ALBERT

Description: Fish stocks have made surprising comebacks in the North and Baltic seas. But much remains to be done. Beginning in January, new EU laws will impose more sustainable practices with stricter quotas and by-catch rules.

Description: Marine organic-carbon-rich deposits occur where there is an ample rain of organic particulate material to the sea floor and conditions favorable to its preservation. It was originally thought that the accumulation of organic carbon (Corg) was dependent mostly on anoxic conditions at the site of deposition; two such environments, the stagnant basin and the O2 minimum, were often cited as models. High productivity in the overlying waters has become recognized to be of greater importance. In an overall evaluation of burial of Corg in marine sediments, it is apparent that terrigenous input of organic matter is the largest source, followed by marine organic matter fixed in highly productive coastal areas receiving nutrients from land. In terms of rich accumulations of marine organic matter most likely to generate petroleum, areas of ocean upwelling along continental margins are most significant.

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: On the Earth, the atmosphere, ocean, and land interact with each other. For example, an atmospheric pressure system directly influences the Sea Surface Heights (SSHs) in a barometric sense; the associated wind transfers momentum from the atmosphere into the ocean, which alters the ocean currents affecting again the SSHs. The integrated effects of all motion components directly influence the angular momentum of the Earth, while the integrated effect of all mass variations alters the Earth’s inertia. Both can excite the Earth Orientation Parameters (EOPs). In this study, we use the Community Earth System Model (CESM) to simulate mass and motion variations within a coupled climate system. The modeled mass and motion variations of all subcomponents are used to compute the total excitation functions, which then are compared to very precise global EOP observations, provided by the International Earth Rotation and Reference Systems Service (IERS). For further reference, the modeled excitation functions of the subcomponents are compared to operational excitations, provided by the German Research Centre for Geosciences (GFZ). This allows an evaluation of the global model behavior and of the subcomponents. Further, regions of particularly high influence on the excitations as well as regions of especially strong dynamical coupling are identified. Four CESM experiments were performed, one reference experiment featuring solely natural variations, while the others separate the influence of (I) a coupled ocean component; (II) the quasi-biennial oscillation (QBO) and (III) anthropogenic forcings, e.g. greenhouse gas (GHG) emissions and ozone depleting substances (ODS). The modeled EOPs are in good agreement with the reference data sets, but reveal an slight overestimation of the modeled atmospheric mass component in the North Pacific for annual to interannual timescales, leading to deviations in the X1 component. Analyzing variations among the CESM experiments reveal (I) the complete absence of interannual subtropical tropospheric jet variability when using a climatological ocean; (II) a significantly increased atmospheric mass variation in the arctic region in the absence of a QBO; and (III) hardly any modeled effect of the global dynamics with respect to anthropogenic forcings. Finally, the North Pacific - a region with particularly strong atmosphere-ocean coupling - is investigated, highlighting wind driven ocean mass variations within the model and GRACE observations. The identified significant wind patterns explain the modeled ocean mass variations and can be directly projected onto ERA-Interim data in order to estimate the independent GRACE observations. The here presented relation between the ERA-Interim winds and the GRACE gravity field observations supporting the following two conclusions: (I) ERA-Interim winds can be used to further refine GRACE observations; (II) GRACE observations contain assimilation worthy information for atmospheric models.

Description: Tropical South America is one of the three main centres of the global, zonal overturning circulation of the equatorial atmosphere (generally termed the 'Walker' circulation1). Although this area plays a key role in global climate cycles, little is known about South American climate history. Here we describe sediment cores and down-hole logging results of deep drilling in the Salar de Uyuni, on the Bolivian Altiplano, located in the tropical Andes. We demonstrate that during the past 50,000 years the Altiplano underwent important changes in effective moisture at both orbital (20,000-year) and millennial timescales. Long-duration wet periods, such as the Last Glacial Maximum—marked in the drill core by continuous deposition of lacustrine sediments—appear to have occurred in phase with summer insolation maxima produced by the Earth's precessional cycle. Short-duration, millennial events correlate well with North Atlantic cold events, including Heinrich events 1 and 2, as well as the Younger Dryas episode. At both millennial and orbital timescales, cold sea surface temperatures in the high-latitude North Atlantic were coeval with wet conditions in tropical South America, suggesting a common forcing.

Description: Long sediment cores recovered from the deep portions of Lake Titicaca are used to reconstruct the precipitation history of tropical South America for the past 25,000 years. Lake Titicaca was a deep, fresh, and continuously overflowing lake during the last glacial stage, from before 25,000 to 15,000 calibrated years before the present (cal yr B.P.), signifying that during the last glacial maximum (LGM), the Altiplano of Bolivia and Peru and much of the Amazon basin were wetter than today. The LGM in this part of the Andes is dated at 21,000 cal yr B.P., approximately coincident with the global LGM. Maximum aridity and lowest lake level occurred in the early and middle Holocene (8000 to 5500 cal yr B.P.) during a time of low summer insolation. Today, rising levels of Lake Titicaca and wet conditions in Amazonia are correlated with anomalously cold sea-surface temperatures in the northern equatorial Atlantic. Likewise, during the deglacial and Holocene periods, there were several millennial-scale wet phases on the Altiplano and in Amazonia that coincided with anomalously cold periods in the equatorial and high-latitude North Atlantic, such as the Younger Dryas.

Description: This article reviews the major findings of an intensive geological and geophysical study of the Brazilian margin and adjacent oceanic and continental areas. Most of the data fits well with standard plate models for Atlantic-type margins, with clearly recognizeable pre-rift, rift, proto-oceanic and oceanic stages. However there are significant problems regarding the nature of the crust beneath the margin and the position of the boundary between oceanic and continental crust.

