ALBERT

Description: The vast majority of active volcanism that is located at plate boundaries can be easily explained by plate tectonic processes. Intraplate volcanism, which incorporates some of the smallest and largest volcanic events on Earth, cannot be successfully explained by a single process or model. The most volumetrically significant intraplate volcanic events are associated with the arrival of the head of a thermo-chemical anomaly rising from the deep mantle and impacting the base of the lithosphere. This event generates massive and short-lived magmatic activity over a wide area (up to 2000 km across), forming a large igneous province. A long-lived hotspot track can form over the mantle plume tail and is best illustrated by the formation of age progressive volcanic chains, such as the famous Hawaiian-Emperor chain. Millions of smaller solitary volcanic edifices, non-age progressive volcanic chains and provinces, on the other hand, have other potential mechanisms of origin. Potential models comprise decompression melting due to lithospheric extension, destabilization of fusible lithologies in the lithospheric mantle, small scale sub-lithospheric convection, or lithospheric delamination.

Description: Gas hydrates dissociation could induce or trigger submarine landslides, especially in upper continental slopes where hydrates are vulnerable to natural and artificial perturbations. This work investigates destabilization mechanisms of an upper continental slope undergoing hydrate dissociation and identifies spatiotemporal failure modes influenced by characteristics of the overburden above the hydrate-bearing layer (i.e. the hydrate reservoir). A Thermo-Hydro-Chemical coupled numerical model of transient pore pressure induced by hydrate dissociation is coupled with the limit equilibrium slope analysis method to study the spatiotemporal evolution of the potential sliding plane and to calculate the corresponding factor of safety. The results suggest that overpressure generated by the liberated fluid from hydrate dissociation is the primary reason for instability in a gentle marine slope. The study identifies three sliding modes, namely co-melting non-interface sliding, co-melting interface sliding, and post-melting non-interface sliding, depending on the overburden's characteristics, including overburden thickness, permeability, and cohesion. Co-melting non-interface sliding takes place during hydrate dissociation if the hydrate reservoir underlies a thin, pervious and low-cohesion overburden cover. For less permeable and more cohesive overburdens, the potential sliding plane is deeper and co-melting interface sliding could be triggered due to overpressure developed at the reservoir-overburden interface. If the hydrate reservoir is covered by a thick, low-permeability and slightly cohesive overburden, post-melting non-interface sliding could occur after the hydrates are completely dissociated. This failure is delayed, because the gas/water trapped at the interface during hydrate dissociation is insufficient to trigger instability due to very high overburden stresses. However, as the gas migrates upwards over time and encounters a weak zone in the overburden deposits, failure could happen within the overburden deposits even after hydrate dissociation stops. The findings help to improve our fundamental understanding about the destabilization mechanism and failure modes of the continental slopes undergoing hydrate dissociation, and to delineate the vulnerable configurations of the slopes.

Description: n our daily lives, we consume foods that have been transported, stored, prepared, cooked, or otherwise processed by ourselves or others. Food storage and preparation have drastic effects on the chemical composition of foods. Untargeted mass spectrometry analysis of food samples has the potential to increase our chemical understanding of these processes by detecting a broad spectrum of chemicals. We performed a time-based analysis of the chemical changes in foods during common preparations, such as fermentation, brewing, and ripening, using untargeted mass spectrometry and molecular networking. The data analysis workflow presented implements an approach to study changes in food chemistry that can reveal global alterations in chemical profiles, identify changes in abundance, as well as identify specific chemicals and their transformation products. The data generated in this study are publicly available, enabling the replication and re-analysis of these data in isolation, and serve as a baseline dataset for future investigations.

Description: A comparison of gouge and hammer coring techniques in intertidal wetland soils highlights a significant effect of soil compaction of up to 28% associated with the widely applied hammer coring method employed in Blue Carbon research. Hammer coring reduces the thickness of the soil profile and increases the dry bulk density, which results in an overestimation of the soil OC stock of up to 22%. In saltmarshes with multiple different soil units, we show that hammer coring is unsuitable for the calculation of OC stocks and should be avoided in favour of Russian or gouge cores. Compaction changes both soil dry bulk density and porosity and we show that resultant radiometric chronologies are compromised, almost doubling mass accumulation rates. While we show that the OC (%) content of these sediments is largely unchanged by coring method, the implication for OC burial rates are profound because of the significant effect of hammer coring on the calculation of soil mass accumlation rates.

Description: Seagrasses provide multiple ‘ecosystem services' in coastal waters, including carbon sequestration. However, this ‘Blue Carbon’ potential has been only evaluated for certain species from some areas of the world. In this study, we provide initial estimates on the magnitude and local variability of carbon sequestration, as organic carbon stocks, for seagrass meadows of Cymodocea nodosa (Ucria) Ascherson in the oceanic island of Gran Canaria (Canary Islands, Spain, central-eastern Atlantic). Six seagrass meadows were selected; at each meadow, cores inserted up to 30 cm in the seabed were collected in the ‘interior’, ‘edge’ and ‘unvegetated’ bottoms immediately adjacent to seagrass patches. We estimated organic carbon (Corg) pools by means of the Loss of Ignition (LOI) procedure. Overall, larger Corg pools were observed in the ‘interior’ and 'edges' of meadow patches than in adjacent ‘unvegetated’ bottoms. At the meadow-level, Corg pools were not predicted neither by the meadow area, nor by the mean shoot density, or sediment grain fractions. Overall, the total estimated stock was 86.20 ± 19.06 Mg C ha−1. By considering the total potential extension of seagrass meadows across the entire island perimeter, we estimated a total stock of 60.34 Gg of C, for a mean estimated financial value of 919,432.249 € (1313.47 € ha−1), which ranges between 351,631.35 € (502.33 € ha−1) and 1,498,954.45 € (2141.36 € ha−1), according to varying market prices in the last 5 years. This work highlights, therefore, the importance of meadows underpinned by C. nodosa not only at an ecological, but also at an economic level, in particular from the perspective of regional climate change adaptation strategies.

Description: Ciona intestinalis is within the group of taxa that are spreading globally and is one of the most thriving invasive marine species, known to depress both species richness and abundance at a local scale in distinct geographic areas. It is a dominant biofouling agent, associated with the decreasing economic incomes from aquaculture operations around the world. Ciona intestinalis was first observed in 2007 at Straumsvík in Southwest Iceland. The present study was designed to provide general information on its current distribution across Icelandic harbours. The species was found only on the SW coast of Iceland, in dense aggregations reaching up to 876 ind/m2 in all harbours from Grindavík to Akranes. The current work provides information that can be used to track the dispersal of C. intestinalis populations along the Icelandic coast and for the development of effective management decisions.

Description: Interest in microalgae-derived products is growing, mostly due to their unique characteristics and range of industrial applications. To obtain different products, one must employ specific pretreatments that retain the properties of the biologically active compounds extracted from microalgae biomass; thus, new extraction techniques require frequent upgrades. Due to increased interest in economically viable and ecologically friendly processes, new extraction methods that can be incorporated into microalgae biorefinery systems have become the main focus of research. Therefore, this review aims to address the potential applications, future prospects, and economic scenario of the new physicochemical treatments used in the extraction of bioactive microalgae compounds.

Description: Long-chain polyunsaturated fatty acids (LC-PUFAs) especially ω-3 fatty acids provide significant health benefits for human beings. However, ω-3 LC-PUFAs cannot be synthesized de novo in mammals. Traditionally, ω-3 LC-PUFAs are extracted from marine fish, and their production depends on sea fishing, which has not met ever-increasing global demand. To address the challenges, innovative cellular engineering strategies need to be developed. In nature, many fungi and microalgae are rich in ω-3 LC-PUFAs, representing promising sources of ω-3 LC-PUFAs. The latest progress in developing new cellular engineering strategies toward sustainable ω-3 LC-PUFAs production using fungi and microalga has demonstrated that they can to some extent address the supply shortage. In this review, we critically summarize the recent progress in enhancing the productivity in various ω-3 LC-PUFAs-producing organisms, as well as the latest efforts of biosynthesizing PUFAs in heterogenous biosystems. In addition, we also provide future perspectives in developing genetic toolkits for LC-PUFAs producing microbes so that cut-edging biotechnology such as gene stacking and genome editing can be further applied to increase the productivity of ω-3 LC-PUFAs.

Description: Factors affecting carotenoid extraction with edible oils were examined using edible brown seaweed, Sargassum horneri, as main sample. The results indicate that drying was essential to extract fucoxanthin (Fx) from S. horneri and physical (boiling) and chemical (acid/alkali) pretreatment of the wet sample increased the extraction rate of Fx. Additionally, more Fx was found from the dried S. horneri powder with a smaller particle size. The extraction rate of Fx is affected by the extraction temperature and time, showing that the effective extraction would be obtained at 50 °C within 12 hr extraction. Among the oils used, short-chain (C4 and C6) triacylglycerol (TAG) (SCT) and medium-chain (C8) TAG (MCT) could extract more Fx from S. horneri and more β-carotene and lutein from spinach and olive leaves. The relatively lower viscosity of SCT and MCT would be the most likely reason for the higher extraction rates of both TAGs.

