions, highlighted by recent geophysical investigations, is considered to be the drivers of mantle/magmatic volatiles towards the surface. The results, although pertaining to artesian waters from a vast area of 〉 542,000 km2, provide new constraints on volatile injection, and show that fluids' geochemistry can provide additional and independent information on the geo-tectonic settings of the Great Artesian Basin and its geothermal potential.

Description: This study presents a new estimate of the oceanic anthropogenic CO2(Cant) sink over the industrial era (1780 to present), from assimilation of potential temperature, salinity, radiocarbon, and CFC-11 observations in a global steady state ocean circulation inverse model (OCIM). This study differs from previous data-based estimates of the oceanic Cant sink in that dynamical constraints on ocean circulation are accounted for, and the ocean circulation is explicitly modeled, allowing the calculation of oceanic Cant storage, air-sea fluxes, and transports in a consistent manner. The resulting uncertainty of the OCIM-estimated Cant uptake, transport, and storage is significantly smaller than the comparable uncertainty from purely data-based or model-based estimates. The OCIM-estimated oceanic Cant storage is 160–166 PgC in 2012, and the oceanic Cant uptake rate averaged over the period 2000–2010 is 2.6 PgC yr−1 or about 30% of current anthropogenic CO2 emissions. This result implies a residual (primarily terrestrial) Cant sink of about 1.6 PgC yr−1 for the same period. The Southern Ocean is the primary conduit for Cant entering the ocean, taking up about 1.1 PgC yr−1 in 2012, which represents about 40% of the contemporary oceanic Cant uptake. It is suggested that the most significant source of remaining uncertainty in the oceanic Cant sink is due to potential variability in the ocean circulation over the industrial era.

Description: Contemporary genetic diversity is the product of both historical and contemporary forces, such as climatic and geological processes affecting range distribution and continuously moulded by evolutionary forces selection, gene flow and genetic drift. Predatory freshwater fishes, such as Northern Pike Esox lucius, commonly exhibit small population sizes, and several local populations are considered endangered. Pike inhabit diverse habitat types, including lakes, rivers and brackish marine waters, thus spanning from small isolated patches to large open marine systems. However, pike population structure from local to regional scales is relatively poorly described, in spite of its significance to developing conservation measures. We analysed microsatellite variation in a total of 1185 North European pike from 46 samples collected across both local and regional scales, as well as over time, to address two overarching questions: Is pike population structure associated with local and/or regional connectivity patterns, and which factors likely have the main influence on the contemporary distribution of genetic diversity? To answer this, we combined estimators of population diversity and structure to assess evidence of whether populations within (i) habitats, (ii) drainage systems and (iii) geographical regions are closer related than among these ranges, and whether patterns are temporally stable. Contrasting previous predictions that genetic drift obscures signals of postglacial colonisation history, we identified clear regional differences in population genetic signatures, suggesting a major effect of drainage divides on colonisation history and connectivity. However, several populations deviated from the general pattern, showing that local processes may be complex and need to be examined case-by-case.

Description: Correlations between particulate organic carbon (POC) and mineral fluxes in the deep ocean have inspired the inclusion of “ballast effect” parameterizations in carbon cycle models. A recent study demonstrated regional variability in the effect of ballast minerals on the flux of POC in the deep ocean. We have undertaken a similar analysis of shallow export data from the Arctic, Atlantic, and Southern Oceans. Mineral ballasting is of greatest importance in the high-latitude North Atlantic, where 60% of the POC flux is associated with ballast minerals. This fraction drops to around 40% in the Southern Ocean. The remainder of the export flux is not associated with minerals, and this unballasted fraction thus often dominates the export flux. The proportion of mineral-associated POC flux often scales with regional variation in export efficiency (the proportion of primary production that is exported). However, local discrepancies suggest that regional differences in ecology also impact the magnitude of surface export. We propose that POC export will not respond equally across all high-latitude regions to possible future changes in ballast availability.

Description: Because the vast majority of species are well diverged, relatively little is known about the genomic architecture of speciation during the early stages of divergence. Species within recent evolutionary radiations are often minimally diverged from a genomic perspective, and therefore provide rare opportunities to address this question. Here, we leverage the hamlet radiation (Hypoplectrus spp., brightly coloured reef fishes from the tropical western Atlantic) to characterize genomic divergence during the early stages of speciation. Transect surveys and spawning observations in Belize, Honduras and Panama confirm that sympatric barred (H. puella), black (H. nigricans) and butter (H. unicolor) hamlets are phenotypically distinct and reproductively isolated, although hybrid spawnings and individuals with intermediate phenotypes are seen on rare occasions. A survey of approximately 100 000 restriction site-associated SNPs in 126 samples from the three species across the three replicate populations reveals extremely slight genomewide divergence among species (FST = 0.0038), indicating that ecomorphological differences and functional reproductive isolation are maintained in sympatry in a backdrop of extraordinary genomic similarity. Nonetheless, a very small proportion of SNPs (0.05% on average) are identified as FST outliers among sympatric species. Remarkably, a single SNP is identified as an outlier in repeated populations for the same species pair. A minicontig assembled de novo around this SNP falls into the genomic region containing the HoxCa10 and HoxCa11 genes in 10 teleost species, suggesting an important role for Hox gene evolution in this radiation. This finding, if confirmed, would provide a better understanding of the links between micro- and macroevolutionary processes.

Description: The final phase of the closure of the Panamanian Gateway and the intensification of Northern Hemisphere Glaciation (NHG) both occurred during the Late Pliocene. Glacial–interglacial (G–IG) variations in sea level might, therefore, have had a significant impact on the remaining connections between the East Pacific and the Caribbean. Here, we present combined foraminiferal Mg/Ca and δ 18O measurements from Ocean Drilling Program (ODP) Site 1241 from the East Pacific and ODP Site 999 from the Caribbean. The studied time interval covers the first three major G–IG Marine Isotope Stages (MIS 95–100, ∼2.5 Ma∼2.5 Ma) after the intensification of NHG. Analyses were performed on the planktonic foraminifera Neogloboquadrina dutertrei and Globigerinoides sacculifer, representing water mass properties in the thermocline and the mixed-layer, respectively. Changes in sea water temperature, relative salinity, and water column stratification strongly suggest that the Panamanian Gateway temporarily closed during glacial MIS 98 and 100, as a result of changes in ice volume equivalent to a drop in sea level of 60–90 m. Reconstructed sea surface temperatures (SST) from G. sacculifer show a glacial decrease of 2.5 °C at Site 1241, but increases of up to 3 °C at Site 999 during glacial MIS 98 and 100 suggesting that the Panamanian Gateway closed during these glacial periods. The Mg/Ca-temperatures of N. dutertrei remain relatively stable in the East Pacific, but do show a 3 °C warming in the Caribbean at the onset of these glacial periods suggesting that the closing of the gateway also changed the water column stratification. We infer that the glacial closure of the gateway allowed the Western Atlantic Warm Pool to extend into the southern Caribbean, increasing SST (G. sacculifer) and deepening the thermocline (N. dutertrei). Additionally, ice volume appears to have become large enough during MIS 100 to survive the relatively short lasting interglacial MIS 99 so that the gateway remained closed. Towards the end of MIS 98, during MIS 97 and into MIS 96 temperatures on both sides are mostly similar suggesting water masses exchanged again. Additionally, Caribbean variations in SST and δ18Owater follow a precession-like cyclicity rather than the obliquity-controlled variations characteristic of the East Pacific and many other tropical areas, suggesting that regional atmospheric processes related to the trade winds and the InterTropical Convergence Zone (ITCZ) had a dominant impact in the Caribbean.

Description: In the vast Low Nutrient Low-Chlorophyll (LNLC) Ocean, the vertical nutrient supply from the subsurface to the sunlit surface waters is low, and atmospheric contribution of nutrients may be one order of magnitude greater over short timescales. The short turnover time of atmospheric Fe and N supply (〈1 month for nitrate) further supports deposition being an important source of nutrients in LNLC regions. Yet, the extent to which atmospheric inputs are impacting biological activity and modifying the carbon balance in oligotrophic environments has not been constrained. Here, we quantify and compare the biogeochemical impacts of atmospheric deposition in LNLC regions using both a compilation of experimental data and model outputs. A metadata-analysis of recently conducted field and laboratory bioassay experiments reveals complex responses, and the overall impact is not a simple “fertilization effect of increasing phytoplankton biomass” as observed in HNLC regions. Although phytoplankton growth may be enhanced, increases in bacterial activity and respiration result in weakening of biological carbon sequestration. The application of models using climatological or time-averaged non-synoptic deposition rates produced responses that were generally much lower than observed in the bioassay experiments. We demonstrate that experimental data and model outputs show better agreement on short timescale (days to weeks) when strong synoptic pulse of aerosols deposition, similar in magnitude to those observed in the field and introduced in bioassay experiments, is superimposed over the mean atmospheric deposition fields. These results suggest that atmospheric impacts in LNLC regions have been underestimated by models, at least at daily to weekly timescales, as they typically overlook large synoptic variations in atmospheric deposition and associated nutrient and particle inputs. Inclusion of the large synoptic variability of atmospheric input, and improved representation and parameterization of key processes that respond to atmospheric deposition, is required to better constrain impacts in ocean biogeochemical models. This is critical for understanding and prediction of current and future functioning of LNLC regions and their contribution to the global carbon cycle.

Description: The impact of mesoscale activity on phytoplankton and nutrient distribution in the Mozambique Channel was simulated by coupling a biogeochemical model (PISCES) with a regional oceanic model (ROMS). Examples of the effects of eddies on the biogeochemistry of the Mozambique Channel are presented to illustrate the complexity of the system. In the model, several cyclonic eddies were found with low concentrations of chlorophyll at their cores, which contrasts with previous studies in the open ocean. In addition, several anticyclonic eddies were simulated with high concentrations of chlorophyll at their cores. Phytoplankton growth within these mesoscale features (both cyclonic and anticyclonic eddies) occurred in response to nutrient injection into the euphotic zone by advection, and subsequent retention of surrounding nutrient-rich waters within eddies. Offshore nutrient distributions depended strongly on lateral advection of nutrient-rich water from the coastal regions, induced by eddy interaction with the shelf. The environmental conditions at the locations where eddies were generated had an important effect on nutrient concentrations within these structures.

Description: Highlights: • A DEB model for M. leidyi was parameterized using 60 datasets from literature. • 12 °C might already be outside the optimal temperature range. • M. leidyi has high reserve turnover rates and a high structural component. • Delayed metabolic acceleration confers flexibility in controlling generation time. Abstract: Mnemiopsis leidyi is an invasive comb jelly which has successfully established itself in European seas. The species is known to produce spectacular blooms yet it is holoplanktonic and not much is known about its population dynamics in between. One way to gain insight on how M. leidyi might survive between blooms and how it can bloom so fast is to study how the metabolism of this species actually responds to environmental changes in food and temperature over its different life-stages. To this end we combined modelling and data analysis to study the energy budget of M. leidyi over its full life-cycle using Dynamic Energy Budget (DEB) theory and literature data. An analysis of data obtained at temperatures ranging from 8 to 30 °C suggests that the optimum thermal tolerance range of M. leidyi is higher than 12 °C. Furthermore M. leidyi seems to undergo a so-called metabolic acceleration after hatching. Intriguingly, the onset of the acceleration appears to be delayed and the data do not yet exist which allows determining what actually triggers it. It is hypothesised that this delay confers a lot of metabolic flexibility by controlling generation time. We compared the DEB model parameters for this species with those of another holoplanktonic gelatinous zooplankton species (Pelagia noctiluca). After accounting for differences in water content, the comparison shows just how fundamentally different the two energy allocation strategies are. P. noctiluca has an extremely high reserve capacity, low turnover times of reserve compounds and high resistance to shrinking. M. leidyi adopts the opposite strategy: it has a low reserve capacity, high turnover rates of reserve compounds and fast shrinking.

Description: Epsilonproteobacteria have been found globally distributed in marine anoxic/sulfidic areas mediating relevant transformations within the sulfur and nitrogen cycles. In the Baltic Sea redox zones, chemoautotrophic epsilonproteobacteria mainly belong to the Sulfurimonas gotlandica GD17 cluster for which recently a representative strain, S. gotlandica GD1T, could be established as a model organism. In this study, the potential effects of changes in dissolved inorganic carbon (DIC) and pH on S. gotlandica GD1T were examined. Bacterial cell abundance within a broad range of DIC concentrations and pH values were monitored and substrate utilization was determined. The results showed that the DIC saturation concentration for achieving maximal cell numbers was already reached at 800 μmol L−1, which is well below in situ DIC levels. The pH optimum was between 6.6 and 8.0. Within a pH range of 6.6–7.1 there was no significant difference in substrate utilization; however, at lower pH values maximum cell abundance decreased sharply and cell-specific substrate consumption increased.