Description: The stratigraphic successions exposed in Wadi El Mizeira have been dated through the analysis of the calcareous nannofossil assemblages. The results of this study indicate that the successions comprise the Santonian-Late Maastrichtian (Sudr Formation), the Paleocene (Esna Formation) and the Early Eocene (Thebes Formation). The following biozones were recognized: Late Santonian, CC16 Zone; Late Santonian/Early Campanian, CC17 Zone; Early Campanian, Aspidolithus parcus Zone (CC18) Zone; Late Maastrichtian, CC25c Zone; Early Paleocene (Late Danian), NP3 Zone and NP4 Zone; Late Paleocene (Thanethian-Selandian), NP5 Zone; Early Eocene, NP9b Zone, NP10a Zone, NP11 Zone, NP12 Zone and NP14 Zone. Several stratigraphic hiatus were recorded in the studied interval including the absence of Cretaceous nannofossil Zones CC19 to CC25b and CC26 as well as the early Paleocene Zones NP1 and NP2 and probably the basal part of Zone NP3, in addition to the absence of the Zones NP6 and NP7/8. These hiatus may be attributed to environmental conditions, structural activity and/or post depositional processes. This work represents the first attempt to evaluate the nannofossil taxa of the Wadi El Mizeira, Northeastern Sinai.

Description: Hemigrapsus sanguineus (Asian Shore Crab) has shown a remarkable ability to colonize rocky intertidal communities along the east coast of the United States since its introduction in the late 1980s and is an important predator of juvenile Mytilus edulis (Blue Mussel) in invaded habitats. In this study, we used two field-caging experiments and the Kaplan-Meier model to assess the impact of predation by Asian Shore Crab on the survival of juvenile Blue Mussels in an intertidal habitat of western Long Island Sound along the Connecticut coastline. Five treatment levels (high-density enclosure, low-density enclosure, exclosure, partial cage, and open plot) were used in the 2007 experiment. The high-density enclosure treatment was omitted in the 2010 experiment since there was no statistically significant difference in the proportion of mussels surviving between low- and high-density crab treatments in 2007. In 2007, we measured a statistically significant difference in mussel mortality between exclosure and crab-enclosure cages, with crabs lowering the median survival time for mussels from 15.4 to 7.6 days. In 2010, we again measured a statistically significant difference in mussel mortality between exclosure and crab-enclosure cages, suggesting a crab effect on mussel survival. In the 2010 experiment, approximately 25% of the mussel mortality was attributable to crab predation, which reduced median survival time for mussels from 12.8 to 5.6 days. The median survival time for mussels exposed to the full complement of factors affecting survival (open plots and partial cages) was only 2–3 days. Our study shows that predation by Asian crabs may account for up to 25% of the Blue Mussel mortality in the intertidal zone at Black Rock Harbor. Further studies focusing on the importance of other biotic and abiotic factors are needed to understand the apparent declines in Blue Mussel populations and the interannual variability in recruitment success in this area.

Description: In Moreton Bay, Queensland, the catch obtained using monofilament polyamide (PA) otter trawl-nets with multifilament polyethylene (PE) cod ends was compared with that obtained using multifilament PE trawl-nets of identical mesh opening (38 mm). Monofilament PA otter trawl-nets retained fewer small prawns ( 〈 24 mm carapace length) than conventional multifilament PE nets, but both nets caught similar quantities of larger prawns ( 〉 24 mm carapace length). The higher retention rate of small prawns by multifilament PE gear was reflected in the greater catch weights of Peraeus plebejus, Metapenaeus bennettae and Metapenaeopsis novaeguineae in those nets. Catch weights of larger prawn species such as Penaeus esculentus and Metapenaeus endeavouri did not differ between nets. Winter whiting (Sillago maculata) and squid (Loligo spp.) were trawled in similar abundance in both nets, although the monofilament retained fewer squid 〈 50 mm mantle length. More marketable ( 〉 15 cm carapace width) sand crabs (Portunus pelagicus) were caught in the monofilament net. There was not significant difference in the trash (noncommercial component) weight caught in both nets. Over the range of towing speeds tested (1.7–2.3 kn), use of monofilament nets significantly reduced total gear drag.

Description: It is well documented that animals take risk of predation into account when making decisions about how to behave in particular situations, often trading-off risk against opportunities for mating or acquiring energy. Such an ability implies that animals have reliable information about the risk of predation at a given place and time. Chemosensory cues are an important source of such information. They reliably reveal the presence of predators (or their presence in the immediate past) and may also provide information on predator activity level and diet. In certain circumstances (e.g., in the dark, for animals in hiding) they may be the only cues available. Although a vast literature exists on the responses of prey to predator chemosensory cues (or odours), these studies are widely scattered, from marine biology to biological control, and not well known or appreciated by behavioural ecologists. In this paper, we provide an exhaustive review of this literature, primarily in tabular form. We highlight some of the more representative examples in the text, and discuss some ecological and evolutionary aspects of the use of chemosensory information for prey decision making. Curiously, only one example illustrates the ability of birds to detect predator odours and we have found no examples for terrestrial insects, suggesting a fruitful area for future study.

Description: Surface sediments of thermokarst lakes along the temperature gradient were sampled in northwestern Siberia. The lakes were distributed through three environmental zones: typical tundra, southern tundra and forest-tundra, which were all situated within the continuous permafrost zone. Our investigation showed that the cladoceran communities in the lakes of the region are represented by diverse, abundant communities as reflected by the taxonomic richness and high diversity indices. The differences in the cladoceran assemblages were related to the limnological and geographical position, vegetation type, climate and water chemistry. The constrained redundancy analysis (RDA) indicated that the TJuly, water depth and both sulphate (SOf ~) and silicium (Si4*) concentrations statistically significant (p 〈 0.05) explained the variance in the cladoceran assemblage.