Description: Sargassum fusiforme polysaccharides, acidic water-soluble polysaccharides extract from Sargassum fusiforme, are mainly composed of alginic acid, fucoidan and laminaran. Alginic acid is carboxyl-containing polysaccharide formed by joining β-D-mannuronic acid and α-L-guluronic acid through β-(1→4)/α-(1→4) glycosidic bond. Fucoidan, a natural water-soluble sulfated heteropolysaccharide with fucose and sulfuric acid groups as the core structure, is mainly linked by L-fucose through α-(1→3) glycosidic bond and has the strongest biological activity. Laminaran is mainly composed of β-D-glucose through β-(1→3) glycosidic bond linkage. Sargassum fusiforme polysaccharides have a variety of pharmacological activities, including antioxidant, anti-tumor, promoting immunity, anti-aging, prompting bone growth, lowering blood glucose, anti-coagulation, anti-virus, anti-bacteria, anti-fatigue, promoting growth and development, and skin protection. These activities are closely related to the functions of fucoidan in Sargassum fusiforme polysaccharides, which fucoidan is able to strengthen immune system and antioxidation in human body. In this review, the composition, the isolation and purification, and the biological activities of Sargassum fusiforme polysaccharides are discussed and can bereference for further study.

Description: Numerical simulation is important for practical and efficient assessment of hydrate reservoir formation stability and gas production potential. The history-matching simulation of hydrate gas production tests is complex due to coupled THM (thermo-hydro-mechanical) phenomena. The well log data from the Eastern Nankai Trough methane gas production site suggest vertically heterogeneous field properties. In the previous numerical simulation research of this site, the heterogeneous geological data were homogenized by adopting the standard mean-field theory, which can potentially lead to inaccurate simulation results due to the mesh size effect. By introducing new upscaling techniques for the permeability profiles and mechanical responses, a revised homogenization approach is proposed to improve the coupled THM simulation accuracy. In this study, seven gas production simulations of a hypothetical reservoir, six simulations of the Eastern Nankai Trough gas production test, and four simulations of the randomly generated site formation production test with different mesh sizes and different homogenization approaches were carried out to demonstrate that the proposed upscaling techniques can improve the accuracy of the simulation results with a coarse mesh model. This work, in turn, provides researchers and field engineers a much quicker way to assess the complex geomechanical behaviors of hydrate gas production site.

Description: Nitrous oxide is an important greenhouse gas and there is a need for sensitive techniques to study its distribution in the environment at concentrations near equilibrium with the atmosphere (9.6 nM in water at 20 °C). Here we present an electrochemical sensor that can quantify N2O in the nanomolar range. The sensor principle relies on a front guard cathode placed in front of the measuring cathode. This cathode is used to periodically block the flux of N2O towards the measuring cathode, thereby creating an amplitude in the signal. This signal amplitude is unaffected by drift in the baseline current and can be read at very high resolution, resulting in a sensitivity of 2 nM N2O for newly constructed sensors. Interference from oxygen is prevented by placing the front guard cathode in oxygen-consuming electrolyte. The sensor was field tested by measuring an N2O profile to a depth of 120 m in the oxygen minimum zone of the Eastern Tropical North Pacific Ocean (ETNP) off the coast of Mexico.

Description: The ability of consumers to convert ingested carbon into growth is critical for secondary production and trophic transfer. We conducted laboratory experiments to investigate the effect of different prey and concentration on the ingestion rate (IR), egg production rate (EPR) and egg production efficiency (EPE) of the ubiquitous copepod, Acartia tonsa. Experiments were run at several prey concentrations, ranging from 11 to 1132 μgC L–1, of the diatom Thalassiosira weissflogii, the autotrophic dinoflagellate Prorocentrum minimum, the heterotrophic dinoflagellate Oxyrrhis sp., the flagellate Dunaliella tertiolecta, and the bacterivorous scuticociliate Uronema sp. IR increased curvilinearly with concentration for all diets. EPR also increased curvilinearly with increasing food concentration similar to IR, with the exception of the flagellate diet, for which EPR decreased linearly with food concentration. EPR ranked as T. weissflogii 〉 P. minimum 〉 Oxyrrhis sp. = Uronema sp. 〉 D. tertiolecta. IR and EPR were linearly related, except for flagellate diet. The slope of the carbon-based relationship between IR and EPR, the egg production efficiency (EPE), was highest for the diatom (77.5%) and lowest for the scuticociliate (4.2%). Egg production was not correlated to ingestion of the flagellate offered to A. tonsa. We conclude that of the five prey species, the diatom T. weissflogii is the best prey to promote A. tonsa reproduction, to optimize trophic transfer efficiency, and to increase mass cultivation of this species.

Description: Geochemical patterns in the environment are always the result of certain processes. Therefore, it is essential to decipher a process to properly evaluate the environmental role and potential of chemical elements/compounds. This allows the distinction between natural and anthropogenic influence on elemental concentrations. However, if the compositional nature of geochemical data is neglected, erroneous or misleading conclusions regarding the processes involved are probable. In this study the reconstruction of depositional environments and processes through the Holocene in two sediment cores obtained from submerged sinkholes located on the island of Mljet, Croatia, was performed by taking into account the compositional nature of geochemical, mineralogical and grainsize data. Problems involving compositional data are always multivariate; for example, the concentration of a single element does not carry any interpretative information, as only the ratios between elements do. This has led to the discovery of a large number of geochemical proxies based on elemental ratios, which describe certain environmental conditions and processes involved. Nevertheless, some proxies have been found to be restricted to only some specific environments, thus preventing them from being used in general; therefore, some kind of relation between different proxies is necessary to obtain final conclusions. However, when using simple elemental ratios, those correlations cannot be obtained due to the nature of compositional data. With a sequential binary partition of a compositional vector, orthonormal log ratio (olr) coordinates (proxies) can be constructed. When based on expert knowledge, those proxies fully acknowledge the geochemical properties of the chosen elements with one major difference - that the correlation between newly obtained variables is mathematically well grounded. As a result, the final conclusion is more accurate. In this research, geochemical proxies obtained as a representation in olr coordinates of the elements that are enriched compared to the local soil were used to perform principal component analyses. It helped to unravel the evolution of sedimentary environments. Mineralogical (XRD and heavy mineral data) and grain size analyses supported the conclusions obtained based solely on geochemical data. Furthermore, data analysis suggests that the proxies for redox conditions described in the literature should be used with caution, as their use is somewhat limited.

Description: New antifungals are increasingly needed due to the emergence of resistant fungal strains. Traditional antifungal assays are laborious and require significant amounts of samples. The present work presents a new proposal to evaluate antifungal activity and antagonism among fungal species, based on experiments of fungal culture and co-culture, 1H NMR profile of fungal culture extracts and chemometrics. In order to develop the work, six axenic cultures of fungi that infested fruits (Fusarium guttiforme, Pestalotiopsis diospyri, Phoma caricae-papayae, Colletotrichum horii, Phytophthora palmivora, and C. gloeosporioides), and co-cultures of all possible combination among them were performed (totalizing 63 experiments). All fungal extracts were evaluated by 1H NMR followed by Principal Component Analyses (PCA) in order to determine spectral dissimilarity among the extracts. Results showed that 1H NMR data evaluated by PCA were capable to predict both antagonism and antifungal activity. Traditional antifungal in vitro assays of active and inactive extracts were also performed in order to prove the prediction made by PCA. The obtained data showed that the approach is an outstanding tool to simultaneously obtain and evaluate bioactive compounds because: it was able to predict the activity of five different extracts in a collection of sixty-three, which would be much more difficult and time consuming if applied randomly; most important antifungal extracts are indicated by PCA; hundreds of traditional in vitro assays are avoid; and, the method is very time and money saving.

Description: Highlights • Total modeled carbon cycling at disturbed sites is lower than at reference sites. • Projected microbial loop functioning is reduced 26 years after sediment disturbance. • Estimated faunal respiration has recovered from sediment disturbance. • Estimated microbial respiration has not recovered from the sediment disturbance. Abstract Due to the predicted future demand for critical metals, abyssal plains covered with polymetallic nodules are currently being prospected for deep-seabed mining. Deep-seabed mining will lead to significant sediment disturbance over large spatial scales and for extended periods of time. The environmental impact of a small-scale sediment disturbance was studied during the ‘DISturbance and reCOLonization’ (DISCOL) experiment in the Peru Basin in 1989 when 10.8 km2 of seafloor were ploughed with a plough harrow. Here, we present a detailed description of carbon-based food-web models constructed from various datasets collected in 2015, 26 years after the experiment. Detailed observations of the benthic food web were made at three distinct sites: inside 26-year old plough tracks (IPT, subjected to direct impact from ploughing), outside the plough tracks (OPT, exposed to settling of resuspended sediment), and at reference sites (REF, no impact). The observations were used to develop highly-resolved food-web models for each site that quantified the carbon (C) fluxes between biotic (ranging from prokaryotes to various functional groups in meio-, macro-, and megafauna) and abiotic (e.g. detritus) compartments. The model outputs were used to estimate total system throughput, i.e., the sum of all C flows in the food web (the ‘ecological size’ of the system), and microbial loop functioning, i.e., the C-cycling through the prokaryotic compartment for each site. Both the estimated total system throughput and the microbial loop cycling were significantly reduced (by 16% and 35%, respectively) inside the plough tracks compared to the other two sites. Site differences in modelled faunal respiration varied among the different faunal compartments. Overall, modelled faunal respiration appeared to have recovered to, or exceeded reference values after 26-years. The model results indicate that food-web functioning, and especially the microbial loop, have not recovered from the disturbance that was inflicted on the abyssal site 26 years ago.