Description: Total organic carbon (TOC) content of marine sediments represents residual carbon, originally derived from terrestrial and marine sources, which has survived seafloor and shallow subseafloor diagenesis. Ultimately, its preservation below the sulfate reduction zone in marine sediments drives methanogenesis. Within the gas hydrate stability zone (GHSZ), methane production along continental margins can supersaturate pore fluids and lead to the formation of gas hydrate. In this paper we examine the inventory and sources of TOC in sediments collected from four regions within the GHSZ along the Indian continental margins. The recovered sediments vary in age from Oligocene to recent. Mean TOC abundance is greatest in the Krishna-Godavari (K-G) Basin and decreases progressively to the Mahanadi basin, Andaman wedge, and Kerala-Konkan (K-K) Basin. This decrease in TOC is matched by a progressive increase in biogenic CaCO3 and increasing distance from terrestrial sources of organic matter and lithogenic materials. Organic carbon sources inferred from C/N and delta C-13(TOC) range from terrestrial (K-G Basin) to mixed marine and terrestrial (Mahanadi Basin), to marine dominant (Andaman wedge and K-K Basin). In the K-G Basin, variation in the bulk delta C-13(TOC) is consistent with changes in C-3 and C-4 vegetation driven by monsoon variability on glacial-interglacial timescales, whereas in the Mahanadi Basin a shift in the delta C-13(TOC) likely reflects the onset of C-4 plant deposition in the Late Miocene. A large shift the delta C-13(TOC) in the K-K basin is consistent with a change from C-3 to C-4 dominated plants during the middle Miocene. We observe a close relationship between TOC content and gas hydrate saturation, but consider the role of sedimentation rates on the preservation of TOC in the zone of methanogenesis and advective flow of methane from depth. Although TOC contents are sufficient for in situ methanogenesis at all the sites where gas hydrates were observed or inferred from proxy data, seismic, borehole log, pressure core, and gas composition data coupled with relatively high observed gas hydrate saturations suggest that advective gas transport may also play a role in the saturation of methane and the formation of gas hydrates in these regions. Although TOC content may be a first order indicator for gas hydrate potential, the structural and stratigraphic geologic environment along a margin will most likely dictate where the greatest gas hydrate saturations will occur.

Description: Though primarily driven by insolation changes associated with well-known variations in Earth's astronomical parameters, the response of the climate system during interglacials includes a diversity of feedbacks involving the atmosphere, ocean, sea ice, vegetation and land ice. A thorough multi-model-data comparison is essential to assess the ability of climate models to resolve interglacial temperature trends and to help in understanding the recorded climatic signal and the underlying climate dynamics. We present the first multi-model-data comparison of transient millennial-scale temperature changes through two intervals of the Present Interglacial (PIG; 8-1.2 ka) and the Last Interglacial (LIG; 123-116.2 ka) periods. We include temperature trends simulated by 9 different climate models, alkenone-based temperature reconstructions from 117 globally distributed locations (about 45% of them within the LIG) and 12 ice-core-based temperature trends from Greenland and Antarctica (50% of them within the LIG). The definitions of these specific interglacial intervals enable a consistent inter-comparison of the two intervals because both are characterised by minor changes in atmospheric greenhouse gas concentrations and more importantly by insolation trends that show clear similarities. Our analysis shows that in general the reconstructed PIG and LIG Northern Hemisphere mid-to-high latitude cooling compares well with multi-model, mean-temperature trends for the warmest months and that these cooling trends reflect a linear response to the warmest-month insolation decrease over the interglacial intervals. The most notable exception is the strong LIG cooling trend reconstructed from Greenland ice cores that is not simulated by any of the models. A striking model-data mismatch is found for both the PIG and the LIG over large parts of the mid-to-high latitudes of the Southern Hemisphere where the data depicts negative temperature trends that are not in agreement with near zero trends in the simulations. In this area, the positive local summer insolation trend is counteracted in climate models by an enhancement of the Southern Ocean summer sea-ice cover and/or an increase in Southern Ocean upwelling. If the general picture emerging from reconstructions is realistic, then the model-data mismatch in mid and high Southern Hemisphere latitudes implies that none of the models is able to resolve the correct balance of these feedbacks, or, alternatively, that interglacial Southern Hemisphere temperature trends are driven by mechanisms which are not included in the transient simulations, such as changes in the Antarctic ice sheet or meltwater-induced changes in the overturning circulation

Description: Harmful, bloom-forming cyanobacteria (CyanoHABs) are occurring with increasing regularity in freshwater and marine ecosystems. The most commonly occurring cyanobacterial toxins are the hepatotoxic microcystin and nodularin. These cyclic hepta- and pentapeptides are synthesised nonribosomally by the gene products of the toxin gene clusters mcy and nda, respectively. Understanding of the regulation of hepatotoxin production is incomplete, although there is strong evidence supporting the roles of iron, light, higher nitrate availability and inorganic carbon in modulating microcystin levels. The majority of these studies have focused on the unicellular freshwater, microcystin-producing strain of Microcystis aeruginosa, with little attention being paid to terrestrial or marine toxin producers. This review intends to investigate the regulation of microcystin and nodularin production in unicellular and filamentous diazotrophic cyanobacteria against the background of changing climate conditions. Special focus is given to diazotrophic filamentous cyanobacteria, for example Nodularia spumigena, capable of regulating their nitrogen levels by actively fixing dinitrogen. By combining data from significant studies, an overall scheme of the regulation of toxin production is presented, focussing specifically on nodularin production in diazotrophs against the background of increasing carbon dioxide concentrations and temperatures envisaged under current climate change models. Furthermore, the risk of sustaining and spreading CyanoHABs in the future ocean is evaluated.

Description: We show that the Li/Mg systematics of a large suite of aragonitic coral skeletons, representing a wide range of species inhabiting disparate environments, provides a robust proxy for ambient seawater temperature. The corals encompass both zooxanthellate and azooxanthellate species (Acropora sp., Porites sp., Cladocora caespitosa, Lophelia pertusa, Madrepora oculata and Flabellum impensum) collected from shallow, intermediate, and deep-water habitats, as well as specimens cultured in tanks under temperature-controlled conditions. The Li/Mg ratios observed in corals from these diverse tropical, temperate, and deep-water environments are shown to be highly correlated with temperature, giving an exponential temperature relationship of: Li/Mg (mmol/mol) = 5.41 exp (−0.049 * T) (r2 = 0.975, n = 49). Based on the standard error of the Li/Mg versus temperature correlation, we obtain a typical precision of ±0.9 °C for the wide range of species analysed, similar or better than that of other less robust coral temperature proxies such as Sr/Ca ratios. The robustness and species independent character of the Li/Mg temperature proxy is shown to be the result of the normalization of Li to Mg, effectively eliminating the precipitation efficiency component such that temperature remains as the main controller of coral Li/Mg compositions. This is inferred from analysis of corresponding Li/Ca and Mg/Ca ratios with both ratios showing strong microstructure-related co-variations between the fibrous aragonite and centres of calcification, a characteristic that we attribute to varying physiological controls on growth rate. Furthermore, Li/Ca ratios show an offset between more rapidly growing zooxanthellate and azooxanthellate corals, and hence only an approximately inverse relationship to seawater temperature. Mg/Ca ratios show very strong physiological controls on growth rate but no significant dependence with temperature, except possibly for Acropora sp. and Porites sp. A strong positive correlation is nevertheless found between Li/Ca and Mg/Ca ratios at similar temperatures, indicating that both Li and Mg are subject to control by similar growth mechanisms, specifically the mass fraction of aragonite precipitated during calcification, which is shown to be consistent with a Rayleigh-based elemental fractionation model. The highly coherent array defined by Li/Mg versus temperature is thus largely independent of coral calcification mechanisms, with the strong temperature dependence reflecting the greater sensitivity of the KdLi/Ca partition coefficient relative to KdMg/Ca. Accordingly, Li/Mg ratios exhibit a highly coherent exponential correlation with temperature, thereby providing a more robust tool for reconstructing paleo-seawater temperatures.

Description: A key challenge in oceanography is to capture and quantify processes that happen on short time scales, seasonal changes and inter-annual variations. To address this problem the P&O European Ferries Ltd. Ship MV Pride of Bilbao was fitted with a FerryBox from 2002 to 2010 and data returned to NOC in real time providing near continuous measurements between UK (Portsmouth) and Spain (Bilbao) of temperature, salinity, chlorophyll-fluorescence and oxygen. Additional monthly samples were collected on manned crossings. Over 6000 samples were analysed for nitrate (nitrate and nitrite) concentrations. The timing of nitrate concentration increases (with winter mixing) and decreases (with the spring bloom) are different on and off shelf and in autumn nitrate concentrations remain high on the shelf. Off shelf in the Bay of Biscay, the mixed layer depth assessed using Argo floats, was found to vary from 212 m in relatively mild winters (such as 2007/2008) to 476 m in cold winters (2009/2010). Years with deeper mixing were associated with an increase in nitrate concentrations in the surface waters (~3 μmol l−1) and the increased vertical nutrient supply resulted in higher productivity the following spring. Bloom progression could be seen through the increase in oxygen anomaly and decrease in nitrate concentrations off shelf prior to changes further north on the shelf and phytoplankton growth was initiated as shoaling begins. The full dataset demonstrates that ships of opportunity, particularly ferries with consistently repeated routes, can deliver high quality in situ measurements over large time and space scales that currently cannot be delivered in any other way.

Description: 1. Macroecology has prospered in recent years due in part to the wide array of climatic data, such as those provided by theWorldClim and CliMond data sets, which has become available for research. However, important environmental variables have still been missing, including spatial data sets on UV-B radiation, an increasingly recognized driver of ecological processes. 2. We developed a set of globalUV-B surfaces (glUV) suitable to match common spatial scales in macroecology. Our data set is based on remotely sensed records fromNASA’sOzone Monitoring Instrument (Aura-OMI). Following a similar approach as for theWorldClim and CliMond data sets, we processed daily UV-B measurements acquired over a period of eight years into monthly mean UV-B data and six ecologically meaningful UV-B variables with a 15-arc minute resolution. These bioclimatic variables represent Annual Mean UV-B, UV-B Seasonality, Mean UV-B of Highest Month, Mean UV-B of Lowest Month, Sum of Monthly Mean UV-B during Highest Quarter and Sum of Monthly Mean UV-B during Lowest Quarter. We correlated our data sets with selected variables of existing bioclimatic surfaces for land and with Terra–MODIS Sea Surface Temperature for ocean regions to test for relations to known gradients and patterns. 3. UV-B surfaces showed a distinct seasonal variance at a global scale, while the intensity of UV-B radiation decreased towards higher latitudes and was modified by topographic and climatic heterogeneity. UV-B surfaces were correlated with global mean temperature and annual mean radiation data, but exhibited variable spatial associations across the globe.UV-B surfaces were otherwise widely independent of existing bioclimatic surfaces. 4. Our data set provides new climatological information relevant for macroecological analyses. As UV-B is a known driver of numerous biological patterns and processes, our data set offers the potential to generate a better understanding of these dynamics inmacroecology, biogeography, global change research and beyond. The glUV data set containing monthly mean UV-B data and six derived UV-B surfaces is freely available for download at: http://www.ufz.de/gluv.

Description: Highlights • Climate progression in the Balearic basin is examined between 140 and 100 ka. • A number of MIS 5e intra-interglacial cooling events is recognized. • MIS 5e climate phasing in the Western Mediterranean resembles the one in the Nordic Seas. • Foraminiferal abundances are strongly tied to a water circulation regime. • The timing of ORL deposition during MIS 5e resembles that of during the Holocene. Abstract A multiproxy analysis based on planktic foraminiferal abundances, derived SSTs, and stable planktic isotopes measurements together with alkenone abundances and Uk′37 SSTs was performed on late MIS 6 to early MIS 5d sediment recovered from Site 975 (ODP Leg 161) in the South Balearic Islands Basin (Western Mediterranean) with emphasis on reconstructing the climate progression of the last interglacial period. A number of abrupt climate changes related to alternative influence of nutrient rich northern and oligotrophic southern water masses was revealed. Heinrich event 11 and cooling events C27, C26, C25, C24, and C23, which have been previously described in the North Atlantic, were recognized. However, in comparison to the eastern North Atlantic mid-latitude region, events C27 and C26 at Site 975 seem to be significantly more pronounced. Together with evidence of a two-phase climate optimum with maximum SSTs reached during its later phase, this implies a close similarity in climate dynamics between the Western Mediterranean and the Nordic seas. We propose that postglacial effects in the Nordic seas had an influence on the western Mediterranean climate via atmospheric circulation and that these effects competed with the insolation force.

Description: Natural antifouling products have been the subject of considerable attention. We screened marine algae for antifouling activity and discovered omaezallenes, the new bromoallene-containing natural products isolated from the red alga Laurencia sp. Described is the isolation, structure elucidation, and total syntheses of omaezallenes. The relative and absolute configurations of natural omaezallenes were unambiguously established through total synthesis. The antifouling activities and ecotoxicity of omaezallenes were also evaluated.