Description: Tephra provides regional chronostratigraphical marker horizons that can link different climate archives with highly needed accuracy and precision. The results presented in this work exemplify, however, that the intermittent storage of tephra in ice sheets and during its subsequent iceberg transport, especially during glacial stages, constitutes a potential source of serious error for the application of tephrochronology to Nordic Seas and North Atlantic sediment archives. The peak shard concentration of the rhyolitic component of the North Atlantic Ash Zone II (NAAZ-II) tephra complex, often used to correlate marine and ice core records in Marine Isotope Stage (MIS) 3, is shown to lag the eruption event by ca. 100–400 years in some North Atlantic and Norwegian Sea cores. While still allowing for a correlation of archives on millennial timescales, this time delay in deposition is a major obstacle when addressing the lead–lag relationship on short timescales (years to centuries). A precise and accurate determination of lead–lag relationships between archives recording different parts of the climate system is crucial in order to test hypotheses about the processes leading to abrupt climate change and to evaluate results from climate models. Copyright # 2011 John Wiley & Sons, Ltd.

Description: This study is based on a collection of Cephalopoda, belonging to the Zoological Museum, University of Copenhagen (Denmark), which Dr. J . Knudsen kindly entrusted to me. Most of the specimens were collected on the West African coast by different expeditions: "Dr. Th. Mortensen's Java-South Africa Expedition 1929-1930", the "Atlantide Expedition 1945-1946", "Dr. G. Thorson's Expedition to the Canary Islands 1947", and the "Galathea Expedition 1950-1952". Some other specimens from the West African coast or from other localities were added.

Description: Marine phytoplankton blooms are annual spring events that sustain active and diverse bloom-associated bacterial populations. Blooms vary considerably in terms of eukaryotic species composition and environmental conditions, but a limited number of heterotrophic bacterial lineages — primarily members of the Flavobacteriia, Alphaproteobacteria and Gammaproteobacteria — dominate these communities. In this Review, we discuss the central role that these bacteria have in transforming phytoplankton-derived organic matter and thus in biogeochemical nutrient cycling. On the basis of selected field and laboratory-based studies of flavobacteria and roseobacters, distinct metabolic strategies are emerging for these archetypal phytoplankton-associated taxa, which provide insights into the underlying mechanisms that dictate their behaviours during blooms.

Description: Modern competition research started with G.E. Hutchinson’s, Homage to Santa Rosalia, and his now-famous question “why are there so many species?” (Hutchinson 1959,1961). This confronted observed species richness with the competitive exclusion principle, a principle that had been derived from theory and from highly artificial experiments. It would always have been easy to point at the “artificial” character of the competitive exclusion principle. Indeed many researchers have refused to deal with Hutchinson’s question because they considered it a pseudo-problem, which arose from a contradiction between overly simplified theory and complicated reality. However, those who took Hutchinson’s challenge seriously have gained fundamental insights into how competition plays out in nature, how species coexist, and how communities function. In this final chapter we attempt to synthesize these insights as they have been presented in this book. We focus on six key topics: - Identification of major trade-off axes (Sect. 8.1) - Confirmation of the “intermediate disturbance hypothesis”, and detection of interactions among competition, resource supply, predation and disturbance in field experiments (Sect. 8.2) - The interplay of space colonization, dispersal and neighborhood competition in sessile communities (Sect. 8.3) - Potential for chaotic, self-generated heterogeneity in communities (Sect. 8.4) - Role of exclusive resources in competition among mobile animals (Sect. 8.5) - Coexistence by slow exclusion (Sect. 8.6)

Description: An increasing body of research emphasizes that various biological processes in marine organisms are affected due to the uptake of anthropogenic atmospheric CO2 by the ocean in a process termed as ocean acidification (OA). The magnitude and direction of OA effects varies greatly among species and genotypes, highlighting different capabilities to adapt to increasing CO2. Direct OA impacts can be expected in the biochemical and elemental composition of primary producers (PP), which may be transferred to higher trophic levels, while indirect impacts can derive from altered trophic interactions as OA can modify plankton community composition. Fatty acids (FA) are the main component of lipids and cell membranes, with polyunsaturated fatty acids (PUFA) having additional important physiological and metabolic roles. Phytoplankton is the main source of essential biomolecules for heterotrophs as they cannot synthesize them de novo. Transference of organic essential macromolecules, in particular PUFA from phytoplankton-to-zooplankton-to-fish is a key factor influencing the life cycle of many organisms including humans. In the present work was investigated how OA influences the food quality of primary producers in terms of their fatty acid makeup at specie and community level, and how these OA-driven changes in the algae affect the fatty acid profile and life cycle of consumers. A combination of short- and long-term experiments on individual algal species, interaction between a single primary producer and one consumer, and natural plankton communities encompassing several producers and consumers were conducted in laboratory and natural conditions. In the short-term experiments at species level, the first and second laboratory study showed that CO2 can affect the biochemical composition of the diatoms Thalassiosira pseudonana and Cylindrotheca fusiformis, reducing their PUFA content; additionally the second diatom showed a reduced amount of amino acids. The interaction between a single primary producer and one consumer showed that when T. pseudonana cultured under high CO2 was used to feed the copepod Acartia tonsa, it affected their FA composition, severely impaired development and egg production rates. This demonstrated that a direct OA-driven shift in algal food quality can influence the reproduction success of upper trophic levels. At the community level, the third study conducted in a North Sea natural plankton assemblage subjected to a CO2 gradient showed that OA can modify phytoplankton community structures by favoring small phytoplankton cells with a comparatively low PUFA content. This community shift reduced PUFA content in primary producers was linked to a gradual PUFA decline in the dominant copepod species Calanus finmarchicus. In contrary, the fourth study revealed that the natural plankton community of the Baltic Sea experienced small differences in the algal community composition between CO2 treatments. The PUFA profile of the PP was influenced by phosphorus availability in the mesocosms, which was reflected by the PUFA composition of the copepod Acartia tonsa and Eurytemora affinis, but showed no significant CO2-related changes. This indicates that OA can affect the plankton community composition and its associated PUFA content, however this effect is lower in environments where communities are exposed to natural occurring high CO2 fluctuations like in the Baltic Sea, and that other essential nutrients have a stronger influence in the algal FA profile when present in limited amounts. In the long term experiments at species level, the fourth study determined that the coccolithophore Emiliania huxleyi and the diazotrophic cyanobacterium Trichodesmium sp. cultured over a thousand generations at high CO2 conditions showed a change in their FA content and composition. The FA profile of both algae presented a differentiate adaptation to high CO2 and particularly PUFA, which have metabolic functions in the cells, displayed evidence of adaptive evolution in both algae. These results highlight the diversity of OA responses among single plankton species and communities and that changes in biomolecular composition at the base of the marine food web are transferred to primary consumers. The thesis also highlights that the magnitude and direction of CO2-effects likely depends on the CO2 conditions and fluctuations the organisms are adapted to.