Description: Highlights: • Crystal structure of the malaria parasite lipocalin • Comparative analysis of lipocalin superfamily members in alveolate genomes • Localization of PfLipocalin to the parasitophorous vacuole and food vacuole • Reverse genetics reveal PfLipocalin function in oxidative damage control Summary: Proteins of the lipocalin family are known to bind small hydrophobic ligands and are involved in various physiological processes ranging from lipid transport to oxidative stress responses. The genome of the malaria parasite Plasmodium falciparum contains a single protein PF3D7_0925900 with a lipocalin signature. Using crystallography and small-angle X-ray scattering, we show that the protein has a tetrameric structure of typical lipocalin monomers; hence we name it P. falciparum lipocalin (PfLCN). We show that PfLCN is expressed in the intraerythrocytic stages of the parasite and localizes to the parasitophorous and food vacuoles. Conditional knockdown of PfLCN impairs parasite development, which can be rescued by treatment with the radical scavenger Trolox or by temporal inhibition of hemoglobin digestion. This suggests a key function of PfLCN in counteracting oxidative stress-induced cell damage during multiplication of parasites within erythrocytes.

Description: Eco-friendly, cost efficient and effective extraction methods have become significant for the industries applying zero waste principles. The two main objectives of this study were; to examine fucoxanthin extraction from wet Phaeodactylum tricornutum using subcritical fluid extraction and to characterize the residual biomass in order to determine the potential application areas. The highest fucoxanthin yield of 0.69 ± 0.05 mg/g wet cell weight was achieved using methanol with solvent-to-solid ratio of 200:1 at 120 rpm, 20 MPa pressure and at 35 °C for 60 min by subcritical extraction. Microscopy images showed that most of the cells were disrupted and intracellular components were effectively released. Based on the results of energy dispersive spectroscopy, biomass contained a mixture of organic molecules including mainly carbon (57–72%), oxygen (26–41%), magnesium (0.6–1.4%) and silica (0.4–1%) (wt%). These results make the residual biomass a potential candidate for various areas such as bioenergy, material sciences and sensor technologies.

Description: In a short note of 1998 Davankov questioned the generally accepted notion that the unique features of the planet Earth, namely, the presence of life and atmospheric oxygen are inseparably bonded as a case and effect. Indeed, photosynthesis in terrestrial and aquatic phototrophs simultaneously produces oxygen and carbohydrates in almost equal amounts. Since the degradation of organic matter through burning or rotting also consumes an equivalent amount of oxygen, the total masses of oxygen and organic material must always remain comparable. This correlation for Earth appears to be drastically distorted in favor of oxygen, thus disproving the still widespread delusion of biogenic origin of atmospheric oxygen. Instead, by analyzing more recent data on the balance between oxygen and organics we arrive at the conclusion that radiolysis of water vapors with the preferential dissipation of hydrogen to space, most probably, was the major source of the free and oxidation-spent oxygen. The present review tries to illuminate the most important uncertainties that still remain to be clarified before an interdisciplinary and scientifically-balanced picture on the evolution of Earth gets settled.

Description: The concept of biosorption results from the “passive” (nonmetabolic) interaction of a chemical species with a particle of a biological material. This interaction can be practically exploited, for example, for removal of toxic substances of wastewaters or for the enrichment of a fertilizer with micronutrients. In this work, equilibrium and dynamic data obtained with “low-cost” biomaterials of algal waste or invasive seaweed species have been reviewed and critically analyzed in the context of a circular economy. The concept of a biosorption unit, oriented to the valorization of any solid residual material of algal biomass, can be considered as a real possibility in a biorefinery process; but to accomplish this goal it is necessary that the emphasis on research must definitely move from laboratory scale toward pilot plant assays.

Description: Carnivorous gelatinous zooplankton (GZ) can be very abundant in marine ecosystems around the globe and exert considerable predation pressures on micro- to macrozooplankton as well as larval and juvenile fish. As these species are in many cases intermediate and top predators, their biomass can be easily evaluated, which could indicate overall food web stability or alteration. There is growing concern worldwide about increasing abundances of GZ species and consequently negative impacts on food webs and human coastal zones activities. In this paper, I present a case study from a shallow Danish cove and a long-term record spanning 29 years (1991–2019) obtained by unconventional means. Jellyfish were collected using horizontal sub-surface net tows in August and September during a summer student class. Sea surface temperature and chlorophyll a concentration were measured in parallel. No clear long-term trend in jellyfish biomass could be seen, whereas the values were highly variable from year to year. This is in contrast with other published Scandinavian long-term GZ time series. Sea surface temperature and chlorophyll a concentration had significant (and interactive) effects on the jellyfish biomass in Kertinge Nor. The scarcity and shortness of GZ long-term series do not allow solid conclusions in most marine ecosystems, so it becomes clear that publishing time series (even with small spatial extent) can contribute to improve the perception of interannual GZ population developments. Thus, I strongly recommend extending monitoring activities, explicitly including GZ taxa, in as many marine ecosystems as feasible.

Description: This paper describes methods of obtaining improved estimates of long-term sea level trends for the British Isles. This is achieved by lengthening the sea level records where possible, then removing known sources of variability, and then further adjusting for datum errors that are revealed by the previous processes after verification using metadata from archived sources. Local sea level variability is accounted for using a tide and surge model. Far field variability is accounted for using a “common mode”. This combination reduces the residual variability seen at tide gauges around the coast of the British Isles to the point that a number of previously unrecognised steps in individual records become apparent, permitting a higher level of quality control to be applied. A comprehensive data archaeology exercise was carried out which showed that these step-like errors are mostly coincident with recorded site-specific changes in instrumentation, and that in many cases the periodic tide gauge calibration records can be used to quantify these steps. A smaller number of steps are confirmed by “buddy-checking” against neighbouring tide gauges. After accounting for the observed steps, using levelling information where possible and an empirical fit otherwise, the records become significantly more consistent. The steps are not found to make a large difference to the trend and acceleration observed in UK sea level overall, but their correction results in much more consistent estimates of first order (Sea Level Rise) and second order (Sea Level Acceleration) trends over this 60-year period. We find a mean rate of sea level rise of 2.39 ± 0.27 mm yr−1, and an acceleration of 0.058 ± 0.030 mm yr−2 between Jan. 1958 and Dec. 2018. The cleaner dataset also permits us to show more clearly that the variability other than that derived from local meteorology is indeed consistent around the UK, and relates to sea level changes along the eastern boundary of the North Atlantic.

Description: Fucoxanthin is the major abundant xanthophyll in macro- and micro-algae as a component of photosynthetic light-harvesting complexes for photosynthesis and photoprotection. Nowadays, widespread application of fucoxanthin in food industry, pharmaceutical, and medical purposes are increasing. The current issue attracts the attention of researchers for producing of carotenoid from its natural resources, especially algae. Againts macroalgae, microalgae have rapid growth with the same source of food. In addition, they can grow from variety of situations and environmental conditions to produce a specific biochemical product. Microalgae, e.g. Tisochrysis lutea (T. lutea), can be cultivated under controlled conditions, low cost, and higher concentration of fucoxanthin. This review presents some of nutraceutical effects of fucoxanthin for human health and then, in particular, recent biotechnological developments in bioprocessing of this valuable product including, cultivation, harvesting, extraction, and purification, from T. lutea.

Description: Pretreatment of microalgal biomass possessing rigid cell wall is a critical step for enhancing the efficiency of microalgal biorefinery. However, the conventional pretreatment processes suffer the drawbacks of complex processing steps, long processing time, low conversion efficiency and high processing costs. This significantly hinders the industrial applicability of microalgal biorefinery. The innovative electricity-aid pretreatment techniques serve as a promising processing tool to extensively enhance the release of intracellular substances from microalgae. In this review, application of electric field-based techniques and recent advances of using electrical pretreatments on microalgae cell focusing on pulsed electric field, electrolysis, high voltage electrical discharges and moderate electric field are reviewed. In addition, the emerging techniques integrating electrolysis with liquid biphasic flotation process as promising downstream approach is discussed. This review delivers broad knowledge of the present significance of the application of these methods focusing on the development of electric assisted biomolecules extraction from microalgae.

Description: Coastal communities, knowingly or otherwise, rely on seagrasses for their livelihood, recreation and food source, among other services. However, despite its importance, seagrasses are not receiving similar attentions with its adjacent ecosystems, the mangroves, and coral reefs. Because of their role in climate change mitigation, seagrasses along with mangroves and salt marshes (the blue carbon ecosystems) are gaining attention recently. This preliminary study investigates the perception of coastal communities in Eastern Samar, Philippines on seagrasses. The results of the survey show that there is a level of high awareness among respondents to seagrass ecosystem services. Despite that, however, utilization remains low. The level of awareness varies on the type of ecosystem service; for instance, locals have a high awareness of provisioning services while low awareness of cultural services. The survey also included the perceived threats to seagrasses, where damages caused by natural disturbances are identified as the most concerning threat. This may be due to the geographic location of the sites that are frequented by typhoons. The perception potentially indicates depleted resources brought about by mismanagement or overlooking this natural resource. The results provide a more contextualized understanding on how local communities are aware of and interacting with, or the lack thereof, seagrass ecosystems. This could aid local government units (LGUs) and conservation groups in the area to craft practicable and sustainable management plans and threat-specific solutions.