Description: Marine sponge-associated actinomycetes represent an exciting new resource for the identification of new and novel natural products . Previously, we have reported the isolation and structural elucidation of actinosporins A (1) and B (2) from Actinokineospora sp. strain EG49 isolated from the marine sponge Spheciospongia vagabunda. Herein, by employing different fermentation conditions on the same microorganism, we report on the isolation and antioxidant activity of structurally related metabolites, actinosporins C (3) and D (4). The antioxidant potential of actinosporins C and D was demonstrated using the ferric reducing antioxidant power (FRAP) assay. Additionally, at 1.25 μM, actinosporins C and D showed a significant antioxidant and protective capacity from the genomic damage induced by hydrogen peroxide in the human promyelocytic (HL-60) cell line.

Description: Microluside A [4 (19-para-hydroxy benzoyloxy-O-β-d-cellobiosyl), 5 (30-para-hydroxy benzoyloxy-O-β-d-glucopyranosyl) xanthone (1)] is a unique O-glycosylated disubstituted xanthone isolated from the broth culture of Micrococcus sp. EG45 cultivated from the Red Sea sponge Spheciospongia vagabunda. The structure of microluside A was determined by 1D- and 2D-NMR techniques as well as high resolution tandem mass spectrometry. The antimicrobial activity evaluation showed that 1 exhibited antibacterial potential against Enterococcus faecalis JH212 and Staphylococcus aureus NCTC 8325 with MIC values of 10 and 13 μM, respectively.

Description: Highlights • Seismic imaging of gas hydrate deposits in the Mahanadi Basin shows strong linkages to channel/levee structures. • Gas hydrate occurs only in discrete layers, stratigraphically bound. • Gas hydrate saturation was determined successfully from log and core data. • Saturation estimates show overall low values of up to 10% in discrete layers. Abstract Gas hydrate was recovered in the Mahanadi Basin along the eastern continental margin of India during the India National Gas Hydrate Program (NGHP) Expedition-01 in 2006. Infrared imaging of recovered core confirmed gas hydrate occurs predominantly in discrete layers. Pore-water chemistry, electrical resistivity and acoustic velocity down-hole logs were used to estimate gas hydrate saturations at three of the sites in the Mahanadi Basin: Sites NGHP-01-08, -09, and -19. Gas hydrate saturation estimated from pore-water chloride concentrations shows values up to ∼10% of the pore space at ∼200 m below seafloor just above the base of the gas hydrate stability zone (BGHSZ). Gas hydrate saturations estimated from electrical resistivity and acoustic velocity logs using standard relations and modeling approaches are comparable to each other and saturations are ∼10–15% of the pore space. Seismic reflection data were also analyzed for the evidence of gas hydrate, and a bottom-simulating reflector (BSR) was imaged along the seismic profiles in the study area. The depth of the BSR is varying from ∼200 m to ∼300 m below seafloor depending on water depth in the Mahanadi Basin. The occurrence of gas hydrate was observed to be associated with deep-water channel and levee complexes (especially at Site NGHP-01-19) based on the regional seismic data. But the cored/logged section at each site lacked any significant sand fraction, which does not allow for higher gas hydrate saturations. As identified from seismic time-slice data, all sites drilled in the Mahanadi Basin are within the steeper slope region of the channel system and any sand bypassed this region. Significant sand deposition would occur further down slope where typical fan-type deposits can be inferred from the seismic data and thus higher accumulations of gas hydrate would be expected.

Description: Highlights • Regional difference in Vp and Vs are related to grain-size distribution. • New algorithm to derive gas hydrate concentration from Vp and Vs is introduced. • Sediments from northern Cascadia are similar to Arctic gas hydrate settings. • New empirical relationships for shear-wave velocities are defined. Abstract Shear wave velocity data have been acquired at several marine gas hydrate drilling expeditions, including the India National Gas Hydrate Program Expedition 1 (NGHP-01), the Ocean Drilling Program (ODP) Leg 204, and Integrated Ocean Drilling Program (IODP) Expedition 311 (X311). In this study we use data from these marine drilling expeditions to develop an understanding of general grain-size control on the P- and S-wave properties of sediments. A clear difference in the downhole trends of P-wave (Vp) and S-wave (Vs) velocity and the Vp/Vs ratio from all three marine regions was observed: the northern Cascadia margin (IODP X311) shows the highest P-wave and S-wave velocity values overall and those from the India margin (Expedition NGHP-01) are the lowest. The southern Cascadia margin (ODP Leg 204) appears to have similar low P-wave and S-wave velocity values as seen off India. S-wave velocity values increase relative to the sites off India, but they are not as high as those seen on the northern Cascadia margin. Such regional differences can be explained by the amount of silt/sand (or lack thereof) occurring at these sites, with northern Cascadia being the region of the highest silt/sand occurrences. This grain-size control on P-wave and S-wave velocity and associated mineral composition differences is amplified when compared to the Arctic permafrost environments, where gas hydrate predominantly occurs in sand- and silt-dominated formations. Using a cross-plot of gamma ray values versus the Vp/Vs ratio, we compare the marine gas hydrate occurrences in these regions: offshore eastern India margin, offshore Cascadia margin, the Ignik-Sikumi site in Alaska, and the Mallik 5L-38 site in the Mackenzie Delta. The log-data from the Arctic permafrost regions show a strongly linear Vp–Vs relationship, similar to the previously defined empirical relationships by Greenberg and Castagna (1992). P- and S-wave velocity data from the India margin and ODP Leg 204 deviate strongly from these linear trends, whereas data from IODP X311 plot closer to the trend of the Arctic data sets and previously published relationships. Three new linear relationships for different grain size marine sediment hosts are suggested: a) mud-dominated (Mahanadi Basin, ODP Leg 204 & NGHP-01-17): Vs = 1.5854 × Vp − 2.1649 b) silty-mud (KG Basin): Vs = 0.8105 × Vp − 1.0223 c) silty-sand (IODP X311): Vs = 0.5316 × Vp − 0.4916 We investigate the relationship of gas hydrate saturation determined from electrical resistivity on the Vp/Vs ratio and found that the sand-dominated Arctic hosts show a clearly decreasing trend of Vp/Vs ratio with gas hydrate saturation. Though limited due to lower overall GH saturations, a similar trend is seen for sites from IODP X311 and at the ash-dominated NGHP-01-17 sediment in the Andaman Sea. Gas hydrate that occurs predominantly in fractured clay hosts show a different trend where the Vp/Vs ratio is much higher than at sand-dominated sites and remains constant or increases slightly with increasing gas hydrate saturation. This trend may be the result of anisotropy in fracture-dominated systems, where P- and S-wave velocities appear higher and Archie-based saturations of gas hydrate are overestimated. Gas hydrate concentrations were also estimated in these three marine settings and at Arctic sites using an effective medium model, combining P- and S-wave velocities as equally weighted constraints on the calculation. The effective medium approach generally overestimates S-wave velocity in high-porosity, clay-dominated sediments, but can be accurately used in sand-rich formations.

Description: Highlights: • The central uplift of the Manicouagan impact structure has been dated by (U–Th)/He • A (U–Th)/He central age (207.1 ± 6.4 Ma, 2 standard error, n = 40) has been determined • This age reflects the rapid uplift, cooling and closure of He in ~ 1 Gyr-old titanites • This correlates with the previously determined U–Pb impact-melt age of 214 ± 1 Ma • Our new approach enables dating complex impact structures that lack impact melt rocks Abstract Forty titanite grain fragments from 9 central uplift samples of metamorphosed anorthosite from the Manicouagan impact structure were dated by the (U–Th)/He technique. A (U–Th)/He central age of 207.1 ± 6.4 Ma (2 standard error (SE), n = 40) has been determined. With 4 outlier ages removed the central age is refined to 208.9 ± 5.1 Ma (2 SE). Both of these ages are within error of the previously determined U–Pb zircon age of 214 ± 1 Ma (2σ) derived from the impact melt. Manicouagan's central uplift formed due to rapid elevation from ~ 7–10 km depth as part of the modification stage of the impact process, which has facilitated the dating of its emplacement due to resulting rapid exhumation and cooling and closure of the (U–Th)/He system in titanite. Correlation with the previous U–Pb zircon 214 ± 1 Ma impact melt crystallization age indicates that the (U–Th)/He titanite dating technique offers a new approach to dating complex impact structures in the absence of viable melt sheets, or other melt products. The youngest ca. 195 Ma (U–Th)/He dates preserved in some titanite fragments are synchronous with Early Jurassic, rift-induced lithospheric thinning and associated igneous activity that defines the Central Atlantic Magmatic Province (CAMP). The (U–Th)/He titanite data from Manicouagan indicate that the influence of this regional event may extend west of the previously proposed limit of CAMP activity.

Description: Gas hydrate resource assessments that indicate enormous global volumes of gas present within hydrate accumulations have been one of the primary driving forces behind the growing interest in gas hydrates. Gas hydrate volumetric estimates in recent years have focused on documenting the geologic parameters in the “gas hydrate petroleum system” that control the occurrence of gas hydrates in nature. The primary goals of this report are to review our present understanding of the geologic controls on the occurrence of gas hydrate in the offshore of India and to document the application of the petroleum system approach to the study of gas hydrates. National Gas Hydrate Program of India executed the National Gas Hydrate Program Expedition 01 (NGHP-01) in 2006 in four areas located on the eastern and western margins of the Indian Peninsula and in the Andaman Sea. These areas have experienced very different tectonic and depositional histories. The peninsular margins are passive continental margins resulting from a series of rifting episodes during the breakup and dispersion of Gondwanaland to form the present Indian Ocean. The Andaman Sea is bounded on its western side by a convergent margin where the Indian plate lithosphere is being subducted beneath southeast Asia. NGHP-01 drilled, logged, and/or cored 15 sites (31 holes) in the Krishna–Godavari Basin, 4 sites (5 holes) in the Mahanadi Basin, 1 site (2 holes) in the Andaman Sea, and 1 site (1 hole) in the Kerala–Konkan Basin. Holes were drilled using standard drilling methods for the purpose of logging-while-drilling and dedicated wireline logging; as well as through the use of a variety of standard coring systems and specialized pressure coring systems. NGHP-01 yielded evidence of gas hydrate from downhole log and core data obtained from all the sites in the Krishna–Godavari Basin, the Mahanadi Basin, and in the Andaman Sea. The site drilled in the Kerala–Konkan Basin during NGHP-01 did not yield any evidence of gas hydrate. Most of the downhole log-inferred gas hydrate and core-recovered gas hydrate were characterized as either fracture-filling in clay-dominated sediments or as pore-filling or grain-displacement particles disseminated in both fine- and coarse-grained sediments. Geochemical analyses of gases obtained from sediment cores recovered during NGHP-01 indicated that the gas in most all of the hydrates in the offshore of India is derived from microbial sources; only one site in the Andaman Sea exhibited limited evidence of a thermogenic gas source. The gas hydrate petroleum system concept has been used to effectively characterize the geologic controls on the occurrence of gas hydrates in the offshore of India.

Description: The Indian National Gas Hydrate Program Expedition 01 (NGHP-01) is designed to study the occurrence of gas hydrate along the passive continental margin of the Indian Peninsula and in the Andaman convergent margin, with special emphasis on understanding the geologic and geochemical controls on the occurrence of gas hydrate in these two diverse settings. The NGHP-01 expedition established the presence of gas hydrates in the Krishna–Godavari and Mahanadi Basins, and the Andaman Sea. The expedition discovered in the Krishna–Godavari Basin one of the thickest gas hydrate accumulations ever documented, in the Andaman Sea one of the thickest and deepest gas hydrate stability zones in the world, and established the existence of a fully developed gas hydrate petroleum system in all three basins. The primary goal of NGHP-01 was to conduct scientific ocean drilling/coring, logging, and analytical activities to assess the geologic occurrence, regional context, and characteristics of gas hydrate deposits along the continental margins of India. This was done in order to meet the long-term goal of exploiting gas hydrate as a potential energy resource in a cost effective and safe manner. During its 113.5-day voyage, the D/V JOIDES Resolution cored and/or drilled 39 holes at 21 sites (1 site in Kerala–Konkan, 15 sites in Krishna–Godavari, 4 sites in Mahanadi, and 1 site in the Andaman deep offshore area), penetrated more than 9250 m of sedimentary section, and recovered nearly 2850 m of core. Twelve holes were logged with logging-while-drilling (LWD) tools and an additional 13 holes were wireline logged. The science team utilized extensive on-board laboratory facilities to examine and prepare preliminary reports on the physical properties, geochemistry, and sedimentology of all the data collected prior to the end of the expedition. Samples were also analyzed in additional post-expedition shore-based studies conducted in leading laboratories around the world. One of the specific objectives of this expedition was to test gas hydrate formation models and constrain model parameters, especially those that account for the formation of concentrated gas hydrate accumulations. The necessary data for characterizing the occurrence of in situ gas hydrate, such as interstitial water chlorinities, core-derived gas chemistry, physical and sedimentological properties, thermal images of the recovered cores, and downhole measured logging data (LWD and/or conventional wireline log data), were obtained from most of the drill sites established during NGHP-01. Almost all of the drill sites yielded evidence for the occurrence of gas hydrate; however, the inferred in situ concentration of gas hydrate varied substantially from site to site. For the most part, the interpretation of downhole logging data, core thermal images, interstitial water analyses, and pressure core images from the sites drilled during NGHP-01 indicate that the occurrence of concentrated gas hydrate is mostly associated with the presence of fractures in the sediments, and in some limited cases, by coarser grained (mostly sand-rich) sediments.