Description: The nature of subsidence near the ridge crest of the intermediate and fast spreading mid-ocean ridges of the Indian and Pacific Oceans is investigated using surface-ship bathymetry and magnetics profiles. The ridge can be divided into discrete sections, apparently bounded by distinct structural features such as major fracture zones, in which bathymetry plotted against crustal age forms a well-defined envelope with a width roughly the amplitude of the local bathymetry. The averaged bathymetry in all of the regions studied follows closely a square root of age subsidence curve which in most regions has a subsidence coefficient, C1, in the range of 340–390 m Myr−1/2. The best fitting subsidence curve, however, never reproduces the amplitude of the axial topographic high. The most notable region displaying unusual behaviour is the East Pacific Rise between 9°S and 22°S. In this region, the western flank of the ridge is subsiding at 200–225 m Myr−1/2 while the eastern flank is subsiding at ‘normal’ rates of 350–400 m Myr−1/2. Other anomalous areas include the region between the Easter Island hot spot and the Chile Rise triple junction in which the ridge crest is shallow and which is subsiding at rates of about 290 m Myr−1/2, and the region east of the Australia-Antarctic Discordance in which the northern flank is subsiding at 440 m Myr−1/2. This area may also be subsiding asymmetrically although there is not much data from the southern flank. The asymmetric subsidence in the 9°S-22°S region of the East Pacific Rise begins immediately at the ridge crest and the low subsidence rates on the west flank continue to at least 12 Myr old crust. Oligocene-aged crust on the western flank is subsiding at more normal rates, but is 500 m shallow with respect both to the world-wide average and to the conjugate crust on the eastern flank. The simplest model to explain these observations is that the western flank is underlain by a hotter mantle, perhaps as the result of upwelling resulting from the large-scale return circulation from the trenches. Depending on the depth of compensation, the observed asymmetry could result from a lateral temperature gradient of 0.05–0.10°C km−1 and a total lateral temperature variation of under 100°C.

Description: Males of Eledone cirrhosa grow to a size little over 600 g and normally have well-developed, and presumably active, reproductive organs from about 200 g upwards. Total weight of the genital bag is well correlated with total body weight (r= 0·906). Growth of the testis precedes that of the spermatophoric sac, and the size of neither of these reproductive components is predictable from body weight. The sizes of these organs and the estimated number and length of stored spermatophores are given for 100 g intervals of total body weight. No evidence was obtained for a seasonal trend in male maturity.

Description: A survey of the ecology of the octopus Eledone cirrhosa in Scottish waters is compiled from structured interviews with fishermen, records of occurrence in traps (for lobster and crab), and a research vessel survey. This species is widespread and common throughout the inshore waters covered by fishing activity (shoreline- 140 m) on bottom types ranging through rock, stones, sand and mud. It is caught in all months of the year but is especially common inshore in the summer (July-September) and further offshore on trawling grounds in October-December. The octopus is a normal and regular predator of large Crustacea (Hotnarus, Nephrops, Cancer) caught in commercial traps but gut contents yield little identifiable dietary remains.

Description: Owing to the turbulent nature of the ocean, mesoscale eddies are omnipresent. The impact of these transitory and approximately circular sea surface temperature fronts on the overlying atmosphere is not well known. Stationary fronts such as the Gulf Stream have been reported to lead to pronounced atmospheric changes1, 2. However, the impact of transient ocean eddies on the atmosphere has not been determined systematically, except on winds and to some extent clouds3, 4, 5, 6. Here, we examine the atmospheric conditions associated with over 600,000 individual eddies in the Southern Ocean, using satellite data. We show that ocean eddies locally affect near-surface wind, cloud properties and rainfall. The observed pattern of atmospheric change is consistent with a mechanism in which sea surface temperature anomalies associated with the oceanic eddies modify turbulence in the atmospheric boundary layer. In the case of cyclonic eddies, this modification triggers a slackening of near-surface winds, a decline in cloud fraction and water content, and a reduction in rainfall. We conclude that transient mesoscale ocean structures can significantly affect much larger atmospheric low-pressure systems that swiftly pass by at the latitudes investigated.

Description: Markedly different cooling histories for the hanging- and footwall of theVari detachment on Syros and Tinos islands, Greece, are revealed by zircon and apatite fission-track data. The Vari/Akrotiri unit in the hangingwall cooled slowly at rates of 5–15 ◦CMyr−1 since Late Cretaceous times. Samples from the Cycladic blueschist unit in the footwall of the detachment on Tinos Island have a mean zircon fission-track age of 10.0±1.0 Ma, which together with a published mean apatite fission-track age of 9.4±0.5 Ma indicates rapid cooling at rates of at least ∼60 ◦CMyr−1. We derive a minimum slip rate of ∼6.5 kmMyr−1 and a displacement of 〉∼20 km and propose that the development of the detachment in the thermally softened magmatic arc aided fast displacement. Intra-arc extension accomplished the final ∼6–9 km of exhumation of the Cycladic blueschists from ∼60 km depth. The fast-slipping intra-arc detachments did not cause much exhumation, but were important for regionalscale extension and the formation of the Aegean Sea.