Description: Simulating complex physical systems often involves solving partial differential equations (PDEs) with some closures due to the presence of multi-scale physics that cannot be fully resolved. Therefore, reliable and accurate closure models for unresolved physics remains an important requirement for many computational physics problems, e.g., turbulence simulation. Recently, several researchers have adopted generative adversarial networks (GANs), a novel paradigm of training machine learning models, to generate solutions of PDEs-governed complex systems without having to numerically solve these PDEs. However, GANs are known to be difficult in training and likely to converge to local minima, where the generated samples do not capture the true statistics of the training data. In this work, we present a statistical constrained generative adversarial network by enforcing constraints of covariance from the training data, which results in an improved machine-learning-based emulator to capture the statistics of the training data generated by solving fully resolved PDEs. We show that such a statistical regularization leads to better performance compared to standard GANs, measured by (1) the constrained model's ability to more faithfully emulate certain physical properties of the system and (2) the significantly reduced (by up to 80%) training time to reach the solution. We exemplify this approach on the Rayleigh-Benard convection, a turbulent flow system that is an idealized model of the Earth's atmosphere. With the growth of high-fidelity simulation databases of physical systems, this work suggests great potential for being an alternative to the explicit modeling of closures or parameterizations for unresolved physics, which are known to be a major source of uncertainty in simulating multi-scale physical systems, e.g., turbulence or Earth's climate.

Description: Microalgae are a rich source of natural bioactive compounds, e.g. astaxanthin, β-carotene, lutein, and fatty acids (FAs), that are currently in high demand in the market. Conventional extraction methods often produce adverse effects on some of these compounds. Replacing conventional extraction methods with more efficient advanced green technologies that offer greater extracts purity and low environmental impact is therefore a challenging and sought-for target. This review is a comprehensive overview of supercritical fluid (SCF) extraction processes, including the latest research on the extraction of bioactive compounds from microalgae biomass and their benefits on human health. In addition, the role of key operating parameters on the selectivity of various compounds is discussed. This study provides useful knowledge that can productively contribute to the future development of SCF-based extraction technologies on an industrial scale.

Description: Aging entails an irreversible deceleration of physiological processes, altered metabolic activities, and a decline of the integrity of tissues, organs, and organ systems. The accumulation of alterations in the genetic and epigenetic spaces has been proposed as an explanation for aging. They result, at least in part, from DNA replication and chromosome segregation errors due to cell division during development, growth, renewal, and repair. Such deleterious alterations, including epigenetic drift, irreversibly accumulate in a stepwise, ratchet-like manner and reduce cellular fitness, similar to the process known as Muller’s ratchet. Here, we revisit the Muller’s ratchet principle applied to the aging of somatic cell populations and discuss the implications for understanding the origins of senescence, frailty, and morbidity.

Description: Natural cycles in the seawater partial pressure of carbon dioxide (CO2) in the Gulf of Maine, which vary in surface waters from ~250 to 550 µatm seasonally, provide an opportunity to observe how the life cycle and phenology of the shelled pteropod Limacina retroversa responds to changing food, temperature and carbonate chemistry conditions. Distributional, hydrographic, and physiological sampling suggest that pteropod populations are located in the upper portion of the water column (0–150 m) with a maximum abundance above 50 m. Gene expression and shell condition measurements show that the population already experiences biomineralization stress in the winter months when measured aragonite saturation state was at a seasonal low (though slightly oversaturated), reinforcing the usefulness of this organism as a bio-indicator for pelagic ecosystem response to ocean acidification. There appear to be two reproductive events per year with one pulse timed to coincide with the spring bloom, the period with highest respiration rate, fluorescence, and pH, and a second more extended pulse in the late summer and fall when saturation states remain high and fluorescence begins to decline. During the fall there is transcriptomic evidence of lipid storage for overwintering, allowing the second generation to survive the period of low food and aragonite saturation state. Based on these observations we predict that in the future pteropods will likely be most vulnerable to changing CO2 regionally during the fall reproductive event when CO2 concentration already naturally rises and when there is the added stress of generating lipid stores.

Description: We use numerical simulations on petrographically characterized thin-section images to predict three-dimensional elastic compressibility of sandstones. We predict two key statistics of compressibility curves measured under uniaxial boundary conditions in a laboratory - i) minimum compressibility at 1500 psi or 10 MPa depletion stress, and ii) maximum compressibility. A new Digital Rock workflow was developed for predicting compressibility based on the simulation of stress field using a segmented two-dimensional thin-section image. We also propose linear and non-linear relationships of log base 10 (compressibility) with in-situ porosity that can be used for compressibility prediction in the absence of laboratory measurements or two-dimensional images. Based on the results of application of the proposed relationships on samples from different fields with laboratory measurements, we conclude that the best prediction for minimum compressibility is obtained using the Digital Rock workflow and the best prediction for maximum compressibility is obtained using the proposed non-linear relationship using in-situ porosity. The range of compressibility values given by the difference between maximum and minimum compressibility predicted using the proposed methods can be used in making better informed economic decisions in field development planning.

Description: Pteropods are holopelagic marine snails and slugs that are of particular interest to science due to their role in marine food webs, global carbon cycle and their potential sensitivity to ocean change. Due to their pelagic, often exclusively offshore occurrence, samples are difficult to obtain, resulting in a lack of knowledge about their physiology, ecology, anatomy, geographical ranges, phylogenetic relationships and reproductive biology. Despite a recent increase in interest surrounding pteropod taxonomy, many evolutionary uncertainties remain due to limited taxon sampling and inavailability of molecular vouchers, in particular for the lesser investigated groups Pseudothecosomata and Gymnosomata. The Northwest Pacific Ocean is one of the least investigated areas for pteropods and in the adjacent semi-enclosed Sea of Okhotsk basin, current knowledge is restricted to the epipelagic zone. We summarize results from plankton hauls (from up to 5900 m depth) conducted during the joint German/Russian SokhoBio and KuramBio II cruises to the Sea of Okhotsk and the Kuril-Kamchatka-Trench region. This study presents an integrative taxonomic overview of six pteropod species identified by detailed morphological methods, including serial semithin sectioning, µCT and SEM scanning supported by multimarker (COI, 28S, and H3) genetic barcoding. We found four species of Gymnosomata slugs (Clione limacina, Clione okhotensis, Notobranchaea grandis and Thliptodon sp.), three species of Euthecosomata snails (Limacina helicina and two genetically delimited Clio spp.) and one shelled pseudothecosome species that is probably new to science (Peracle n. sp.). Multilocus phylogenetic analyses support monophyly of major traditional groups such as Pteropoda, Thecosomata, Pseudothecosomata and Gymnosomata. Micro-CT scanning was applied for the first time on pteropod soft bodies, allowing direct comparison between detailed anatomical peculiarities and molecular barcodes of the respective species. Furthermore, taxonomic positions, geographical ranges and potential dispersal barriers are discussed, with implications for future biodiversity comparisons. This study serves as a solid foundation for monitoring pteropods in a changing ocean.

Description: Hybrid chemical compounds formed by conjugation of two or more bioactive molecules have shown wide variety of applications in biology, microelectronics as well as material sciences. In particular, the conjugates of steroid framework are known to have broad biological activity profile due to their ability to penetrate the biomembranes and bind to specific hormone receptors. Among the various conjugates of steroids, Steroid Amino Acid Conjugates (SAACs) are attractive because of the possibility of fine tuning of the amphiphilicity with position, orientation and nature of amino acids. The structural details, applications, mechanistic insights and their diverse pharmacological as well as other physicochemical properties of several SAACs are summarized in the present review. This review provides better insight for medicinal chemists to design and explore such novel conjugates which can be used as lead structures in the future drug discovery or as probes to understand the complex biological system.

Description: Microalgal oils are considered an important source of industrially valuable oleochemicals with significant applications ranging from the energy to pharmaceutical sectors. Industrial production of microalgal oil is emerging rapidly; however, the high cost associated with downstream processes may constrain this process. Oils are accumulated intracellularly in oleaginous microalgae in the form of lipid droplets, which in turn require cell wall disruption followed by extraction in order to recover them. Disruption of the microalgal cell is very challenging owing to its distinctive features like high water content, hard cell wall, presence of algaenan, and sporopollenin like biopolymers that in turn create hurdles in efficient extraction of lipids. Various conventional pretreatment methods have been explored to rupture the cellular integrity of microalgal cells to enhance lipid extraction, and each method has certain advantages and disadvantages. Supercritical fluid extraction is the oldest technique for the extraction of valuable compounds from microalgae and is considered an alternative to conventional solvent extraction methods. It has several advantageous features such as being free from organic solvents (and their disposal), environment-friendly, and operating at a mild range of temperature (40–80°C). CO2 is considered to be an ideal supercritical fluid due to its non-toxic, non-flammable, and lipophilic nature. In this chapter, use of supercritical carbon dioxide extraction of lipids from microalgae is discussed and compared with other available lipid extraction methods.

Description: Cell disruption is regarded as an indispensable pretreatment step before the extraction of microalgae with biomineralized cell walls. Here, two typical microalgae—diatom Chaetoceros gracilis (C. gracilis) and coccolithophore Pleurochrysis carterae (P. carterae)—covered by “hard” biomineralized cell walls were used as starting materials for lipid extraction using liquefied dimethyl ether (DME) without any pretreatment such as drying or cell disruption. The liquefied DME extraction experiments were performed at 25 °C and 0.59 MPa using a semi-continuous, flow-type system. The results of the yield, elemental composition, molecular weight distribution, fatty acid composition, and trace element composition indicated that the performance of liquefied DME extraction was similar to that of Bligh–Dyer extraction and better than that of hexane Soxhlet extraction, despite the latter two methods requiring pre-drying and cell disruption processes. It was also proven that the cell wall of microalgae would not affect lipid extraction of liquefied DME, thereby the liquefied DME extraction method is suitable for extracting lipids from microalgae with biomineralized cell walls. Besides, the lipids extracted by liquefied DME can be further used for biodiesel production.