Description: Hyperthermophilic iron reducers are common in hydrothermal chimneys found along the Endeavour Segment in the northeastern Pacific Ocean based on culture-dependent estimates. However, information on the availability of Fe(III) (oxyhydr) oxides within these chimneys, the types of Fe(III) (oxyhydr) oxides utilized by the organisms, rates and environmental constraints of hyperthermophilic iron reduction, and mineral end products is needed to determine their biogeochemical significance and are addressed in this study. Thin-section petrography on the interior of a hydrothermal chimney from the Dante edifice at Endeavour showed a thin coat of Fe(III) (oxyhydr) oxide associated with amorphous silica on the exposed outer surfaces of pyrrhotite, sphalerite, and chalcopyrite in pore spaces, along with anhydrite precipitation in the pores that is indicative of seawater ingress. The iron sulfide minerals were likely oxidized to Fe(III) (oxyhydr) oxide with increasing pH and Eh due to cooling and seawater exposure, providing reactants for bioreduction. Culture-dependent estimates of hyperthermophilic iron reducer abundances in this sample were 1740 and 10 cells per gram (dry weight) of material from the outer surface and the marcasite-sphalerite-rich interior, respectively. Two hyperthermophilic iron reducers, Hyperthermus sp. Ro04 and Pyrodictium sp. Su06, were isolated from other active hydrothermal chimneys on the Endeavour Segment. Strain Ro04 is a neutrophilic (pHopt 7–8) heterotroph, while strain Su06 is a mildly acidophilic (pHopt 5), hydrogenotrophic autotroph, both with optimal growth temperatures of 90–92 °C. Mössbauer spectroscopy of the iron oxides before and after growth demonstrated that both organisms form nanophase (〈12 nm) magnetite [Fe3O4] from laboratory-synthesized ferrihydrite [Fe10O14(OH)2] with no detectable mineral intermediates. They produced up to 40 mm Fe2+ in a growth-dependent manner, while all abiotic and biotic controls produced 〈3 mm Fe2+. Hyperthermophilic iron reducers may have a growth advantage over other hyperthermophiles in hydrothermal systems that are mildly acidic where mineral weathering at increased temperatures occurs.

Description: The Fram Strait is the main gateway for water, heat and sea-ice exchanges between the Arctic Ocean and the North Atlantic. The complex physical environment results in a highly variable primary production in space and time. Previous regional studies have defined key bottom-up (ice cover and stratification from melt water controlling the light availability, and wind mixing and water transport affecting the supply of nutrients) and top-down processes (heterotrophic grazing). In this study, in situ field data, remote sensing and modeling techniques were combined to investigate in detail the influence of melting sea-ice and ocean properties on the development of phytoplankton blooms in the Fram Strait region for the years 1998–2009. Satellite-retrieved chlorophyll-a concentrations from temporarily ice-free zones were validated with contextual field data. These were then integrated per month on a grid size of 20 × 20 km, resulting in 10 grids/fields. Factors tested for their influence on spatial and temporal variation of chlorophyll-a were: sea-ice concentration from satellite and sea-ice thickness, ocean stratification, water temperature and salinity time-series simulated by the ice-ocean model NAOSIM. The time series analysis for those ten ice-free fields showed a regional separation according to different physical processes affecting phytoplankton distribution. At the marginal ice zone the melting sea-ice was promoting phytoplankton growth by stratifying the water column and potentially seeding phytoplankton communities. In this zone, the highest mean chlorophyll concentration averaged for the productive season (April–August) of 0.8 mgC/m3 was observed. In the open ocean the phytoplankton variability was correlated highest to stratification formed by solar heating of the upper ocean layers. Coastal zone around Svalbard showed processes associated with the presence of coastal ice were rather suppressing than promoting the phytoplankton growth. During the twelve years of observations, chlorophyll concentrations significantly increased in the southern part of the Fram Strait, associated with an increase in sea surface temperature and a decrease in Svalbard coastal ice. Highlights • We used combination of satellite, simulated and in situ data for 1998–2009. • Stratification from sea-ice melt resulted in largest CHL at the marginal ice zone. • Stratification caused by solar warming promoted open ocean blooms. • Late retreat of Svalbard shelf ice delayed coastal blooms.

Description: Marine sponges are generally classified as high microbial abundance (HMA) and low microbial abundance (LMA) species. Here, 16S rRNA amplicon sequencing was applied to investigate the diversity, specificity and transcriptional activity of microbes associated with an LMA sponge (Stylissa carteri), an HMA sponge (Xestospongia testudinaria) and sea water collected from the central Saudi Arabia coast of the Red Sea. Altogether, 887 068 denoised sequences were obtained, of which 806 661 sequences remained after quality control. This resulted in 1477 operational taxonomic units (OTUs) that were assigned to 27 microbial phyla. The microbial composition of S. carteri was more similar to that of sea water than to that of X. testudinaria, which is consistent with the observation that the sequence data set of S. carteri contained many more possibly sea water sequences (~24%) than the X. testudinaria data set (~6%). The most abundant OTUs were shared between all three sources (S. carteri, X. testudinaria, sea water), while rare OTUs were unique to any given source. Despite this high degree of overlap, each sponge species contained its own specific microbiota. The X. testudinaria-specific bacterial taxa were similar to those already described for this species. A set of S. carteri-specific bacterial taxa related to Proteobacteria and Nitrospira was identified, which are likely permanently associated with S. carteri. The transcriptional activity of sponge-associated microorganisms correlated well with their abundance. Quantitative PCR revealed the presence of Poribacteria, representing typical sponge symbionts, in both sponge species and in sea water; however, low transcriptional activity in sea water suggested that Poribacteria are not active outside the host context.

Description: Several slope failures are observed near the deformation front on the frontal ridges of the northern Cascadia accretionary margin off Vancouver Island. The cause for these events is not clear, although several lines of evidence indicate a possible connection between the occurrence of gas hydrate and submarine landslide features. The presence of gas hydrate is indicated by a prominent bottom-simulating reflector (BSR), at a depth of ∼265–275 m beneath the seafloor (mbsf), as interpreted from vertical-incidence and wide-angle seismic data beneath the ridge crests of the frontal ridges. For one slide, informally called Slipstream Slide, the velocity structure inferred from tomography analyses shows anomalous high velocities values of about 2.0 km s−1 at shallow depths of 100 mbsf. The estimated depth of the glide plane (100 ± 10 m) closely matches the depth of these shallow high velocities. In contrast, at a frontal ridge slide just to the northwest (informally called Orca Slide), the glide plane occurs at the same depth as the current BSR. Our new results indicate that the glide plane of the Slipstream slope failure is associated with the contrast between sediments strengthened by gas hydrate and overlying sediments where little or no hydrate is present. In contrast, the glide plane of Orca Slide is between sediment strengthened by hydrate underlain by sediments beneath the gas hydrate stability zone, possibly containing free gas. Additionally, a set of margin perpendicular normal faults are imaged from seafloor down to BSR depth at both frontal ridges. As inferred from the multibeam bathymetry, the estimated volume of the material lost during the slope failure at Slipstream Slide is about 0.33 km3, and ∼0.24 km3 of this volume is present as debris material on the ocean basin floor. The 20 per cent difference is likely due to more widely distributed fine sediments not easily detectable as bathymetric anomalies. These volume estimates on the Cascadia margin are approaching the mass failure volume for other slides that have generated large tsunamis—for example 1–3 km3 for a 1998 Papua New Guinea slide.

Description: Highlights • Gas hydrate reported from the Andaman Sea, India after coring and drilling. • Geothermal modeling of base of gas hydrate stability zone. • Gas hydrate stability thickness map of Andaman Sea. • Gas hydrate saturation using rock physics modeling. • Seismic attributes (i.e. reflection strength and instantaneous frequency etc.). Abstract Wide-spread bottom simulating reflectors (BSRs) are observed along available multichannel seismic profiles covering an area of about 290 km2 in the Andaman Sea. The seismic data shows that the BSR occurs at places where water depth exceeds 1000 m, and is identified by cross-cutting relationships with the dipping reflectors. The BSR that represents the base of gas hydrate stability field can be used to infer the gas hydrate stability thickness, which ranges between ∼518 m to ∼861 m depending on water depths. In situ measurement at site 17 during the Indian National Gas Hydrate Program (NGHP) Expedition-01 shows very low geothermal gradient 19 ± 2 °C/km. A conductive model was used to determine geothermal gradients from BSRs, which is calculated and varying between 10 °C/km to 40 °C/km. The low geothermal gradient is responsible for the deepest BSR or gas hydrate stability zone (GHSZ) in the Andaman region and in the world. The geothermal modeling shows a close match of the predicted base of the gas hydrate stability zone with the observed BSR depths.

Description: Sponges are important components of marine benthic environments and are associated with microbial symbionts that carry out ecologically relevant functions. Stylissa carteri is an abundant, low-microbial abundance species in the Red Sea. We aimed to achieve the functional and taxonomic characterization of the most actively expressed prokaryotic genes in S. carteri. Prokaryotic mRNA was enriched from sponge total RNA, sequenced using Illumina HiSeq technology and annotated using the metagenomics Rapid Annotation using Subsystem Technology (MG-RAST) pipeline. We detected high expression of archaeal ammonia oxidation and photosynthetic carbon fixation by members of the genus Synechococcus. Functions related to stress response and membrane transporters were among the most highly expressed by S. carteri symbionts. Unexpectedly, gene functions related to methylotrophy were highly expressed by gammaproteobacterial symbionts. The presence of seawater-derived microbes is indicated by the phylogenetic proximity of organic carbon transporters to orthologues of members from the SAR11 clade. In summary, we revealed the most expressed functions of the S. carteri-associated microbial community and linked them to the dominant taxonomic members of the microbiome. This work demonstrates the applicability of metatranscriptomics to explore poorly characterized symbiotic consortia and expands our knowledge of the ecologically relevant functions carried out by coral reef sponge symbionts.

Description: Monitoring of the water column in the vicinity of offshore Carbon Capture and Storage (CCS) sites is needed to ensure site integrity and to protect the surrounding marine ecosystem. In this regard, the use of continuous, autonomous systems is considered greatly advantageous due to the costs and limitations of periodic, ship-based sampling campaigns. While various geochemical monitoring tools have been developed their elevated costs and complexities mean that typically only one unit can be deployed at a time, yielding single point temporal data but no spatial data. To address this the authors have developed low-cost pCO2 sensors (GasPro-pCO2) that are small, robust, stable, and which have a low power consumption, characteristics which allow for the deployment of numerous units to monitor the spatial-temporal distribution of pCO2, temperature, and water pressure in surface water environments. The present article details the results of three field deployments at the natural, CO2-leaking site near Panarea, Island. While the first consisted of 6 probes placed on the sea floor for a 2.5 month period, the other two involved the deployment of 20 GasPro units along a transect through the water column in the vicinity of active CO2 seeps over 2 – 4 days. Results show both transport and mixing processes and highlight the dynamic nature of the leakage-induced marine geochemical anomalies. Implications for monitoring programs as well as potential impacts are discussed.

Description: Although CO2 capture and storage in deep, offshore reservoirs is a proven technology, as illustrated by over 15 years of operation of the Sleipner site in the Norwegian North Sea, potential leakage from such sites into the overlying water column remains a concern for some stakeholders. Therefore, we are obliged to carefully assess our ability to predict and monitor the migration, fate, and potential ecosystem impact of any leaked CO2. The release of bubbles from the sea floor, their upward movement, and their dissolution into the surrounding water controls the initial boundary conditions, and thus an understanding of the behavior of CO2 bubbles is critical to address such issues related to monitoring and risk assessment. The present study describes results from an in situ experiment conducted in 12 m deep marine water near the extinct volcanic island of Panarea (Italy). Bubbles of a controlled size were created using natural CO2 released from the sea floor, and their evolution during ascent in the water column was monitored via both video and chemical measurements. The obtained results were modelled and a good fit was obtained, showing the potential of the model as a predictive tool. These preliminary results and an assessment of the difficulties encountered are examined and will be used to improve experimental design for the subsequent phase of this research.