Description: The ocean accounts for over 90% of the active pools of carbon on the Earth’s surface, with over 95% of marine carbon in the form of dissolved inorganic carbon (DIC) (Hedges and Keil 1995). Organic carbon dissolved in the ocean, suspended as particles or cells, and accumulating in sediments together constitute the other significant fractions of marine carbon, with organic carbon in the water column similar in quantity to the current atmospheric inventory of carbon dioxide. Isotopic partitioning among various inorganic and organic carbon phases reflects biological, physical and chemical processes, and the resulting fractionations are important tools in the study of modern and ancient carbon cycling. The focus of this review is on the isotopic geochemistry of marine organic carbon. It will begin by setting the stage with the isotopic patterns of DIC in the modern oceans. As will be discussed below, the distribution of inorganic carbon and related nutrient concentrations as well as DIC isotopic compositions are important influences on the quantity and isotopic character of organic carbon produced in marine surface waters. The remainder of the review will discuss isotope fractionation associated with the production and preservation of marine organic carbon. The combination of organic matter composition and 13C content is a potentially powerful approach for addressing the nature and pace of ecological and environmental change both in the modern and ancient ocean. This work reviews biogeochemical processes that generate, transform and ultimately preserve such signatures in marine sediments.

Description: We use data from recently installed broad-band seismographs on the islands of Crete, Gavdos, Santorini, Naxos and Samos in the Hellenic subduction zone to construct receiver function images of the crust and upper mantle from south of Crete into the Aegean Sea. The stations are equipped with STS-2 seismometers and they are operated by GFZ Potsdam, University of Chania and ETH Zürich. Teleseismic earthquakes recorded by these stations at epicentral distances between 35° and 95° have been used to calculate receiver functions. The receiver function method is a routinely used tool to detect crustal and upper-mantle discontinuities beneath a seismic station by isolating the P–S converted waves from the coda of the P wave. Converted P–S energy from the oceanic Moho of the subducted African Plate is clearly observed beneath Gavdos and Crete at a depth ranging from 44 to 69 km. This boundary continues to the north to nearly 100 km depth beneath Santorini island. Because of a lack of data the correlation of this phase is uncertain north of Santorini beneath the Aegean Sea. Moho depths were calculated from primary converted waves and multiply reflected waves between the Moho and the Earth's surface. Beneath southern and eastern Crete the Moho lies between 31 and 34 km depth. Beneath western and northern Crete the Moho is located at 32 and 39 km depth, respectively, and behaves as a reversed crust–mantle velocity contrast, possibly caused by hydration and serpentinization of the forearc mantle peridotite. The Moho beneath Gavdos island located south of Crete in the Libyan Sea is at 26 km depth, indicating that the crust south of the Crete microcontinent is also thinning towards the Mediterranean ridge. This makes it unlikely that part of the crust in Crete consists of accreted sediments transported there during the present-day subduction process which began approximately 15 Ma because the backstop, i.e. the boundary between the current accretionary wedge of the Mediterranean ridge and the Crete microcontinent, is located approximately 100 km south of Gavdos. A seismic boundary at 32 km depth beneath Santorini island probably marks the crustal base of the Crete microcontinent. A shallower seismic interface beneath Santorini at 20–25 km depth may mark the depth of the detachment between the Crete microcontinent and the overlying Aegean subplate. The Moho in the central and northern Aegean, at Naxos and Samos, is observed at 25 and 28 km depth, respectively. Assuming a stretching factor of 1.2–1.3, crustal thickness in the Aegean was 30–35 km at the inception of the extensional regime in the Middle Miocene.

Description: Benthic foraminiferal assemblages from a core southwest of Disko Bugt provide a Holocene perspective (last ~7 ka BP) on ice-sheet/ocean interactions between the West Greenland Current (WGC) and the West Greenland ice sheet. Changes in the fauna reveal significant variations in the water mass properties (temperature and salinity) of the WGC through time. From 7.3 to 6.2 ka BP, a relatively warm/strong WGC influences ice-sheet melt in Disko Bugt and causes enhanced meltwater production, resulting in low surface-water productivity. The most favourable oceanographic conditions occur from 5.5 to 3.5 ka BP, associated with ‘thermal optimum-like’ conditions, encompassing minimum ice sheet extent in the Disko Bugt area. These conditions are attributed to: (1) reduced meltwater influence as the ice sheet is land based and (2) enhanced contribution of warm/saline water masses from the Irminger Current to the WGC. The transition into the late Holocene (last ~3.5 ka BP) is characterized by a cooling of oceanographic conditions, caused by increased advection of cold/low-salinity water masses from the East Greenland Current. A longer-term late-Holocene cooling trend within the WGC is attributed to the onset of Neoglacial cooling within the North Atlantic region. Superimposed on this cooling trend, multicentennial-scale variability within the WGC matches reconstructions from a nearby coring site in Disko Bugt as follows: (1) cooling at ~2.5 ka BP, linked to the 2.7 ka BP ‘cooling event’; (2) a warm phase centred at 1.8 ka BP, associated with the ‘Roman Warm Period’; (3) slight warming between 1.4 and 0.9 ka BP, linked to the ‘Medieval Climate Anomaly’; (4) severe cooling of the WGC after 0.9 ka BP, culminating at 0.3 ka BP during the ‘Little Ice Age’. We show that multicentennial-scale palaeoceanography variability along the West Greenland margin is driven by ocean forcing, i.e. variations in the relative contribution of Atlantic (Irminger Current) and Polar (East Greenland Current) water masses to the WGC during the last ~7 ka BP, influencing ice sheet dynamics.