Description: In recent years, metagenomic strategies have been widely used to isolate and identify new enzymes from uncultivable components of microbial communities. Among these enzymes, various lipases have been obtained from metagenomic libraries from different environments and characterized. Although many of these lipases have characteristics that could make them interesting for application in biocatalysis, relatively little work has been done to evaluate their potential to catalyze industrially important reactions. In the present article, we highlight the latest research on lipases obtained through metagenomic tools, focusing on studies of activity and stability and investigations of application in biocatalysis. We also discuss the challenges of metagenomic approaches for the bioprospecting of new lipases.

Description: There are no effective therapies for achondroplasia. An open-label study suggested that vosoritide administration might increase growth velocity in children with achondroplasia. This phase 3 trial was designed to further assess these preliminary findings. Methods This randomised, double-blind, phase 3, placebo-controlled, multicentre trial compared once-daily subcutaneous administration of vosoritide with placebo in children with achondroplasia. The trial was done in hospitals at 24 sites in seven countries (Australia, Germany, Japan, Spain, Turkey, the USA, and the UK). Eligible patients had a clinical diagnosis of achondroplasia, were ambulatory, had participated for 6 months in a baseline growth study and were aged 5 to less than 18 years at enrolment. Randomisation was done by means of a voice or web-response system, stratified according to sex and Tanner stage. Participants, investigators, and trial sponsor were masked to group assignment. Participants received either vosoritide 15·0 μg/kg or placebo, as allocated, for the duration of the 52-week treatment period administered by daily subcutaneous injections in their homes by trained caregivers. The primary endpoint was change from baseline in mean annualised growth velocity at 52 weeks in treated patients as compared with controls. All randomly assigned patients were included in the efficacy analyses (n=121). All patients who received one dose of vosoritide or placebo (n=121) were included in the safety analyses. The trial is complete and is registered, with EudraCT, number, 2015-003836-11. Findings All participants were recruited from Dec 12, 2016, to Nov 7, 2018, with 60 assigned to receive vosoritide and 61 to receive placebo. Of 124 patients screened for eligibility, 121 patients were randomly assigned, and 119 patients completed the 52-week trial. The adjusted mean difference in annualised growth velocity between patients in the vosoritide group and placebo group was 1·57 cm/year in favour of vosoritide (95% CI [1·22–1·93]; two-sided p〈0·0001). A total of 119 patients had at least one adverse event; vosoritide group, 59 (98%), and placebo group, 60 (98%). None of the serious adverse events were considered to be treatment related and no deaths occurred. Interpretation Vosoritide is an effective treatment to increase growth in children with achondroplasia. It is not known whether final adult height will be increased, or what the harms of long-term therapy might be.

Description: Biofouling is a challenge in global sea-based salmon farming. Norway's salmon-growing industry relies primarily on copper-based antifouling coatings. However, copper is an increasingly recognised environmental hazard, and there is a need to develop alternative antifouling products to prevent biofouling in marine aquaculture. Using field experiments, this study compared the efficacy of six novel antifouling coatings for fish farm nets (two with reduced copper content, three with alternative biocides and one biocide-free coating) against a popular commercial copper coating and uncoated samples. The performance of one of the new coatings with lower copper content was more similar to the commercial copper control while the rest were colonised by biofouling faster and/or at higher abundances. However, none of the tested products were able to prevent biofouling entirely, underlining the importance of the search for alternative and improved antifouling technologies.

Description: Seagrass meadows are important productive ecosystems; during the Summer period in touristic beaches, such as those located in the high Adriatic coast, seagrasses are removed from the shoreline and disposed in landfill. This study investigated anaerobic digestion potential of beach-cast seagrass wrack, considering the physicochemical characteristics of the substrate and analysing heavy metal presence in the digestate, with the aim of transporting the material to local wastewater treatment plants to increase biogas yield from excess sludge anaerobic digestion. The methane production obtained from seagrass wrack was compared with three theoretical models. Seagrass wrack had a good methane potential of 103.1–262.3 NmL CH4/g Volatile Solids (VS), depending on substrate humidity and applied inoculum-to-substrate ratio. Predictive models, based on elemental composition and proximate analysis, successfully estimated methane yields; heavy metal concentration in digestate was low, boosting for digestate agricultural reuse. A simplified energy analysis revealed that transport to local wastewater treatment plants and use in anaerobic digestion process would provide up to 245,000 Nm3/y of methane, with an estimated economic income of 33,500–193,300 €/y, considering local seagrass production (1,465–8,454 t/y). Actual yearly costs sustained by beach management company for landfill disposal was about 117,200–676,320 €/y. Seagrass reuse in local digesters would compensate for the lack of excess sludge encountered during the cold season, allowing the digester to operate more continuously, increasing biogas production and reducing plant energy need.

Description: The analysis of more than 400 papers found in the literature on Sargassum biosorption has shown the existence of more than 700 equilibrium entries corresponding to data at different temperature and pH conditions. The following ten single metals: Cd, Co, Cr(III, VI), Cu, Fe, Hg, La, Ni, Pb, and Zn, are the main focus of most of the equilibrium data (507) in more than half of the studied references. The studies reflecting the interaction of nine of these metals with Sargassum sp. is described and analyzed. The use of Langmuir equation, the effect of temperature and pH on sorption is critically reviewed. In addition, we also analyze all the data available on elemental chemical composition of native Sargassum. These data reflect the interaction of this kind of marine biomass with nine of the metals mentioned above, which are present in seawater worldwide.

Description: Six new compounds including two azaphilones, lunatoic acids D–E (1, 2), three isocoumarins, lunatinins B–D (3-5), and one α-pyrone derivative, lunatinin E (6), as well as four known ones, lunatoic acid A (7), lunatinin (8), penicipyran D (9) and chaetoquadrin F (10) were isolated from the rice medium of the gut fungus Paraphaeosphaeria sp. XZD2-1. Their planar structures were elucidated by analysis of 1D and 2D NMR as well as HRESIMS spectroscopic data. The absolute configurations of compounds 1-3 were assigned by experimental and calculated ECD data and an ester hydrolysis reaction. Compounds 4 and 5 were a pair of enantiomeric excess mixture. Structure of compound 6 was further confirmed by comparing optical rotation with known compounds according to literature. The antimicrobial activity and cytotoxicity of compounds 1-10 were examined.

Description: As the frequency and intensity of storms increase, a growing need exists for resilient shore protection techniques that have both environmental and economic benefits. In addition to producing seafood, aquaculture farms may also provide coastal protection benefits either alone or with other nature-based structures. In this paper, a generalized three-layer frequency dependent theoretical model is derived for random wave attenuation due to presence of biomass within the water column. The biomass can be characterized as submerged, emerged, suspended and floating canopies that can consist of natural aquatic vegetation with potential aquaculture systems of kelp or mussels. The present analytical solutions can reduce to the solutions by Mendez and Losada (2004), Chen and Zhao (2012) and Jacobsen et al. (2019) for submerged rigid aquatic vegetation. The present theoretical model incorporates the motion of these canopies using a cantilever-beam model for slender components and a buoy-on-rope model for elements with concentrated mass and buoyancy. Analytical results are compared with existing laboratory and field datasets for submerged and suspended canopies. The theoretical model was then used (in a case study at a field site in Northeastern US) to investigate the capacity of suspended mussel farms with submerged aquatic vegetation (SAV) to dissipate wave energy during a recent storm event. Compared to a dense SAV meadow in shallower water, the suspended aquaculture farms more effectively attenuate random waves with a smaller peak period and the higher frequency components of wave spectrum. The performance of suspended aquaculture farms is less affected by water level changes due to tides, surge and sea level rise, while the wave attenuation performance of SAV decreases with increasing water level due to decreased wave motion near the sea bed. Incorporating suspended aquaculture farms offshore significantly enhance the coastal protection effectiveness of SAV-based living shorelines and extend the wave attenuation capacity over a wider wave period and water level range. The combination of suspended aquaculture farms and traditional living shorelines provides a more effective nature-based coastal defense strategy than the traditional living shorelines alone.

Description: Application of polyester-degrading enzymes should be considered as an eco-friendly alternative to chemical recycling due to the huge plastic waste disposal nowadays. Many hydrolases from several fungi and bacteria have been discovered and successfully evaluated for their activity towards different aliphatic polyesters (PHA, PBS, PBSA, PCL, PLA), aromatic polyesters (PET, PBT, PMT) as well as their co-polyesters (PBST, PBAT, PBSTIL). This revision gives an up-to-date overview on the main biochemical features and biotechnological applications of those reported enzymes which are able to degrade polyester-based plastics, including different microbial polyester depolymerases, esterases, cutinase-like enzymes and lipases. Summarized information includes available protein sequences with the corresponding accession numbers deposited in NCBI server, 3D resolved structures, and data about optimal conditions for enzymatic activity and stability of many of these microbial enzymes that would be helpful for researchers in this topic. Although screening and identification of new native polyester hydrolases from microbial sources is undeniable according to literature, we briefly highlight the importance of the design of improved enzymes towards recalcitrant aromatic polyesters through different approaches that include site-directed mutagenesis and surface protein engineering.