Description: Highlights • The complex geodynamic structure of the area is reflected in the wide range of compositions of the emitted fluids. • High salinity waters with hydrocarbon gases and a purely crustal He component were collected from deep wells. • Hyperalkaline waters with CH4- and H2-dominated gases are found in the ophiolite complex. • Shallow meteoric groundwaters in the southern part of the basin show a prevailing atmospheric component for dissolved gases. • A significant mantle component (He and C) is found in the dissolved gases of the northeastern sites. Abstract We investigated the geochemical features of the fluids circulating over the Amik Basin (SE Turkey–Syria border), which is crossed by the Northern extension of the DSF (Dead Sea Fault) and represents the boundary area of three tectonic plates (Anatolian, Arabian and African plates). We collected 34 water samples (thermal and cold from natural springs and boreholes) as well as 8 gas samples (bubbling and gas seepage) besides the gases dissolved in the sampled waters. The results show that the dissolved gas phase is a mixture of shallow (atmospheric) and deep components either of mantle and crustal origin. Coherently the sampled waters are variable mixtures of shallow and deep ground waters, the latter being characterised by higher salinity and longer residence times. The deep groundwaters (from boreholes deeper than 1000 m) have a CH4-dominated dissolved gas phase related to the presence of hydrocarbon reservoirs. The very unique tectonic setting of the area includes the presence of an ophiolitic block outcropping in the westernmost area on the African Plate, as well as basalts located to the North and East on the Arabic Plate. The diffuse presence of CO2-enriched gases, although diluted by the huge groundwater circulation, testifies a regional degassing activity. Fluids circulating over the ophiolitic block are marked by H2-dominated gases with abiogenic methane and high-pH waters. The measured 3He/4He isotopic ratios display contributions from both crustal and mantle-derived sources over both sides of the DSF. Although the serpentinization process is generally independent from mantle-type contribution, the recorded helium isotopic ratios highlight variable contents of mantle-derived fluids. Due to the absence of recent volcanism over the western side of the basin (African Plate), we argue that CO2-rich volatiles carrying mantle-type helium and enriched in heavy carbon, are degassed by deep-rooted regional faults rather than from volcanic sources.

Description: Highlights: • Cold-water coral mound formation is mainly influenced by the baffling of fine grained material within a coral framework. • Mass wasting appears to be an important mound progradation process. • Even heavily reworked sediments contain valuable information on the original mound aggradation processes. Abstract: An unconformity-bound glacial sequence (135 cm thick) of a coral-bearing sediment core collected from the flank of a cold-water coral mound in the Banda Mound Province off Mauritania was analysed. In order to study the relation between coral framework growth and its filling by hemipelagic sediments, U-series dates obtained from the cold-water coral species Lophelia pertusa were compared to 14C dates of planktonic foraminifera of the surrounding matrix sediments. The coral ages, ranging from 45.1 to 32.3 ka BP, exhibit no clear depositional trend, while on the other hand the 14C dates of the matrix sediment provide ages within a much narrower time window of 〈3000 yrs (34.6–31.8 cal ka BP), corresponding to the latest phase of the coral growth period. In addition, high-resolution computer tomography data revealed a subdivision of the investigated sediment package into three distinct parts, defined by the portion and fragmentation of corals and associated macrofauna as well as in the density of the matrix sediments. Grain size spectra obtained on the matrix sediments show a homogeneous pattern throughout the core sediment package, with minor variations. These features are interpreted as indicators of redeposition. Based on the observed structures and the dating results, the sediments were interpreted as deposits of a mass wasting event, namely a debris flow. During this event, the sediment unit must have been entirely mixed; resulting in averaging of the foraminifera ages from the whole unit and giving randomly distributed coral ages. In this context, for the first time mass wasting is proposed to be a substantial process of mound progradation by exporting material from the mound top to the flanks. Hence, it may not only be an erosional feature but also widening the base of the mound, thus allowing further vertical mound growth.

Description: Highlights: • Development/evaluation of a ‘needle trap device’ (NTD) method for the analysis of VOC in seawater. • First field application of the NTD method in a Norwegian Fjord during a CO2 enrichment study. • Identification and quantification of DMS, isoprene and α-pinene under various pCO2 levels. • In field NTD GC-MS and P&T GC-FPD method comparison for the DMS datasets (r2 = 0.8). Abstract: A novel analytical method using newly developed needle trap devices (NTDs) and a gas chromatograph–mass spectrometer (GC–MS) system was developed. It has been applied for the first time on seawater samples to quantify marine volatile organic compounds (VOCs) relevant to atmospheric chemistry and climate. By purging gases from small water volumes (10 ml) onto sealable NTDs and then desorbing them thermally within the GC injection port, an effective analysis of a wide range of VOCs (isoprene to α-pinene) was achieved within 23 min. Good repeatability (RSDs 〈 16 %), linearity (r2 = 0.96–0.99) and limits of detection in the range of pM were obtained for all examined compounds. Following laboratory validation, the NTD method was applied in a mesocosm field study in a Norwegian Fjord. Nine individual mesocosm ecosystems under different CO2 regimes were examined. Dimethyl sulfide (DMS), isoprene and monoterpenes were identified and quantified in mesocosm seawater. The DMS measurements are compared with parallel measurements provided by an independent P&T GC–FPD system showing good correlation, r2 = 0.8. Our study indicates that the NTD method can be used successfully in place of the traditionally used extraction techniques (P&T, SPME) in marine environments to extend the suite of species typically measured and improve detection limits.

Description: Kalsilite-bearing igneous rocks are extremely rare,most known examples are volcanic. The few previously recorded kalsilite-bearing plutonic rocks are all Phanerozoic and mostly limited to the small ultrapotassic massifs of the Baikal–Stanovoi Rift in the Siberian Craton, the Greenland Batbjerg Massif, and the Kola Peninsula Khibiny Complex. We have found that the Archean to Proterozoic transition in thewestern Reguibat Rise of theWest African Craton is marked by several small massifs predominantly composed of kalsilite syenites, i.e., synnyrites. The largest massif is Awsard, a deep-seated intrusive body mainly composed of 2.46 Ga synnyrites and K-rich nepheline syenites with mantle-like Sr and Nd (whole-rock) and O (zircon) isotope composition. Apart from some superficial resemblance to the Baikal–Stanovoi synnyritiferous complexes, Awsard has no known equivalent in the geological record. It is the oldest, the deepest and the largest known occurrence of synnyrites. Awsard comprises solely felsic syenites with εNd(t) notably more primitive than their Siberian counterparts. The synnyrites contain kalsilite and rare nepheline as primary phases with no leucite or leucite pseudomorphs. Kalsilite and nepheline form large discrete grains that, in places, are accompanied by spectacular Ks–Or or Ne–Or symplectites. The symplectites are magmatic, generated by simultaneous crystallization of the two phases and the imbalance between the growth rate of the feldspar and the diffusivity of silica and alkalis in the melt. To explain why Awsard lacks mafic rocks and associated carbonatites, typical of other synnyrite massifs, we propose that ascending water-poor (H2O b 0.65 wt.%) mafic ultrapotassic magmas solidified at a pressure of 10–16 kbar underneath the already stabilized Archean crust of the region. In these conditions leucite began to crystallize when the temperature dropped to around 1100 °C. As a result of their low density, leucite crystals floated and formed a cap at the top of the intrusion. Then, the chamber was replenished with awater-rich andmore sodic ultrapotassicmagma that originated in the samemetasomatized mantle-source region. After prolonged fractional crystallization this second magma released an aqueous vapor phase that migrated upwards and melted the leucite cap thus producing a low-density hydrous magma of leucite-like, synnyritic, composition. This leucite-like magma, and the late residual melts from the second pulse that replenished the chamber, ascended and intruded the already cratonized lower crust of the western Reguibat Rise. There, the magmas crystallized outside the leucite stability field to produce the synnyrites and the nepheline syenites, respectively. There is no evidence that the metasomatic refertilization of the mantle required to produce the initial ultrapotassic mafic magmas was related to subduction fluids. On the contrary, it seems to have been caused by incompatible-element enriched hydrous fluids released from delaminated lower crustal fragments.

Description: Increasingly large climate model simulations are enhancing our understanding of the processes and causes of anthropogenic climate change, thanks to very large public investments in high-performance computing at national and international institutions. Various climate models implement mathematical approximations of nature in different ways, which are often based on differing computational grids. These complex, parallelized coupled system codes combine numerous complex submodels (ocean, atmosphere, land, biosphere, sea ice, land ice, etc.) that represent components of the larger complex climate system.

Description: Yeasts and molds are important microorganisms related to human welfare, safety, and food resources. They contribute greatly to the food industry in areas such as winemaking, single-cell protein production, brewing, baking, vitamin production, etc. However, under certain conditions they can act as potential spoilage organisms in food, especially in processed, preserved, and refrigerated food. Enumeration and identification of yeasts and molds from foods are of great importance in understanding the value of these organisms in various food systems as well as their role in spoilage. Knowledge of how certain yeasts and molds colonize meat products and of their effects on the meat products is essential in order to prevent economic losses during spoilage or to maximize desirable fermentation of certain cured meat products by yeasts and molds. Occasionally, some pathogenic yeasts and molds might occur in meat and meat products that may pose food safety issues.

Description: Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records provide a master record of past climatic changes throughout the Last InterglacialeGlacial cycle in the North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial records) project, protocols have been proposed to ensure consistent and robust correlation between different records of past climate. A key element of these protocols has been the formal definition and ordinal numbering of the sequence of Greenland Stadials (GS) and Greenland Interstadials (GI) within the most recent glacial period. The GS and GI periods are the Greenland expressions of the characteristic DansgaardeOeschger events that represent cold and warm phases of the North Atlantic region, respectively. We present here a more detailed and extended GS/GI template for the whole of the Last Glacial period. It is based on a synchronization of the NGRIP, GRIP, and GISP2 ice-core records that allows the parallel analysis of all three records on a common time scale. The boundaries of the GS and GI periods are defined based on a combination of stable-oxygen isotope ratios of the ice (d18O, reflecting mainly local temperature) and calcium ion concentrations (reflecting mainly atmospheric dust loading) measured in the ice. The data not only resolve the well-known sequence of DansgaardeOeschger events that were first defined and numbered in the ice-core records more than two decades ago, but also better resolve a number of short-lived climatic oscillations, some defined here for the first time. Using this revised scheme, we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the Last Glacial period that are represented in the Greenland ice records. The final product constitutes an extended and better resolved Greenland stratotype sequence, against which other proxy records can be compared and correlated. It also provides a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations.

Description: Highlights: • Noelaerhabdaceae mean coccolith weight increases during Termination II. • Coccolith assemblage and the degree of coccolith calcification control mean weight. • Causes for the weight increase are different in sub-arctic and tropical settings. • Terminations I and II show opposite patterns in coccolith weight changes. • Rising CO2 during deglaciations has no uniform effect on coccolith weight. Abstract: Glacial to interglacial environmental changes have a strong impact on coccolithophore assemblage composition. At the same time, glacial terminations are characterised by an increase in atmospheric CO2 concentration. In order to determine how these two processes influence the calcite production of coccolithophores, we compared coccolith weight estimates obtained with the automated coccolith recognition system SYRACO with SEM assemblage counts covering the penultimate glacial Termination (T II) from two sediment cores in the North Atlantic Ocean. At the temperate Rockall Plateau (ODP Site 980), mean coccolith weight peaks around Heinrich event 11. This is paralleled by a shift within the coccolith assemblage related to the changes of the oceanic frontal system during Termination II. In the tropical Florida Strait, far from the influences of frontal zones, mean Noelaerhabdaceae coccolith weight doubles during Termination II. This is partly due to an assemblage shift towards larger and heavier calcifying morphotypes, but mainly an effect of increasing coccolithophore calcification. This increase is exactly mirroring the rise in atmospheric CO2, contradicting previous findings from Termination I. Reconstructions of DIC, alkalinity and calcite saturation at the Florida Strait during Termination II produce higher estimates of these parameters compared to previous studies for which coccolith weight estimates are available, and therefore a change of the carbonate system is the most likely cause for the coccolithophore calcification increase during atmospheric CO2 rise. Our results illustrate that even during rising atmospheric CO2 the conditions of the seawater carbonate system can be favourable for coccolithophore calcification. The total CaCO3 production of a coccolithophore assemblage under increasing CO2 therefore depends on regional seawater carbonate system characteristics and the local assemblage composition.

Description: Glacial environments may provide an important but poorly constrained source of potentially bioavailable iron and manganese phases to the coastal ocean in high-latitude regions. Little is known about the fate and biogeochemical cycling of glacially derived iron and manganese in the coastal marine realm. Sediment and porewater samples were collected along transects from the fjord mouths to the tidewater glaciers at the fjord heads in Smeerenburgfjorden, Kongsfjorden, and Van Keulenfjorden along Western Svalbard. Solid-phase iron and manganese speciation, determined by sequential chemical extraction, could be linked to the compositions of the local bedrock and hydrological/weathering conditions below the local glaciers. The concentration and sulfur isotope composition of chromium reducible sulfur (CRS) in Kongs- and Van Keulenfjorden sediments largely reflect the delivery rate and isotope composition of detrital pyrite originating from adjacent glaciers. The varying input of reducible iron and manganese oxide phases and the input of organic matter of varying reactivity control the pathways of organic carbon mineralization in the sediments of the three fjords. High reducible iron and manganese oxide concentrations and elevated metal accumulation rates coupled to low input of “fresh” organic matter lead to a strong expression of dissimilatory metal oxide reduction evidenced in very high porewater iron (up to 800 lM) and manganese (up to 210 lM) concentrations in Kongsfjorden and Van Keulenfjorden. Sediment reworking by the benthic macrofauna and physical sediment resuspension via iceberg calving may be additional factors that promote extensive benthic iron and manganese cycling in these fjords. On-going benthic recycling of glacially derived dissolved iron into overlying seawater, where partial reoxidation and deposition occurs, facilitates the transport of iron across the fjords and potentially into adjacent continental shelf waters. Such iron-dominated fjord sediments are likely to provide significant fluxes of potentially bioavailable iron to coastal waters and beyond. By contrast, low delivery of reducible iron (oxyhydr)oxide phases and elevated organic carbon mineralization rates driven by elevated input of “fresh” marine organic matter allow organoclastic sulfate reduction to dominate carbon remineralization at the outer Smeerenburgfjorden sites, which may limit iron fluxes to the water column.