Description: Secondary minerals found in fracture fillings and in fragments of altered basalt from Holes 417A and 417D were studied by both X-ray diffraction and chemical techniques. Minerals found in fracture fillings from Hole 417A are dominated by montmorillonite, "protoceládonite," analcite, and lesser saponite; celadonite and ferrosaponite are the characteristic secondary minerals in Hole 417D fracture fillings. Assuming that minerals found in such fracture fillings reflect the composition of the secondary fluids that produced them, it is apparent that those from Hole 417A were dominantly Al-rich, while those from Hole 417D were more enriched in Fe, Mg, and K. X-ray diffraction study of bulk samples support such fundamental differences in secondary mineralogy. In addition, the X-ray data on bulk samples suggest that primary plagioclase is the feldspar in Hole 417D rocks, and secondary potassium feldspar is the feldspar in Hole 417A altered rocks. Using available published data on secondary miner?1" found in other altered oceanic crust, it is possible to interpret the differences in secondary mineralogy that exist between the two sites. Secondary minerals present in Hole 417D rocks are believed to have formed under hydrothermally influenced, low temperature, nonoxidative diagenesis; whereas, those present in Hole 417A were produced under similarly low temperatures, but much more highly oxidizing conditions. The fundamental differences in secondary mineralogy between the two sites can be best explained by the accompanying remobilization of elements that involved plagioclase alteration in Hole 417A rocks. A comparison of the composition of Hole 417A and 417D secondary minerals with those found in younger crust suggests that the age of crust, influenced by the changing conditions of alteration, control the chemistry of secondary minerals found in available pore spaces in altered rocks. Minerals found in young crust (〈15 m.y.B.P.) are highly Mg-rich; minerals found in crust of intermediate age (—15-50 m.y.B.P.) are dominantly enriched in Fe and Mg; and those found in older crust have higher contents of Al and K.

Description: ln the past, analysis of habitat choice by marine nekton has been hampered by limited access to its environment. We suggest a method to facilitate study of habitat choice, using data gathered from videotapes. The aims of this study were (a) to identify members of a particular nekton assemblage, and (b) to identify environmental variables important to the assemblage as a whole. Data on species and environmental variables came from Videotapes of a sandy-bottom shelf area (60m depth) in the Gulf of Mexico off Pensacola, Florida, taken by a remote-controlled submersible travelling along defined transects. We analyzed these Videotapes to derive Information on habitat use of several species of fishes and large invertebrates. We divided the transects into sections which were homo· geneaus for bottom type and algal coverage, and in each section measured habitat variables and abundances of the most common and reliably identifiable species of demersal nekton. Factor analysis of species' means for environmental variables identified patterns of habitat use among these species. The analysis identified these patterns by generating axes that represented environmental gradients. The patterns of habitat use by these species related to their preferences for different amounts of three·dimensional structure, algae, and infaunal and epifaunal organisms. We compared species distributions and habitat distributions on these axes to find which environmental gradients were of most importance in habitat selection by these species. We found that more species selected habitats on the basis of particular amounts of structure, fewer selected on the basis of algal coverage and infaunal organisms. Only one species seemed to select habitats on the basis of types or abundances of epifaunal organisms. Thus, amount of three-dimensional structure seemed an important variable to the sandy·bottom assemblage overall, followed by amount of algal coverage and types of infaunal organisms.

Description: We compared the diets of 4 CO-occurring species of penguin at sub-Antarctic Marion Island in light of mechanlsn~s thought to result in dietary differentiation. Calculation of overlap indices and correspondence analyses indicated a clear separation in the diets of the 3 penguin genera but considerable similarity between the congeneric species pair The pelagic foraging king penguin Aptenodytes patagonicus consumed mainly myctophid fish, whereas the near-to offshore foraging macaroni penguin Eudyptes chrysolophus and rockhopper penguin E. chrysocome both consumed predominantly small pelagic crustaceans, although in different proportions. The inshore foraging gentoo penguin Pygoscelis papua fed largely on benthic nototheniid fish. Although king penguins rarely take small prey, differences in diet cannot be accounted for solely on the basis of prey size selection. Different diving capabilities may have some role in dietary differentiation, however, we consider prey availability in the apparently distinct feeding zones to explain most of the differences in the diets of the 4 species of penguins at Marion Island. The daily population food requirements of the respective penguin species at the Prince Edward Islands (comprising Marion and Prince Edward islands) increased with Increasing species foraging range. The mainly benthic nature of the prey in the inshore area, compared with the more easily replenished pelagic food stocks, probably explains the differences in food ava11abi.lity that sustain the greater food demands of the large populations of pelagic and offshore foragers.

Description: Sperm whales Physeter macrocephalus were observed off the Galapagos Islands between late February and April 1985, a year of cool sea-surface temperatures (SST), and January to June 1987, an 'El Nino' year of warm SST Distribu- tlon, abundance and diet of sperm whales were similar in both years. However, in 1987 they appeared to have a lower feeding success, as ind~cated by a reduced rate of observing faeces, and dived to shallower depths. Excretion rates were negatively correlated with sea-surface temperatures.