Description: The subpopulation of Atlantic cod, Gadus morhua, in the eastern part of the Baltic Sea has experienced a significant increase in infections with anisakid nematode larvae of the species Contracaecum osculatum sensu lato (s.l.) since the year 2000. The life cycle of the parasite includes seals and especially the grey seal, Halichoerus grypus, as final hosts, carrying the adult nematodes in the stomach, crustaceans (copepods, amphipods) as first intermediate hosts and various fish species (clupeids, sandeel) including cod as second intermediate/paratenic hosts. Cod with a body length below 28 cm are generally non-infected but experience increasing infection levels when they switch to a piscine diet (infected intermediate/paratenic hosts). We present an overall frequency distribution analysis of worms in 166 cod (body length 30–49 cm) collected in the spawning area over the last 5 years. It shows a fit to the negative binomial distribution, a prevalence of infection of 89.8%, a mean intensity of 29.3 parasites per fish (range 1–377) and a variance/mean ratio of 59.2 (≫1), indicating overdispersion. We present measurements of the adult Contracaecum osculatum (s.l.) specimens in the seal stomach and show that the parasites reach a maximum length of 6.6 cm (females) and 5.8 cm (males). L3s in sprat have a total length from 1to 11 mm whereas the larvae in cod liver are 3–27 mm. A decreasing mean worm length associated with high worm densities in cod (number of nematodes per liver) was recorded. Possible explanations might include timing of feeding on infected intermediate/paratenic hosts, intraspecific competition (crowding) between larvae in cod and host responses (indicated by a significant antibody production in cod against C. osculatum (s.l.) antigens). A significant negative correlation between infection intensity and muscle mass of cod was found, suggesting parasite-induced down-regulation of growth factors in cod.

Description: Despite their critical role as the main energy pathway between phytoplankton and fish, the functional complexity of zooplankton is typically poorly resolved in marine ecosystem models. Trait-based approaches—where zooplankton are represented with functional traits such as body size—could help improve the resolution of zooplankton in marine ecosystem models and their role in trophic transfer and carbon sequestration. Here, we present the Zooplankton Model of Size Spectra version 2 (ZooMSSv2), a functional size-spectrum model that resolves nine major zooplankton functional groups (heterotrophic flagellates, heterotrophic ciliates, larvaceans, omnivorous copepods, carnivorous copepods, chaetognaths, euphausiids, salps and jellyfish). Each group is represented by the functional traits of body size, size-based feeding characteristics and carbon content. The model is run globally at 5° resolution to steady-state using long-term average temperature and chlorophyll a for each grid-cell. Zooplankton community composition emerges based on the relative fitness of the different groups. Emergent steady-state patterns of global zooplankton abundance, biomass and growth rates agree well with empirical data, and the model is robust to changes in the boundary conditions of the zooplankton. We use the model to consider the role of the zooplankton groups in supporting higher trophic levels, by exploring the sensitivity of steady-state fish biomass to the removal of individual zooplankton groups across the global ocean. Our model shows zooplankton play a key role in supporting fish biomass in the global ocean. For example, the removal of euphausiids or omnivorous copepods caused fish biomass to decrease by up to 80%. By contrast, the removal of carnivorous copepods caused fish biomass to increase by up to 75%. Our results suggest that including zooplankton complexity in ecosystem models could be key to better understanding the distribution of fish biomass and trophic efficiency across the global ocean.

Description: Mitigating human contributions to climate change is a highly debated topic, as it becomes evident that many nations do not adhere to optional reductions in global emission. Substantial research is taking place into negative carbon technologies that actively reduce the amount of atmospheric carbon dioxide (CO2) via greenhouse gas removal (GGR). Various GGR methods have been proposed, from reforestation to ocean fertilisation. This article discusses advantages of an approach based on enhanced input of tephra to the ocean, to increase the drawdown of atmospheric CO2. Natural addition of tephra to the ocean results in preservation of enhanced organic matter in sediment. Hence, augmenting its delivery should raise the level of sequestration. Calculations indicate that offshore tephra addition could sequester 2750 tonnes of CO2 per 50,000 tonnes of ash delivered (a typical bulk carrier’s capacity). The cost is estimated as ∼$55 per tonne of CO2 sequestered and is an order of magnitude cheaper than many proposed GGR technologies. Further advantages include: tephra addition is simply an augmentation of a natural Earth process, it is a low technology approach that requires few developments, and it may sequester carbon for thousands of years. Hence, offshore tephra addition warrants further investigation to assess its viability.

Description: Subsurface-intensified anticyclones are ubiquitous in the ocean, yet their impact on the large-scale transport of heat, salt and chemical tracers is poorly understood. These submesoscale coherent vortices (SCVs) can trap and advect waters thousands of kilometers away from the formation region, providing a transport pathway that is unresolved by low-resolution Earth System Models. However, knowledge of the importance of these eddies for the large scale circulation is hindered by the lack of systematic observations. Here, we take advantage of the global network of Argo floats to identify occurrences of these eddies, which appear as weakly stratified anomalous water masses with Gaussian-shaped vertical structures. We develop a general algorithm to detect subsurface eddies that have propagated away from their source region, and apply it to the database of Argo float profiles, resulting in roughly 4000 detections from more than 20 years of observations. We further group detections into regional populations to identify hot-spots of generation and mechanisms of formation. Analysis of regional SCV statistics reveals important sites of SCV generation in Eastern Boundary Upwelling Systems, marginal sea overflows, and mode water formation regions along major open-ocean fronts. Because of the heat and salt anomaly contained within their cores, SCV could leave a significant imprint on the hydrographic properties of water masses in regions of high SCV density.

Description: Used during an oil spill to minimise the formation of an oil slick, dispersants have negative biological effects on marine model organisms. However, no study has investigated the impacts of dispersants on adult sponge individuals. Here, we examine the effects of water accommodated oil fraction (WAF - oil in seawater), chemically enhanced WAF (CEWAF - oil and dispersant in seawater) and Benzo[A]Pyrene on sponge Halichondria panicea at physiological and molecular levels. Sponge clearance rate decreased sharply when exposed to WAF and CEWAF but the oil loading at which the clearance rate was reduced by 50% (ED50) was 39-fold lower in CEWAF than in WAF. Transcriptomic analysis revealed a homogenous molecular response with the greatest number of differentially expressed genes identified in CEWAF samples (1,461 genes). Specifically, genes involved in stress responses were up-regulated. This study presents evidence that the use of dispersants should be considered carefully in areas where sponges are present.

Description: This study evaluated the application of a Halobacteriovorax isolated from water of the Adriatic Sea (Italy) in controlling V. parahaemolyticus in mussels (Mytilus galloprovincialis). Two 72 h laboratory-scale V. parahaemolyticus decontamination experiments of mussels were performed. The test microcosm of experiment 1 was prepared using predator/prey free mussels experimentally contaminated with Halobacteriovorax/V. parahaemolyticus at a ratio of 103 PFU/105 CFU per ml, while that of experiment 2 using mussels naturally harbouring Halobacteriovorax that were experimentally contaminated with 105 CFU per ml of V. parahaemolyticus. For experiment 1, was also tested a control microcosm only contaminated with 105 CFU per ml of V. parahaemolyticus.. Double layer agar plating and pour plate techniques were used to enumerate Halobacteriovorax and V. parahaemolyticus, respectively. 16 S rRNA analysis was used to identify Halobacteriovorax. For both experiments in the test microcosm the concentration of prey remained at the same level as that experimentally added, i.e. 5 log for the entire analysis period. In experiment 1, V. parahaemolyticus counts in mussels were significantly lower in the test microcosm than the control with the maximum difference of 2.2 log at 24 h. Results demonstrate that Halobacteriovorax can modulate V. parahaemolyticus level in the mussels. The public impact of V. parahaemolyticus in bivalves is relevant and current decontamination processes are not always effective. Halobacteriovorax is a suitable candidate in the development of a biological approach to the purification of V. parahaemolyticus in mussels.

Description: The ctenophore Mnemiopsis leidyi, ranking among the 100 most damaging bioinvaders in the world, is a major predator of zooplankton, known to alter the biodiversity and functioning of the ecosystems in which it has been introduced. This first survey on the trophic relationships of M. leidyi in a Mediterranean lagoon (Berre, South of France) was performed through stable isotope analyses. Carbon and nitrogen isotope composition was used (1) to determine the types of prey ingested by this ctenophore and (2) the influence of individual size on its isotope composition, and (3) to make assumptions to explore its trophic relationships with the native jellyfish Aurelia sp.. The two gelatinous species ingested mainly (79% to 97% of the diet) planktonic prey (copepods, cirriped nauplii, gastropod larvae and cladocerans), but also preyed upon benthic organisms (mainly harpacticoid copepods and the amphipod Monocorophium insidiosum) in lower proportions (2.5% to 21%). Size-related changes in M. leidyi diet were evidenced with an increase in trophic level and benthic prey consumption in the larger individuals. These two gelatinous organisms probably play an important and underestimated role in the benthic–pelagic​ coupling in coastal lagoons by transferring benthic organic matter to the pelagic food webs.