Description: Highlights: • Geochemical data from high-T leucogranites imply pure crustal melting. • New U–Pb monazite ages constrain intrusion time close to peak metamorphism. • Updated Sr–Nd–Pb isotope data imply metasedimentary sources. Two suites of leucogranites were emplaced at 508 ± 5.9 Ma in the Okombahe District of the Damara belt (Namibia) synchronous with the peak of regional high-temperature metamorphism. The Sr (87Sr/86Srinit: 0.707 to 0.711), Nd (εNdinit: − 4.5 to − 6.6), and Pb isotopic (206Pb/204Pb: 18.51–19.13; 207Pb/204Pb: 15.63–15.69; 208Pb/204Pb: 38.08–38.66) compositions indicate that these peraluminous S-type granites were derived from mid- to lower-crustal rocks, which are slightly different to the metapelitic rocks into which they intruded. Since the leucogranites are unfractionated and show no evidence for assimilation or contamination, they constrain the temperature and pressure conditions of their formation. Calculated Zr and LREE saturation temperatures of ca. 850 °C indicate high-temperature crustal melts. High Rb/Sr and low Sr/Ba ratios are consistent with biotite dehydration melting of pelitic source rocks. Qz–Ab–Or systematics reveal that melting and segregation for the least fractionated samples occurred at ca. 7 kbar corresponding to a mid-crustal level of ca. 26 km. However, there is no evidence for a mantle component that could have served as a local heat source for crustal melting. Therefore, the hot felsic magmas that formed close to the time of peak metamorphism are the result of long-lasting high temperature regional metamorphic conditions and intra-crustal collision.

Description: Highlights: • Marie Byrd Seamounts (MBS) formed off Antarctica at 65-56 Ma in an extensional regime • MBS originate from HIMU-type mantle attached at the base of the Antarctic lithosphere • Continental insulation flow transferred HIMU mantle into the oceanic mantle New radiometric age and geochemical data of volcanic rocks from the guyot-type Marie Byrd Seamounts (MBS) and the De Gerlache Seamounts and Peter I Island (Amundsen Sea) are presented. 40Ar/39Ar ages of the shield phase of three MBS are Early Cenozoic (65 to 56 Ma) and indicate formation well after creation of the Pacific-Antarctic Ridge. A Pliocene age (3.0 Ma) documents a younger phase of volcanism at one MBS and a Pleistocene age (1.8 Ma) for the submarine base of Peter I Island. Together with published data, the new age data imply that Cenozoic intraplate magmatism occurred at distinct time intervals in spatially confined areas of the Amundsen Sea, excluding an origin through a fixed mantle plume. Peter I Island appears strongly influenced by an EMII type mantle component that may reflect shallow mantle recycling of a continental raft during the final breakup of Gondwana. By contrast the Sr-Nd-Pb-Hf isotopic compositions of the MBS display a strong affinity to a HIMU type mantle source. On a regional scale the isotopic signatures overlap with those from volcanics related to the West Antarctic Rift System, and Cretaceous intraplate volcanics in and off New Zealand. We propose reactivation of the HIMU material, initially accreted to the base of continental lithosphere during the pre-rifting stage of Marie Byrd Land/Zealandia to explain intraplate volcanism in the Amundsen Sea in the absence of a long-lived hotspot. We propose continental insulation flow as the most plausible mechanism to transfer the sub-continental accreted plume material into the shallow oceanic mantle. Crustal extension at the southern boundary of the Bellingshausen Plate from about 74 to 62 Ma may have triggered adiabatic rise of the HIMU material from the base of Marie Byrd Land to form the MBS. The De Gerlache Seamounts are most likely related to a preserved zone of lithospheric weakness underneath the De Gerlache Gravity Anomaly.

Description: Global warming is assumed to alter the trophic interactions and carbon flow patterns of aquatic food webs. The impact of temperature on phyto-bacterioplankton coupling and bacterial community composition (BCC) was the focus of the present study, in which an indoor mesocosm experiment with natural plankton communities from the western Baltic Sea was conducted. A 6°C increase in water temperature resulted, as predicted, in tighter coupling between the diatom-dominated phytoplankton and heterotrophic bacteria, accompanied by a strong increase in carbon flow into bacterioplankton during the phytoplankton bloom phase. Suppressed bacterial development at cold in situ temperatures probably reflected lowered bacterial production and grazing by protists, as the latter were less affected by low temperatures. BCC was strongly influenced by the phytoplankton bloom stage and to a lesser extent by temperature. Under both temperature regimes, Gammaproteobacteria clearly dominated during the phytoplankton peak, with Glaciecola sp. as the single most abundant taxon. However, warming induced the appearance of additional bacterial taxa belonging to Betaproteobacteria and Bacteroidetes. Our results show that warming during an early phytoplankton bloom causes a shift towards a more heterotrophic system, with the appearance of new bacterial taxa suggesting a potential for utilization of a broader substrate spectrum.

Description: Highlights: • We used indoor mesocosms to test the impact of warming on plankton communities. • Different stages of phytoplankton bloom were analysed. • Increased temperature and zooplankton grazing had similar effects on phytoplankton. • Warming and increased zooplankton density decreased phytoplankton richness. • Warming and increased zooplankton density increased phytoplankton evenness. Recent climate warming is expected to affect phytoplankton biomass and diversity in marine ecosystems. Temperature can act directly on phytoplankton (e.g. rendering physiological processes) or indirectly due to changes in zooplankton grazing activity. We tested experimentally the impact of increased temperature on natural phytoplankton and zooplankton communities using indoor mesocosms and combined the results from different experimental years applying a meta-analytic approach. We divided our analysis into three bloom phases to define the strength of temperature and zooplankton impacts on phytoplankton in different stages of bloom development. Within the constraints of an experiment, our results suggest that increased temperature and zooplankton grazing have similar effects on phytoplankton diversity, which are most apparent in the post-bloom phase, when zooplankton abundances reach the highest values. Moreover, we observed changes in zooplankton composition in response to warming and initial conditions, which can additionally affect phytoplankton diversity, because changing feeding preferences of zooplankton can affect phytoplankton community structure. We conclude that phytoplankton diversity is indirectly affected by temperature in the post-bloom phase through changing zooplankton composition and grazing activities. Before and during the bloom, however, these effects seem to be overruled by temperature enhanced bottom-up processes such as phytoplankton nutrient uptake.

Description: We present an unprecedented multicentennial sediment record from the foot of Vesterisbanken Seamount, central Greenland Sea, covering the past 22.3 thousand years (ka). Based on planktic foraminiferal total abundances, species assemblages, and stable oxygen and carbon isotopes, the palaeoenvironments in this region of modern deepwater renewal were reconstructed. Results show that during the Last Glacial Maximum the area was affected by harsh polar conditions with only episodic improvements during warm summer seasons. Since 18 ka extreme freshwater discharges from nearby sources occurred, influencing the surface water environment. The last major freshwater event took place during the Younger Dryas. The onset of the Holocene was characterized by an improvement of environmental conditions suggesting warming and increasing ventilation of the upper water layers. The early Holocene saw a stronger Atlantic waters advection to the area, which began around 10.5 and ended quite rapidly at 5.5 ka, followed by the onset of Neoglacial cooling. Surface water ventilation reached a maximum in the middle Holocene. Around 3 ka the surface water stratification increased leading to subsequent amplification of the warming induced the North Atlantic Oscillation at 2 ka.

Description: I summarize marine studies on plastic versus adaptive responses to global change. Due to the lack of time series, this review focuses largely on the potential for adaptive evolution in marine animals and plants. The approaches were mainly synchronic comparisons of phenotypically divergent populations, substituting spatial contrasts in temperature or CO2 environments for temporal changes, or in assessments of adaptive genetic diversity within populations for traits important under global change. The available literature is biased towards gastropods, crustaceans, cnidarians and macroalgae. Focal traits were mostly environmental tolerances, which correspond to phenotypic buffering, a plasticity type that maintains a functional phenotype despite external disturbance. Almost all studies address coastal species that are already today exposed to fluctuations in temperature, pH and oxygen levels. Recommendations for future research include (i) initiation and analyses of observational and experimental temporal studies encompassing diverse phenotypic traits (including diapausing cues, dispersal traits, reproductive timing, morphology) (ii) quantification of nongenetic trans-generational effects along with components of additive genetic variance (iii) adaptive changes in microbe–host associations under the holobiont model in response to global change (iv) evolution of plasticity patterns under increasingly fluctuating environments and extreme conditions and (v) joint consideration of demography and evolutionary adaptation in evolutionary rescue approaches.

Description: Highlights: • Phase II of the Coordinated Ocean-ice Reference Experiments (CORE-II) is introduced. • Solutions from CORE-II simulations from eighteen participating models are presented. • Mean states in the North Atlantic with a focus on AMOC are examined. • The North Atlantic solutions differ substantially among the models. • Many factors, including parameterization choices, contribute to these differences. Simulation characteristics from eighteen global ocean–sea-ice coupled models are presented with a focus on the mean Atlantic meridional overturning circulation (AMOC) and other related fields in the North Atlantic. These experiments use inter-annually varying atmospheric forcing data sets for the 60-year period from 1948 to 2007 and are performed as contributions to the second phase of the Coordinated Ocean-ice Reference Experiments (CORE-II). The protocol for conducting such CORE-II experiments is summarized. Despite using the same atmospheric forcing, the solutions show significant differences. As most models also differ from available observations, biases in the Labrador Sea region in upper-ocean potential temperature and salinity distributions, mixed layer depths, and sea-ice cover are identified as contributors to differences in AMOC. These differences in the solutions do not suggest an obvious grouping of the models based on their ocean model lineage, their vertical coordinate representations, or surface salinity restoring strengths. Thus, the solution differences among the models are attributed primarily to use of different subgrid scale parameterizations and parameter choices as well as to differences in vertical and horizontal grid resolutions in the ocean models. Use of a wide variety of sea-ice models with diverse snow and sea-ice albedo treatments also contributes to these differences. Based on the diagnostics considered, the majority of the models appear suitable for use in studies involving the North Atlantic, but some models require dedicated development effort.

Description: The western Woodlark Basin lies within a gold-rich metallogenic province. This area is characterized by detachment faults that record ongoing extension and act as major pathways for the circulation of hydrothermal fluids. Dredging from the flanks of a submarine ridge southeast of Cheshire Seamount, western Woodlark Basin retrieved hydrothermally altered monomictic to polymictic crackle, mosaic and chaotic breccias with at least 30% clasts N2 mmin diameter. The precursor rocks are andesitic to rhyolitic in composition, but have been intensely hydrothermally altered, with about 90% of the volcanic glass replaced by secondaryminerals. The breccias show five generations of quartz growth, with the first being related to magmatic processes and the remaining four to alteration stages including silicification, chloritization, illitization, sericitization, albitization, and sulfidation. Needle-like crystals ofmordenite (zeolite)withmultiple growth centers growon the fourth generation of quartz. Notable textural variants in the breccias are vesicles, perlitic cracks, and zoned alteration halos that mantle the rims of clasts. Electron microprobe analyses on chlorite from breccia samples have identified clinochlore as the main chlorite type and indicate a formation temperature in the range of 210–304 °C. This and the elevated Au–As–Ag–Hg–Zn–Pb–Sb contents of a mineralized sample indicate hydrothermal alteration temperatures N200 °C suggesting that these breccias may represent the upflow zone of a hydrothermal system and highlight the potential for seafloor massive sulfides in the area. The breccias show elevated contents of immobile trace elements and LREE as well as a depletion in Ta and Nb suggesting that the precursor rocks were formed in a rift-related suprasubduction environment.

Description: Highlights: • We combine high-resolution ocean models with population genetics • Variation in wind-driven ocean currents mediates the collapse of A. anguilla • Female eels are philopatric within the Sargasso Sea, while males maintain gene flow • We present first evidence of the role of ocean currents in shaping species’ evolution Summary: Worldwide, exploited marine fish stocks are under threat of collapse [1]. Although the drivers behind such collapses are diverse, it is becoming evident that failure to consider evolutionary processes in fisheries management can have drastic consequences on a species’ long-term viability [2]. The European eel (Anguilla anguilla; Linnaeus, 1758) is no exception: not only does the steep decline in recruitment observed in the 1980s [ 3 and 4] remain largely unexplained, the punctual detection of genetic structure also raises questions regarding the existence of a single panmictic population [ 5, 6 and 7]. With its extended Transatlantic dispersal, pinpointing the role of ocean dynamics is crucial to understand both the population structure and the widespread decline of this species. Hence, we combined dispersal simulations using a half century of high-resolution ocean model data with population genetics tools. We show that regional atmospherically driven ocean current variations in the Sargasso Sea were the major driver of the onset of the sharp decline in eel recruitment in the beginning of the 1980s. The simulations combined with genotyping of natural coastal eel populations furthermore suggest that unexpected evidence of coastal genetic differentiation is consistent with cryptic female philopatric behavior within the Sargasso Sea. Such results demonstrate the key constraint of the variable oceanic environment on the European eel population.