Description: Mud diapirism has recently been recognized in several modern accretionary wedges. It provides an important means of dewatering accretionary wedges and should be regarded as an important process for producing the melanges found in both modern and ancient accretionary terranes. Mud diapirism affects a large area of the Barbados Ridge Accretionary Complex. The distribution of the mud diapirs appears to be primarily controlled by the presence of underconsolidated terrigenous submarine fan deposits that are being accreted to the complex. The frequency of diapir occurrence decreases northward as the fan becomes thinner. Mud diapirs are absent from the very eastern most part of the complex formed from sediments accreted at its toe, with the exception of a few mud volcanoes on the ocean floor in front of the complex. The initiation of diapirism appears to be spatially coincident with the onset of subcretion, or underplating, of sediment to the base of the complex at a ramp between two levels of decollement. It is proposed that the release of mud and pore water from the subcreted sediments is a direct or indirect cause of most of the mud diapirism in the accretionary complex. There is a range of diapiric form dependent on the viscosity of the mud, from mud volcanoes fed by low viscosity mud, to higher viscosity mud ridges. The diapirs in the eastern areas of the complex are generally mud volcanoes with narrow conduits feeding a surface mound. Mud ridges are prominent in the western parts of the complex. This is interpreted as reflecting a general westward decrease in the fluid content of the accretionary complex. Bottom-simulating seismic reflectors formed by gas hydrate are commonly developed in the areas of mud volcano occurrences. The presence of the hydrate indicates that large volumes of methane are being generated at depth in these regions. The generation of methane may be contributing to zones of overpressuring in the wedge. Methane may also be partly responsible for driving the diapiric material to the surface to form mud volcanoes. Ridges in the subducting oceanic crust beneath the accretionary complex locally enhance diapirism above their crests and southern flanks. Faults formed later in the development of the complex are more commonly associated with diapirism than those resulting from accretion at the toe of the wedge. These later faults play an important role in controlling the sites of individual mud volcanoes, chains of mud volcanoes, and mud ridges.

Description: Experimental fishing for flying squid (Ommastrephes bartrami) was continued in 1987 from both a Japanese vessel and a Canadian vessel in northeastern Pacific Ocean waters off the coast of British Columbia. Average squid catch rates (383 kg km-1) for the Japanese vessel was the highest obtained over the 3-yr experimental study period. Pomfret and blue shark remained the major by catch species, but as in 1986, marine mammal catch rate increased substantially over the previous year's level. A total of 90 marine mammals were caught by the two vessels combined, and while the average length of net required to catch one mammal was similar for the Canadian vessel over the past two years, catch rate increased (i.e., the average net length required to catch one mammal decreased) for the Japanese vessel in 1987.

Description: The cuttlefish ingests much skeleton from the crustaceans and fish it preys upon. The skeletal pieces are relatively large and their dimensions bear a close relationship to the length of the buccal mass and diameter of the oesophagus. The structures of the buccal mass are instrumental in the breakdown of prey and orientation of long pieces of skeleton to ensure their entry into the oesophagus. Many pieces of skeletal material present in the stomach contents still have attached muscles, showing that there is little, or no, external digestion. Skeletal material may be important for long-term maintenance of young Sepia in captivity.

Description: During Pliocene to Quaternary time, the central Aleutian forearc basin evolved in response to a combination of tectonic and climatic factors. Initially, along-trench transport of sediment and accretion of a frontal prism created the accommodation space to allow forearc basin deposition. Transport of sufficient sediment to overtop the bathymetrically high Amlia fracture zone and reach the central Aleutian arc began with glaciation of continental Alaska in the Pliocene. As the obliquely subducting Amlia fracture zone swept along the central Aleutian arc, it further affected the structural evolution of the forearc basins. The subduction of the Amlia fracture zone resulted in basin inversion and loss of accommodation space east of the migrating fracture zone. Conversely, west of Amlia fracture zone, accommodation space increased arcward of a large outer-arc high that formed, in part, by a thickening of arc basement. This difference in deformation is interpreted to be the result of a variation in interplate coupling across the Amlia fracture zone that was facilitated by increasing subduction obliquity, a change in orientation of the subducting Amlia fracture zone, and late Quaternary intensification of glaciation. The change in coupling is manifested by a possible tear in the subducting slab along the Amlia fracture zone. Differences in coupling across the Amlia fracture zone have important implications for the location of maximum slip during future great earthquakes. In addition, shaking during a great earthquake could trigger large mass failures of the summit platform, as evidenced by the presence of thick mass transport deposits of primarily Quaternary age that are found in the forearc basin west of the Amlia fracture zone.

Description: An influence of solar irradiance variations on Earth’s surface climate has been repeatedly suggested, based on correlations between solar variability and meteorological variables1. Specifically, weaker westerly winds have been observed in winters with a less active sun, for example at the minimum phase of the 11-year sunspot cycle2, 3, 4. With some possible exceptions5, 6, it has proved difficult for climate models to consistently reproduce this signal7, 8. Spectral Irradiance Monitor satellite measurements indicate that variations in solar ultraviolet irradiance may be larger than previously thought9. Here we drive an ocean–atmosphere climate model with ultraviolet irradiance variations based on these observations. We find that the model responds to the solar minimum with patterns in surface pressure and temperature that resemble the negative phase of the North Atlantic or Arctic Oscillation, of similar magnitude to observations. In our model, the anomalies descend through the depth of the extratropical winter atmosphere. If the updated measurements of solar ultraviolet irradiance are correct, low solar activity, as observed during recent years, drives cold winters in northern Europe and the United States, and mild winters over southern Europe and Canada, with little direct change in globally averaged temperature. Given the quasiregularity of the 11-year solar cycle, our findings may help improve decadal climate predictions for highly populated extratropical regions

Description: Thirteen types of octopodid paralarvae are recognized from Hawaiian waters, although the adults of only seven species (three are undescribed) are currently known from this area. The most common 11 paralarval types are described; five types can be identified with known adults. Stage II paralarvae differ from Stage I paralarvae by the presence of sucker buds on their arms. The number of suckers in Stage I paralarvae is characteristic for a species, as are their chromatophore patterns. Hatchlings have a high density of integumental pores containing secretory granules that may produce a mucous “drogue” to assist in offshore transport.

Description: Food samples from 27 Buller’s mollymawks Diomedea bulleri from the New Zealand region showed that cephalopods were, by frequency of occurrence and by mass, their preferred food. Fish, crustaceans, and tunicates, in decreasing order of importance, also were taken. Seventeen species of Cephalopoda were identified by their beaks, with 78.5% of individuals belonging to the Ommastrephidae (77% Nototodarus spp.) and 10% to the Histioteuthidae. The diet was compared with that of four other small species of Diomedea, and found to be similar to that of D. chrysostoma, D. irrorata, and D. cauta, but different from that of D. melanophris, whose preferred food is euphausiids. Squid-fishing operations around New Zealand may come into competition with Buller’s mollymawk.