Description: When determining vertical velocity spectra from temperature time series and the mean vertical temperature gradient, restrictions may arise friom the existence of fine-structre. Phillips (1971) and Garrett and Munk (1971_ have shown that the fine-structure contamination of internal gravity wave spectra can be written as a function of some statistical properties of the internal wave field and the vertical wave number spectrum of the fine-structure. A consistent set of current and temperature data was obtained during an experiment at Site D to study this problem. The wave number spectrum of the vertical temperature fine-structure and the apparent frequently spectrum of internal waves are determined from these data. In contrast to the asasumptions in the above models, our fine-structure data imply a wave number spectrum proportional to (wave number)−3 in the range which is important here. Using the above set of data, a model is suggested to describe the effect of fine-structure on vertical velocity spectra computed with the mean vertical temperature gradient. It indicates a maximum fine-structure contamination of the true frequency spectrum of internal gravity waves in the middle of the internal wave band, with less contamination at low and high frequencies.

Description: A new equation for the speed of sound in sea water has been developed with validity not only for realistic combinations of the parameters salinity, temperature, and pressure, but with extension to pure water as well. This new equation, referred to as NRL II, has a standard deviation of 0.05 m/sec. Tables are presented comparing calculations using this new model to each of eight earlier equations. Graphs are also included indicating approximate corrections that could be applied to existing sound speed profiles, but it is recommended that such profiles be recalculated and new ones obtained according to NRL II.

Description: An experiment is described which was aimed at testing assumptions and predictions of the internal wave model suggested by Garrett and Munk (1972). Two moorings were set at a depth of 2660 m with a horizontal separation of 920 m only. The results of current and temperature measurements on these moorings indicate that the field of motion is probably horizontally isotropic in the inertio-gravitational wave band. The limiting frequency for horizontal coherence is three times the frequency predicted by the theoretical model. The phase of the vertical coherence is stable over a wide frequency range and the coherence decreases towards higher frequencies. This may be due to coherent motion contaminated by uncorrelated noise at high frequencies. The results are basically in agreement with the theoretical model when taking a number of modes below 10.

Description: Attraction of the polychaete Capitella capitata to different types of substrates has been investigated in the laboratory. Some observations on the reprcduction, development, and breeding behaviour, as well as on the reaction of the species to the factors sewage concentration, light, and current are reported.

Description: In einer Vertiefung der Kieler Forde, dem sogenannten Baggerloch, kommt es im Sommer und Herbst zu mehrwöchigen Stagnationsperioden, in denen im Wasser Schwefelwasserstoff auftritt. Es konnte nachgewiesen werden, daB die Bildung von Schwefelwasserstoff hauptsächlich durch bakterielle Sulfatreduktion (Desulfurikation) in der obersten Sedimentzone erfolgt. Sie wird vor allem durch Desulfovibrio desulfuricans bewirkt, während Desulfotomaculum nigrificans dabei allenfalls eine sehr untergeordnete Rolle spielt. Entsprechend der verhältnismäßig geringen Menge von schwefelhaltigen Aminosäuren im Wasser und Sediment des Baggerloches dürfte der Anteil des bei der Eiweißfäulnis freigesetzten H2S nicht sehr bedeutend sein. Die Zahl der desulfurizierenden Bakterien lag 1967 und 1968 während der Stagnationsperioden in dem obersten Zentimeter des Sediments bei 100OOO im cm3 - dagegen im Wasser stets unter 20 im ml. Die Anzahl der schwefeloxydierenden Bakterien war gering und lag in der Regel unter 5 im ml Wasser. Es handelt sich dabei vorwiegend um Thiobacillen. Fadige Schwefelbakterien (Beggiatoa, Thiothrix) sind zwar vorhanden - doch konnte keine Rasenbildung auf der Sedimentoberfläche beobachtet werden. Die bakterielle Oxydation von H2S ist demnach nicht sehr groß. Die chemische Oxydation und auch die Sulfidbildung erfolgen im wesentlichen in der Grenzzone zwischen H2S- und O2-haltigem Wasser.

Description: Die mikrobielle Aktivität sowie die Saprophytenzahl in Abhängigkeit vom Salzgehalt wurden in abwasserbelastetem Flußwasser, dessen Salzkonzentration durch Zugabe von NaCl künstlich erhöht worden war, gemessen. Daneben fanden Untersuchungen über die Salzansprüche der 10 häufigsten Bakterienstämme der Probe statt. Außerdem wurde das Wachstum der natürlichen Bakterienpopulationen bei unterschiedlichen Salzkonzentrationen nach Zugabe von Nährstoffen bestimmt. Es zeigte sich, daß die Aktivität und die Zahl der Mikroorganismen durch die Erhöhung des Salzgehaltes stark zurückgingen. Nur eine geringfügige Adaptation konnte festgestellt werden. Nach Zugabe von Nährstoffen trat dagegen eine schnelle Umstellung der Population ein. Die Untersuchungen ergaben, daß die mit dem Flußwasser eingeschwemmten Süß- und Abwasserbakterien nur eine geringe Rolle bei der Selbstreinigung der Küstengewässer spielen. The microbial activity as well as the number of saprophytic bacteria in relation to the salt concentration was measured. The measurements were performed in river water, the salt concentration of which was raised by the addition of NaCl. Also the salinity requirements of the 10 most frequently occurring bacteria were determined. Furthermore the growth rate of the natural bacteria populations in relation to the salt concentration was measured after the addition of nutrients. The activity and the number of bacteria were strongly affected in a negative manner with increasing salt concentrations. Only a slight adaptation could be found. With higher amounts of nutrients, rapid changes in the population were observed. The results showed that the microbial populations carried into the sea by the rivers and sewage effluents can play only a minor role in the self-purification of the coastal waters.

Description: 15.2% of 541 examined cod (Gadus morhua L.) caught in the fjord of Kiel carried a macroscopically visible infection of Ichthyosporidium hoferi (= Ichthyophonus h.). The fungus was found in the liver, heart, spleen, and body-muscles. Infected cod showed up to 30.7% underweight. The condition-factor of infected fish lay significantly below that of healthy ones. Von 541 untersuchten Dorschen (Gadus morhua L.) aus der Kieler Förde waren 15,2% makroskopisch erkennbar mit Ichthyosporidium hoferi (= Ichthyophonus h.) befallen. Der Pilz wurde in Leber, Milz, Herz und Körpermuskulatur nachgewiesen. Infizierte Tiere zeigten bis 30,7% Untergewicht. Der Konditionsfaktor kranker Fische lag signifikant unter dem gesunder Tiere.

Description: Es wird ein seit einigen Jahren in der Gewässermikrobiologie eingeführtes Verfahren zur Bestimmung des "Heterotrophen Potentials" beschrieben. Die Vor- und Nachteile dieser Methode werden diskutiert. Ihre vielfältigen Anwendungsmöglichkeiten werden an Hand einiger Beispiele dargestellt. A method which has been used during the last few years to determine the "relative heterotrophic potential" in aquatic environments is discribed. The advantages and disadvantages involved are discussed. Some examples of the applications of this method are also given.

Description: Von März bis August wurde zehnmal bei fünf Stationen in der Schlei die Besiedlung der Copepoden durch Myoschiston centropagidarum untersucht. Für den häufigsten Copepoden, Eurytemora affinis, wurde aus der Verteilung der Entwicklungsstadien und der Dauer der einzelnen Stadien der Entwicklungszustand der Population rekonstruiert. Zusätzlich wurde die Eiproduktion und die Änderung der Körpergröße untersucht. Für Acartia tonsa, die im Sommer Eurytemora ablöste, wurde nur die Verteilung der Stadien ermittelt. Die Besiedlung durch Myochiston wurde für jedes Stadium bestimmt. Zum Verständnis der Besiedlung reichte die vorgefundene Populationsstruktur nicht aus. Auf den beiden Stationen mit dem geringsten Salzgehalt, wo die Copepodenpopulationen sich auf Grund der Strömungsverhältnisse ungestört entwickelten, konnte die Besiedlung klar aus der Vorgeschichte der Copepodenpopulation abgeleitet werden. Eine optimale Besiedlung ergab sich, wenn sich eine Copepodengeneration ihrem Ende näherte und kurz nach dem Ende einer Generation. Myoschiston centropagidarum ist spezifisch für die beiden dominanten Arten Eurytemora affinis und Acartia tonsa und kann deshalb während des ganzen Jahres seinen Lebensraum besiedeln. From March to August samples were taken on ten occasions at five stations in the Schlei to investigate the infestation of the copepods by Myoschiston centropagidarum. For the most abundant form Eurytemora affinis the history of the population was computed from the distribution and the life span of the different developmental stages. The egg production and change in size were measured. For Acartia tonsa, which replaced Eurytemora during summer, only the distribution of the different stages was determined. The degree of infestation with Myoschiston was measured for each stage. However, the determined population structure was not sufficient to explain the infestation. At the two innermost stations, where the populations were not disturbed by currents, the infestation could be related to the history of the copepod populations. The most epizoes could be found at the end of a generation or the beginning of a new one. Myoschiston centropagidarum is specific to the two dominant copepods Eurytemora affinis and Acartia tonsa and can therefore be found all the year round.