Description: Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (~ 400, 1000 and 3000 μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO2 due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO2 fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20 weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO2, regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO2 in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO2, irrespective of parental treatment. In contrast, elevated pCO2 had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO2 over 5 weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO2 negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO2 in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried-over from adults to their offspring. Our findings indicate that populations from fluctuating pCO2 environments are more tolerant to elevated pCO2 than populations from more stable pCO2 habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO2 stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus

Description: The Atlantis II Deep is a brine-filled depression on the slowly spreading Red Sea rift axis. It is by far the largest deposit of hydrothermally precipitated metals on the present ocean floor and the only known modern deposit that is analogous to laminated Fe-rich chemical sediments, such as banded iron formation (BIF). The brine pool at the bottom of the Atlantis II Deep creates an environment where most of the hydrothermally sourced elements can be dispersed and deposited over an area of ∼60 km2. We analyzed the rare earth element concentrations in 100 small-volume samples from 9 cores in different parts of the Atlantis II Deep to better understand the origins of different types of metalliferous sediments (detrital, proximal hydrothermal and distal hydrothermal). Our results agree with earlier studies based on larger bulk samples that show the composition of the major depositional units is related to major changes in the location and intensity of hydrothermal activity and the amount of hydrothermal versus background sedimentation. In this paper, we address the origins of chemically distinct laminae (down to sub-millimeter) that correspond to ∼annual deposition. REE patterns clearly reflect 3 different sources (e.g., detrital, scavenging, direct hydrothermal input). Detrital REE that are delivered to the Deep from outside account for most of the REE in the sediments of the Atlantis II Deep, similar to BIF, and are unaffected by fractionation due to hydrothermal processes during deposition and diagenesis. Fe- and Mn-(oxy)hydroxides that form at the anoxic–oxic boundary scavenge REE from the brine pool as they settle. The Fe-(oxy)hydroxides contain a larger proportion of REE from seawater than any other sediment-type and also scavenge REE from pore waters after deposition. In contrast, the Mn-(oxy)hydroxides dissolve before deposition and thus function as transporting agents between seawater and the brine. However, there is little evidence for direct seawater influence in the REE geochemistry of the sediments (e.g., Y/Ho ratio). Non-ferrous sulfides form proximal to the hydrothermal vent source and inherit an hydrothermal REE pattern. The total REE content of the presently forming Fe-(oxy)hydroxides is very low due to limited input of REE into the brine. The largest proportion of non-detrital REE appears to have been deposited early in the history of the basin from an initial brine pool that was relatively enriched in REE, followed by a change in REE chemistry in later sediments. Similar abrupt changes in the REE chemistry of ancient chemical sediments may record similar processes, including changes in local basin evolution and input of REE from different sources.

Description: Highlights: • A full-scale 5 year experimental study of ecosystem responses to increased nutrients. • Concentrations of DIN and DIP did not respond positively to increased nutrient input. • Concentrations of PON and POP and phytoplankton biomass responded positively. • PON is suggested as credible indicator for chemical and ecological state. • A general scientific concept for managing nutrient input to coastal waters is presented. Abstract: The objective of this study was to quantify chemical and biological responses to an experimentally increased nutrient input to an open coastal planktonic ecosystem and to contribute to a scientific concept and credible indicators for managing nutrient supply to coastal waters. Data were derived in a 5 year fertilisation experiment of a tidal driven coastal lagoon at the outer coast off Central Norway (63°36’ N, 9°33’ E), with a surface area of 275.000 m2, volume of 5.5 mill m3, mean depth of 22 m and a water exchange rate of 0.19 day- 1. The lagoon was fertilised in the summer season 1998 and 1999, while summer seasons 1996-97 and 2000 and inflowing water were used as unfertilised references. Most measured chemical and biological variables showed linear responses with an increasing loading rate of inorganic N and P (LN and LP, respectively). PON, POP and POC (〈 200 μm) responded significantly (P 〈 0.05) as did chlorophyll a and phytoplankton C. DIN and DIP remained, however, constant and independent of LN and LP, respectively (P 〉 0.05) as did heterotrophic biomass (P 〉 0.05). We evaluate the response variables assuming a stepwise incorporation process of nutrients in the planktonic ecosystem and how that will interact with biological response times and water dilution rates. We suggest that PON is a credible indicator of both chemical and ecological states of the planktonic ecosystem and that natural background and upper critical concentrations are 46 and 88 mg PON m- 3, respectively. The study was supported by data from mesocosms. We discuss the scientific relevance of our suggestions, how results can be extrapolated to a broader geographical scale, and we propose a science-based concept for the management of nutrient emission to open coastal waters.

Description: Dissolved rare earth element (REE) concentrations and Nd isotope compositions were measured for surface waters and full water column profiles of the Gulf of Alaska (GoA), and compared to water mass properties and circulation in order to better understand the mechanisms controlling the input and transport of REEs in the ocean. The REEs display a typical open-ocean range of concentrations (i.e., La: 12-66 pM; Lu: 0.2-2.5 pM) and depth distributions (i.e., surface ocean depletion and enrichment with water depth). Nd isotope signatures are highly radiogenic, as expected for the North Pacific margin (ranging from -3.8 to +0.2 epsilon Nd). The most radiogenic values were found in the coastal waters but also in the cores of eddies, indicating efficient export of REEs from the margins and across the mixed layer. This is the first time that distinct Nd isotope distributions in near surface waters can be directly assigned to offshore eddy transport. A distinct mid-depth (similar to 2200 m) Nd isotope signal was found that most likely reflects advection of a water mass that formed through past down-welling in the Northern Pacific. Subsurface Nd isotope compositions appear to behave conservatively and can be explained through a REE distribution model proposed here. This model is based on multivariate analysis of the REEs and invokes two distinct "pools" of dissolved REEs: a "passive pool" complexed by carbonate ions, and a "bio-reactive pool" that is microbially manipulated. The latter "pool" is only significant in the upper water column and most likely reflects the indirect effects of microbial cycling of iron. Our model of the open ocean REE distribution contributes to explaining the conservative nature of Nd isotopes and provides a mechanism linking surface ocean and pore water REE dynamics

Description: Highlights: • The bioactive potential of primary metabolites from marine mussels is reviewed. • The focus is on proteins, lipids, and carbohydrates from Mytilus and Perna species. • Commercially available dietary mussel oil supplements are discussed. • Information on purification techniques for metabolites of interest is provided. • An overview on harmful mussel biotoxins produced by microalgae is given. The consumption of marine mussels as popular seafood has increased steadily over the past decades. Awareness of mussel derived molecules, that promote health, has contributed to extensive research efforts in that field. This review highlights the bioactive potential of mussel components from species of the genus Mytilus (e.g. M. edulis) and Perna (e.g. P. canaliculus). In particular, the bioactivity related to three major chemical classes of mussel primary metabolites, i.e. proteins, lipids, and carbohydrates, is evaluated. Within the group of proteins the focus is mainly on mussel peptides e.g. those obtained by bio-transformation processes, such as fermentation. In addition, mussel lipids, comprising polyunsaturated fatty acids (PUFAs), are discussed as compounds that are well known for prevention and treatment of rheumatoid arthritis (RA). Within the third group of carbohydrates, mussel polysaccharides are investigated. Furthermore, the importance of monitoring the mussel as food material in respect to contaminations with natural toxins produced by microalgae is discussed.

Description: Highlights • High-resolution AUV bathymetry is used to identify hydrothermal sulfides on the seafloor. • 1.2 Mt of massive sulfide is identified along 24 km of mid-ocean ridge length. • Massive sulfide accumulated at a rate of ∼400 t/yr. • Efficiency of sulfide deposition is ∼5% of total mobilized metals and reduced sulfur. • Current global seafloor sulfide estimates likely underestimate amount present by about a factor of four. Abstract Hydrothermal sulfide deposits that form on the seafloor are often located by the detection of hydrothermal plumes in the water column, followed by exploration with deep-towed cameras, side-scan sonar imaging, and finally by visual surveys using remotely-operated vehicle or occupied submersible. Hydrothermal plume detection, however, is ineffective for finding hydrothermally-inactive sulfide deposits, which may represent a significant amount of the total sulfide accumulation on the seafloor, even in hydrothermally active settings. Here, we present results from recent high-resolution, autonomous underwater vehicle-based mapping of the hydrothermally-active Endeavour Segment of the Juan de Fuca Ridge, in the Northeast Pacific Ocean. Analysis of the ridge bathymetry resulted in the location of 581 individual sulfide deposits along 24 km of ridge length. Hydrothermal deposits were distinguished from volcanic and tectonic features based on the characteristics of their surface morphology, such as shape and slope angles. Volume calculations for each deposit results in a total volume of 372,500 m3 of hydrothermal sulfide–sulfate–silica material, for an equivalent mass of ∼1.2 Mt of hydrothermal material on the seafloor within the ridge's axial valley, assuming a density of 3.1 g/cm3. Much of this total volume is from previously undocumented inactive deposits outside the main active vent fields. Based on minimum ages of sulfide deposition, the deposits accumulated at a maximum rate of ∼400 t/yr, with a depositional efficiency (proportion of hydrothermal material that accumulates on the seafloor to the total amount hydrothermally mobilized and transported to the seafloor) of ∼5%. The calculated sulfide tonnage represents a four-fold increase over previous sulfide estimates for the Endeavour Segment that were based largely on accumulations from within the active fields. These results suggest that recent global seafloor sulfide resource estimates, which were based mostly on the sizes and distribution of hydrothermally-active deposits, may be similarly underestimating the amount of sulfide along the global submarine neovolcanic zones.

Description: The potential for a dynamical impact of Saharan mineral dust on the North Atlantic Ocean large-scale circulation is investigated. To this end, an ocean general circulation model forced by atmospheric fluxes is perturbed by an idealized, seasonally varying, net shortwave flux anomaly, as it results from remote sensing observations of aerosol optical thickness representing Saharan dust load in the atmosphere. The dust dynamical impact on the circulation is assessed through a comparison between perturbed and an unperturbed run. Results suggest that, following the dust-induced shortwave irradiance anomaly, a buoyancy anomaly is created in the Atlantic offshore the African coast, which over the course of the time propagates westward into the interior Atlantic while progressively subducting. Changes in the large-scale barotropic and overturning circulations are significant after 3 years, which coincides with the elapsed time required by the bulk of the buoyancy perturbation to reach the western boundary of the North Atlantic. Although small in amplitude, the changes in the meridional overturning are of the same order as interannual-to-decadal variability. Variations in the amplitude of the forcing lead to changes in the amplitude of the response, which is almost linear during the first 3 years. In addition, a fast, but dynamically insignificant, response can be observed to propagate poleward along the eastern boundary of the North Atlantic, which contributes to a nonlinear response in the subpolar region north of 40°N.

Description: Dinoflagellate blooms of the genus Dinophysis occur regularly in the coastal Arabian Sea. By producing toxins, which may accumulate in marine bivalves, they impose threat to human health. Using time-series data on environmental variables (e.g., nutrients, sea surface temperature and salinity) and concurrent Dinophysis abundances for the surface waters along the coast of the southeastern Arabian Sea during the period 1990–2010, we investigate whether potential climate change signals play a role in driving blooms of Dinophysis spp. A logistic Generalized Linear Model was adopted to test the effect of environmental variables on Dinophysis abundances over a range of threshold values (102–105 cells m−3) for blooms. Some of the extreme events occurred during the pre-monsoon (March–May) periods. Model validation suggested a threshold of 105 cells m−3 to be better than other thresholds in examining the Dinophysis abundances, and the variation in this threshold is explained by sea surface temperature, salinity, dissolved inorganic nitrogen to phosphorus ratio and total suspended solids (turbidity). Fate of the Dinophysis blooms in the coastal Arabian Sea for different climate change scenarios is discussed.

Description: Three species of marine phytoplankton, Rhodomonas sp., Isochrysis galbana Parke, and Phaeodactylum tricornutum Bohlin, were cultivated in semicontinuous cultures to test biochemical responses (fatty acids; FAs) to five nitrogen (N):phosphorus (P) supply ratios and four growth rates (dilution rates). The characteristic FA profile was observed for each algal species (representing particular algal class), which remained relatively stable across the entire ranges of N:P supply ratios and growth rates. For all species, significant direct effects of N:P supply ratios on FAs were found at lower growth rates. The highest saturated and monounsaturated fatty acid (SFA and MUFA) contents were observed under N deficiency at the lowest growth rate in all three species, while responses of polyunsaturated fatty acids (PUFAs) revealed no consistent pattern. Total FAs (and SFAs and MUFAs) in all species showed significant negative correlations with N cell quota (QN) under N deficiency, but PUFAs had species-specific correlations with QN. The results show that characteristic FA profiles of algal genus or species (representing particular algal classes) underlie fluctuations according to culture conditions. The significant correlation between FAs and QN under N deficiency suggests that elemental and biochemical limitation of phytoplankton should be considered mutually as determinants of food quality for zooplankton in marine ecosystems.