Description: The Sanjiang Basin has received more attention in Mesozoic stratum and petroleum potential research because of its particularity in geographic and tectonic position. There remains debate on the basement structure of the basin since igneous rocks and faults make the structure and stratigraphy more complicated. In this paper we utilize gravity and magnetic data as well as petrophysical properties and drilling logs to understand the structure of the Sanjiang Basin. The study is focused on the comparison between the western and eastern parts of the basin. The comparison reveals that there are distinct differences in the gravity and magnetic field between the western and eastern parts. The integrated analysis of the gravity, magnetic, geological, petrophysical data and drilling logs indicates that the difference in the gravity and magnetic field results from the different basement structure and caprock formation of the two parts of the basin. The basement consists of three parts from west to east, the Proterozoic crystalline basement, the Neopaleozoic fold basement and the Lower Mesozoic fold basement separately. The Tongjiang–Yingchun Fault and the Qinglongshan–Xiaoheyan Fault controlled the formation and development of depressions and uplifts and also affected the sedimentation and volcanic activities of the basin. The Sanjiang Basin has relatively thin and stable crust thickness, varying around 33 km, and the deep structure has control and constraint over the shallow conformations.

Description: The squid Nototodarus gouldi (McCoy, 1888) was caught by bottom trawl in Port Phillip Bay, Australia in February 1985. The squid accumulates in its digestive gland high levels of trace metals, with up to 100 μg Cd g-1 dry tissue, 1 200 μg g-1 copper and 1 500 μg g-1 zinc and up to 24 Bq g-1 of the naturally occurring radionuclide polonium-210. The molecular binding of these elements in six squid was investigated using column chromatography. Two poorly resolved copper peaks were associated with proteins of average molecular weights of 11 500 and 18 000. The two squid containing the highest levels of cadmium in their digestive glands (44 and 88 μg g-1) had cadmium associated with a peak of molecular weight intermediate between the copper-binding peaks, but this peak was absent from squid containing lower levels of cadmium. Zinc was associated with ligands of less than 1 500 molecular weight. The 210Po eluted with proteins of greater than 70 000 molecular weight, and there was no evidence of binding to low molecular weight proteins. Different mechanisms appear to be involved in the binding and control of the four elements.

Description: Santorini, Greece is a major explosive volcano. The Santorini volcanic complex is composed of two active volcanoes—Nea Kameni and Mt. Columbo. Holocene eruptions have generated a variety of processes and deposits and eruption mechanisms pose significant hazards of various types. It has been recognized that, for major European volcanoes, few studies have focused on the social aspects of volcanic activity and little work has been conducted on public perceptions of hazard, risk and vulnerability. Such assessments are an important element of establishing public education programmes and developing volcano disaster management plans. We investigate perceptions of volcanic hazards on Santorini. We find that most residents know that Nea Kameni is active, but only 60% know that Mt. Columbo is active. Forty percent of residents fear that negative impacts on tourism will have the greatest effect on their community. In the event of an eruption, 43% of residents would try to evacuate the island by plane/ferry. Residents aged N50 have retained a memory of the effects of the last eruption at the island, whereas younger residents have no such knowledge. We find that dignitaries and municipal officers (those responsible for planning and managing disaster response) are informed about the history, hazards and effects of the volcanoes. However, there is no bemergency planQ for the island and there is confusion between various departments (Civil Defense, Fire, Police, etc.) about the emergency decision-making process. The resident population of Santorini is at high risk from the hazards associated with a future eruption.

Description: The morphology and structure of the submarine flanks of the Canary Islands were mapped using the GLORIA long-range side-scan sonar system, bathymetric multibeam systems, and sediment echosounders. Twelve young (〈2 Ma) giant landslides have been identified on the submarine flanks of the Canary Islands up to now. Older landslide events are long buried under a thick sediment cover due to high sedimentation rates around the Canary Islands. Most slides were found on the flanks of the youngest and most active islands of La Palma, El Hierro, and Tenerife, but young giant landslides were also identified on the flanks of the older (15–20 Ma) but still active eastern islands. Large-scale mass wasting is an important process during all periods of major magmatic activity. The long-lived volcanic constructive history of the islands of the Canary Archipelago is balanced by a correspondingly long history of destruction, resulting in a higher landslide frequency for the Canary Islands compared to the Hawaiian Islands, where giant landslides only occur late in the period of active shield growth. The lower stability of the flanks of the Canaries is probably due to the much steeper slopes of the islands, a result of the abundance of highly evolved intrusive and extrusive rocks. Another reason for the enhanced slope instability is the abundance of pyroclastic deposits on Canary Islands resulting from frequent explosive eruptions due to the elevated volatile contents in the highly alkalic magmas. Dike-induced rifting is most likely the main trigger mechanism for destabilization of the flanks. Flank collapses are a major geological hazard for the Canary Islands due to the sector collapses themselves as well as triggering of tsunamis. In at least one case, a giant lateral blast occurred when an active magmatic or hydrothermal system became unroofed during flank collapse.

Description: The following report is a synthesis of the main results of the OECD Cooperative Programme on Eutrophication. It is the outcome of several years' concerted effort by 18 Member countries. The objectives were to establish, through international cooperation, a basis for eutrophication control of inland waters (lakes and reservoirs in particular), and to develop better guidelines for fixing nutrient load criteria compatible with water use objectives. The present report is both complementary and supplementary to the four Regional Project Reports (2) already published. In parallel with the OECD study programme, progress has been made in other areas, particularly in dynamic modelling. The results of the OECD study and approach have already been successfully applied in several instances in North America, Europe and elsewhere. It can be anticipated that 0- while knowledge of eutrophication and its control methods are advancing -- the OECD results presented here will continue to provide a basic reference in eutrophication control studies.