Description: Atlantic multidecadal variability (AMV) is known to impact climate globally, and knowledge about the persistence of AMV is important for understanding past and future climate variability, as well as modeling and assessing climate impacts. The short observational data do not significantly resolve multidecadal variability, but recent paleoproxy reconstructions show multidecadal variability in North Atlantic temperature prior to the instrumental record. However, most of these reconstructions are land-based, not necessarily representing sea surface temperature. Proxy records are also subject to dating errors and microenvironmental effects. We extend the record of AMV 90 years past the instrumental record using principle component analysis of five marine-based proxy records to identify the leading mode of variability. The first principal component is consistent with the observed AMV, and multidecadal variability seems to persist prior to the instrumental record. Thus, we demonstrate that reconstructions of past Atlantic low-frequency variability can be improved by combining marine-based proxies.

Description: Ocean warming has been implicated in the observed decline of oceanic phytoplankton biomass. Some studies suggest a physical pathway of warming via stratification and nutrient flux, and others a biological effect on plankton metabolic rates; yet the relative strength and possible interaction of these mechanisms remains unknown. Here, we implement projections from a global circulation model in a mesocosm experiment to examine both mechanisms in a multi-trophic plankton community. Warming treatments had positive direct effects on phytoplankton biomass, but these were overcompensated by the negative effects of decreased nutrient flux. Zooplankton switched from phytoplankton to grazing on ciliates. These results contrast with previous experiments under nutrient-replete conditions, where warming indirectly reduced phytoplankton biomass via increased zooplankton grazing. We conclude that the effect of ocean warming on marine plankton depends on the nutrient regime, and provide a mechanistic basis for understanding global change in marine ecosystems.

Description: We present sedimentary geochemical data and in situ benthic flux measurements of dissolved inorganic nitrogen (DIN: NO3−, NO2−, NH4+) and oxygen (O2) from 7 sites with variable sand content along 18°N offshore Mauritania (NW Africa). Bottom water O2 concentrations at the shallowest station were hypoxic (42 μM) and increased to 125 μM at the deepest site (1113 m). Total oxygen uptake rates were highest on the shelf (−10.3 mmol O2 m−2 d−1) and decreased quasi-exponentially with water depth to −3.2 mmol O2 m−2 d−1. Average denitrification rates estimated from a flux balance decreased with water depth from 2.2 to 0.2 mmol N m−2 d−1. Overall, the sediments acted as net sink for DIN. Observed increases in δ15NNO3 and δ18ONO3 in the benthic chamber deployed on the shelf, characterized by muddy sand, were used to calculate apparent benthic nitrate fractionation factors of 8.0‰ (15εapp) and 14.1‰ (18εapp). Measurements of δ15NNO2 further demonstrated that the sediments acted as a source of 15N depleted NO2−. These observations were analyzed using an isotope box model that considered denitrification and nitrification of NH4+ and NO2−. The principal findings were that (i) net benthic 14N/15N fractionation (εDEN) was 12.9 ± 1.7‰, (ii) inverse fractionation during nitrite oxidation leads to an efflux of isotopically light NO2− (−22 ± 1.9‰), and (iii) direct coupling between nitrification and denitrification in the sediment is negligible. Previously reported εDEN for fine-grained sediments are much lower (4–8‰). We speculate that high benthic nitrate fractionation is driven by a combination of enhanced porewater–seawater exchange in permeable sediments and the hypoxic, high productivity environment. Although not without uncertainties, the results presented could have important implications for understanding the current state of the marine N cycle.

Description: Higher latitude oceanic and climatic reconstructions are needed to distinguish natural climate variability from anthropogenic warming in regions projected to experience significant increases in temperature during this century. Clathromorphum nereostra turn is a long-lived coralline alga abundant along the Aleutian archipelago that records seasonal to centennial fluctuations in seawater temperatures in its high-Mg calcite skeleton. Thus, C. nereostratum is an important proxy archive to reconstruct past seawater temperature variability in this data-poor subarctic region. Here, we measured magnesium to calcium ratios (Mg/Ca) by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) along the growth axis in six live-collected specimens from three islands in the Aleutian archipelago to assess Mg/Ca reproducibility and to calibrate algal Mg/Ca against modern gridded sea surface temperature (SST) data products. The master Mg/Ca SST transfer function, determined by averaging the algal Mg/Ca SST from each island (n = 6), resulted in a reconstruction error of +/-0.45 degrees C, a 31-46% reduction in error compared to the reconstruction error for a single alga. The master algal-SST record interpolated to monthly and annual resolution significantly varied with gridded SST data products (r(2) = 0.98, p 〈 0.0001, n = 517 and r(2) = .27, p 〈 0.0003, n = 44, respectively) for the period from 1960 to 2003. Therefore, coralline algal Mg/Ca-derived SST reconstructions record absolute changes in past SST variability in the Aleutian archipelago. The transfer functions developed here can be applied to Mg/Ca records generated from long-lived specimens of C. nereostra turn to reconstruct northern North Pacific and Bering Sea SST variability for the past several hundred years.

Description: Hydrothermal fluid forms as seawater are modified through interactions with heat and the earth's crust. These fluids emanate back into ocean water at hydrothermal vents on the seafloor. A major goal of the study of hydrothermal chemistry is to better constrain the impact that hydrothermal emissions have on the chemistry of the broader ocean, and how this chemistry differs between the varied vents found around the world's oceans. Here, processes and factors affecting the chemistry of hydrothermal fluid at high-temperature black smoker vents and the surrounding lower temperature diffuse flow zones are discussed. Chemical reactions that occur at vents are also considered, including organic synthesis and the formation of metal sulfides. The relationship between metals, sulfide, depth, spreading rate, and type of host system is explored through existing data. Because of the ongoing nature of this review, figures will be updated as more hydrothermal data are collected. This will provide both a basic introduction to hydrothermal chemistry and a data-driven review of the chemistry of high-temperature hydrothermal vents.

Description: Highlights: • We report the results of a Scottish large group workshop on energy technologies. • There is strong public support for renewable energy and mixed opinions towards CCS. • The workshop was successful in initiating discussion around climate change and energy technologies. • Issues of trust, uncertainty, costs, benefits, values and emotions all inform public perceptions. • Need to take seriously the full range of factors that inform perceptions. Abstract: This paper presents the results of a large group process conducted in Edinburgh, Scotland investigating public perceptions of climate change and low-carbon energy technologies, specifically carbon dioxide capture and storage (CCS). The quantitative and qualitative results reported show that the participants were broadly supportive of efforts to reduce carbon dioxide emissions, and that there is an expressed preference for renewable energy technologies to be employed to achieve this. CCS was considered in detail during the research due to its climate mitigation potential; results show that the workshop participants were cautious about its deployment. The paper discusses a number of interrelated factors which appear to influence perceptions of CCS; factors such as the perceived costs and benefits of the technology, and people's personal values and trust in others all impacted upon participants’ attitudes towards the technology. The paper thus argues for the need to provide the public with broad-based, balanced and trustworthy information when discussing CCS, and to take seriously the full range of factors that influence public perceptions of low-carbon technologies.

Description: A link between atmospheric variability in the Tropics independent of ENSO and the Southern Annular Mode (SAM) is found based on seasonal mean data for austral summer. Variations associated with El Niño Southern Oscillation (ENSO) are removed usinga linear method and a Tropics Index (TI) is defined as the zonal average of the ENSO-removed 500 hPa geopotential height between 10°S and 10°N. Since the detrended TI shows no link to SST variability in the Tropics, it appears to be related to internal atmospheric variability. We find that the TI can explain about 40% variance of the SAM interannual variability and about 75% of the SAM long term trend between 1957/58 and 2001/02, where here the SAM includes the ENSO signal. Positive/negative values of the TI are associated with the positive/negative SAM. A possible link between the TI and global warming is noted.

Description: Highlights: • Global mean sea level simulated in interannual CORE simulations. • Regional sea level patterns simulated in interannual CORE simulations. • Theoretical foundation for analysis of global mean sea level and regional patterns. Abstract: We provide an assessment of sea level simulated in a suite of global ocean-sea ice models using the interannual CORE atmospheric state to determine surface ocean boundary buoyancy and momentum fluxes. These CORE-II simulations are compared amongst themselves as well as to observation-based estimates. We focus on the final 15 years of the simulations (1993–2007), as this is a period where the CORE-II atmospheric state is well sampled, and it allows us to compare sea level related fields to both satellite and in situ analyses. The ensemble mean of the CORE-II simulations broadly agree with various global and regional observation-based analyses during this period, though with the global mean thermosteric sea level rise biased low relative to observation-based analyses. The simulations reveal a positive trend in dynamic sea level in the west Pacific and negative trend in the east, with this trend arising from wind shifts and regional changes in upper 700 m ocean heat content. The models also exhibit a thermosteric sea level rise in the subpolar North Atlantic associated with a transition around 1995/1996 of the North Atlantic Oscillation to its negative phase, and the advection of warm subtropical waters into the subpolar gyre. Sea level trends are predominantly associated with steric trends, with thermosteric effects generally far larger than halosteric effects, except in the Arctic and North Atlantic. There is a general anti-correlation between thermosteric and halosteric effects for much of the World Ocean, associated with density compensated changes.

Description: Highlights • Geochemical data from high-T granodiorites and granites imply lower crustal amphibolite melting. • New U-Pb zircon ages imply syn-orogenic intrusion • New Sr-Nd-Pb isotope data imply ancient crustal sources and constrain AFC processes Abstract: The Gawib pluton (Damara Belt, Namibia) consists of two main intrusive rock types; magnesian, calc-alkaline, mostly metaluminous hornblende- and titanite-bearing granodiorites and magnesian to ferroan, metaluminous to slightly peraluminous calc-alkaline granites. Uranium-Pb zircon data obtained on the granodiorites gave concordant ages of 548.5 ± 5.6 Ma indicating that the pluton belongs to the early syn-orogenic magmatism in the Damara orogen. Major and trace element variations indicate that fractional crystallization was the major rock-forming mechanism for the granodiorites. In the absence of high-precision geochronological data, the granites may represent more advanced fractionation products of the granodiorites although distinct Ba-Sr-Rb relationships preclude a direct derivation of the granites from the exposed granodiorites. If the granites originated by extensive fractional crystallization from similar granodiorites, they can only be derived from high-Ba, high-Sr, low-Rb granodiorites. Crustal contamination was also important in the petrogenesis of both rock types (granodiorites: ε Nd(init.): -7 to -13; 87Sr/86Sr(init.): 0.708-0.713; granites: ε Nd(init): -14 to -18; 87Sr/86Sr(init.): 0.712-0.726). In contrast to the granodiorites, the granites show more radiogenic 87Sr/86Sr ratios and less radiogenic ε Nd values indicating different contaminants for both rock types. ε Nd vs. MgO relationships imply some genetic link to isotopically unevolved quartz diorites similar to those observed at the Palmental complex. This pluton, however, is located c. 80 km NE from the Gawib pluton and probably cannot be viewed as the direct source of the Gawib granodiorites. If such a relationship is allowed, the granodiorites must be viewed as hybrid rocks containing a juvenile component because they were derived from unevolved quartz diorites by fractional crystallization. In addition, AFC processe have also played a role implying that the granodiorites contain also a reprocessed crustal component. Alternatively, comparison with experimentally derived melts imply that the granodiorites are generated by dehydration melting of a mafic, amphibole-bearing lower crustal source. Chemical parameters of the granodiorites compared to experimental results indicate high temperatures of c. 1040 °C. Zirconium saturation temperatures obtained on the most primitive samples gave c. 830 °C whereas apatite saturation temperatures obtained on the same samples give temperatures of c. 960-980 °C; the latter seems to be a more reliable temperature estimate. Interpretation of geochemical and isotope data from the complex suggest that the early synorogenic Pan-African igneous activity in this part of the Damara Belt was a high-temperature intra-crustal event. In contrast to igneous processes along active continental margins that produce also intermediate plutons with calc-alkaline affinities, this igneous event was not a major crust-forming episode and the granodiorites represent mostly reprocessed crustal material.

Description: Mate choice for compatible genes is often based on genes of the major histocompatibility complex (MHC). Although MHC-based mate choice is commonly observed in female choice, male mate choice remains elusive. In particular, if males have intense paternal care and are thus the choosing sex, male choice for females with dissimilar MHC can be expected. Here, we investigated whether male mate choice relies on MHC class I genes in the sex-role reversed pipefish Syngnathus typhle. In a mate choice experiment, we determined the relative importance of visual and olfactory cues by manipulating visibility and olfaction. We found that pipefish males chose females that maximize sequence-based amino acid distance between MHC class I genotypes in the offspring when olfactory cues were present. Under visual cues, large females were chosen, but in the absence of visual cues, the choice pattern was reversed. The use of sex-role reversed species thus revealed that sexual selection can lead to the evolution of male mate choice for MHC class I genes.