Description: This article describes and discusses a new method for the fluorescence microscopic examination of bacteria on Nuclepore membrane filters. The bacteria, which have been concentrated by filtration, are stained with a solution of acridine orange. Then the filters are destained with isopropyl alkohol and xylene. This method makes it possible to recognize small bacteria and to distinguish them from detritus. Dieser Beitrag beschreibt und diskutiert eine neue Methode zur fluoreszenzmikroskopischen Untersuchung von Bakterien auf Nuclepore-Membranfiltern. Die durch Filtration angereicherten Keime werden mit einer Akridinorange-Lösung gefärbt. AnschlieBend werden die Filter mit Isopropanol und Xylol entfärbt. Diese Methode ermöglicht es, auch kleine Bakterien zu erkennen und sie von Detritus zu unterscheiden.

Description: 1.1. A percolator was constructed to measure continously metabolic processes in sediments. A continous flow of water penetrates the sediment. Oxygen can be excluded. A continous polarographic control is possible or a control with enzyme electrodes. Gases evolved by metabolism can be trapped. It was attempted to discriminate bacterial and purely enzymatic processes (free enzymes) by addition of chloroform or toluene, both of which will kill bacteria. The attempt was unsuccessful. 1.2. Enzyme electrodes were constructed as a probe for sediments, for the percolator, and for the free water. The enzyme electrodes permit the determination of the ratios of inorganic phosphorus/organic phosphorus, urea/ammonia, glycosidically bound glucose/free glucose. The enzyme is coupled to a diazotized anilin resin which is fixed on a metal electrode as a thin layer. The potentials (measured against Ag-AgCl) correlate with the ratio of the concentrations of substrate and product. It is shown, how absolute measurements can be performed. The electrodes are calibrated in Tris-HCl-buffer solutions pH 8. 1.3. To study the fine structure of sediments matrix bound colour reactions are used. The matrices are fixed to glass slides.Glucose is bound glycosidically to an epoxy resin. After exposition the remaining glucose is measured by a colour reaction. Dehydrogenases are detected by 2, 3, 5 triphenyltetrazoliumchlorid which is fixed to a matrix by spraying with a teflon aerosol. The yellow formazan colour is measured. Hydrogen sulfide is detected by lead acetate which is enclosed in the cells of a dried emulsion. The walls are permeable for gas (H2S), but not for the insoluble reaction product. All reactions are calibrated in Tris-HCl-buffer solutions pH 8.

Description: Untersuchungen über die Zusammensetzung aquatischer Bakterienpopulationen hinsichtlich ihrer Fähigkeit zur Verwertung verschiedener Kohlenstoffquellen sind bisher wenig durchgeführt worden, da es an adäquaten Methoden mangelt. Es wird eine kombinierte Methode mit 14C-markierten Substraten, Nährkartonscheiben, Membranfiltern und Autoradiographie beschrieben, mit der verschiedene physiologische Gruppen erfaßt werden können. Kolonien mit besonderen Eigenschaften (z. B. Phenol oder DDT-Abbauer) können leicht identifiziert und isoliert werden. Die bisherigen Ergebnisse zeigen, daß einige der getesteten Substrate (Glucose, Asparaginsäure, Acetat) stets von fast allen Saprophyten aufgenommen werden können, während die Aufnahme anderer (z. B. Xylose, Lactose, Harnsäure, Phenol, Riboflavin, Fett) sowohl jahreszeitlich bedingte als auch von der Verschmutzung und Küstenentfernung abhängige Fluktuationen aufweist. Von dem größeren Spektrum der Nährstoffverwertung durch Bakterien in Küstengewässern kann eine schnelle Adaptation an Abwasserinhaltsstoffe erwartet werden, während in küstenferneren Gebieten entsprechende Populationen nur sehr schwach vertreten sind. Investigations on the composition of aquatic bacterial populations in respect of their nutritional requirements have been rarely made because of the lack of adequate methods. A combined method using 14C-marked substrates, nutrient pads, membrane filters and autoradiography is described, which enables one to differentiate the physiological groups of bacteria. Colonies with special properties (e.g. degradation of phenol or DDT) can easily be identified and isolated. The preliminary results show that some of the test substrates (glucose, aspartic acid, acetate) can always be taken up by most of the bacteria. Others (e.g. xylose, lactose, uric acid, phenol, riboflavin, fat) show seasonal and environmental fluctuations. The wide spectrum of nutritional requirements of bacterial populations in coastal reagions may lead to a quick adaption to sewage compounds, while in offshore regions the corresponding populations are rather small.

Description: Die Schlei von Schleimünde bis Schleswig betrachtet, stellt in mancher Hinsicht ein Modell der Ostsee dar. Es werden Angaben zur Verbreitung der gefundenen Arten auf sekundärem Hartboden an den acht Stationen gemacht. Ein ökologischer Vergleich der Fauna mit der aus anderen Brackwassergebieten, dem Elbe-Ästuar, Dänischen Brackgewässern, dem Nord-Ostsee-Kanal, der Martwa Wisla (Danziger Bucht) und der finnischen Küste wird ebenso durchgeführt, wie ein Vergleich mit den Ergebnissen von Remane und Jaeckel, die eine ähnliche Arbeit 1937 im gleichen Gebiet durchführten. The Schlei Fjord from Schleimünde to Schleswig seen as closed area is like a model of the Baltic Sea. Dates on the distribution of the occuring species are reported. An ecological comparison between the Schlei Fjord and different other brackish water areas is performed as well as a reference to dates worked out about the same area by Remane and Jaeckel in 1937.

Description: Die vorliegende Arbeit sollte klären, welchen Einfluß die Seewasser-Reinigungsanlage im Aquarium des Instituts für Meereskunde in Kiel auf den Bakteriengehalt des Aquariumwassers hat. Es wurde festgestellt, daß wesentliche Unterschiede in der Belastung des Wassers im Vergleich zum Fördewasser bestehen, insbesondere weist das Wasser des Aquariums eine sehr hohe Konzentration an Phosphat und Nitrat auf. Es wurden die auf Grund ihres Salzanspruches auf verschiedenen Nährböden wachsenden saprophytischen Bakterien gezählt. Es zeigte sich, daB die Saprophytenzahlen starken Schwankungen unterlagen; die Gründe hierfür könnten weitgehend analysiert werden. Die Saprophytenzahlen nehmen beim Durchlauf des Wassers durch die Reinigungsanlage ab, wenn Ozon eingeleitet wird. Es handelt sich aber in diesem Falle nicht um eine unmittelbare Wirkung des Ozons durch dessen oxydierende Wirkung, sondern um eine mittelbare, indem die Schaumbildung gefördert wird. Mit dem Schaum werden neben anderen partikulären Verunreinigungen auch Bakterien dem Wasserkreislauf entzogen. Zur Keimtötung reichen die verfügbaren Ozonmengen nicht aus. Die Anlage erfüllt zwar ihre Aufgabe, indem sie das Wasser von löslichen Proteinen und partikulären Verunreinigungen befreit und das giftige Nitrit zu unschädlichem Nitrat oxydiert, jedoch ist die Nutzung der Anlage nicht optimal. Zusätzliche Versuche mit Ozon zeigten, daß zur Keimtötung im belasteten Aquarienwasser mit den gegebenen Ozonmengen lange Einwirkungszeiten erforderlich sind. Es konnte auch gezeigt werden, daß der Wirkungsgrad des Ozons von der Belastung des Wassers mit oxydierbaren organischen und anorganischen Stoffen abhängig ist.

Description: Volcanic ash layers, which represent the products of volcanic activity within the ocean basins, are common in sedimentary cores taken near Cobb Seamount and on the actively spreading Gorda and Juan de Fuca Ridges. Petrographic and chemical analyses of the glass shards from these deposits have revealed that they are unaltered and are as chemically representative of local volcanic events as are the glassy margins of fresh pillow basalts recovered from the same areas. The presence of unhydrated glass shards in samples as old as 3.8 my is in direct conflict with published hydration rates of both terrestrial and submarine volcanic glasses. A study of a sequence of ash layers from Cobb Seamount, which spans in time much of the Seamount's history, indicates that the volcanic products from Cobb Seamount have had alkaline affinities and that its eruptions have been becoming progressively enriched in Al2O3. Recent experimental petrological evidence and the data on the chemical compositions of Cobb Seamount and the adjacent Juan de Fuca Ridge magmas are in agreement with the hypothesis that magmas are being generated at progressively greater depths beneath Cobb Seamount as it migrates away from the Juan de Fuca Ridge.

Description: Four palaeogeographical reconstructions are presented for the southern Cape covering the period Late Permian to Late Cretaceous. This time spans the commencement to an advanced stage of breakup of Gondwanaland, during which the area moved from a mid-continental, high latitude, to an ocean-dominated, middle latitude position. These movements can be traced in facies changes and erosional cycles associated with the rift between West Gondwana and Antarctica (proto southwest Indian Ocean) and the later rift between South America and Africa (proto southeast Atlantic Ocean).

Description: The Agulhas Bank, which forms the continental margin on the southern tip of Africa, consists of a thick Meso-Cainozoic sedimentary sequence (up to 6.2 km) resting on and behind pre-Mesozoic continental acoustic basement. The stratigraphy of this sequence is outlined and its history and facies variations mentioned where they are known. Refraction seismic velocity and bottom sample data indicate a basic three-fold subdivision of the Mesozoic sequence, which can be correlated with the onshore succession in the Algoa Basin. It is separated by a major hiatus from the Cainozoic sediments, which consist of a Palaeogene and Neogene sequence subdivided by another well-defined level of erosion. Various formations within the Cainozoic are defined and named. An outline of the bathymetry of the eastern Agulhas Bank is also given.

Description: Two thousand and twenty well-characterized coral specimens from 17 localities have been analyzed for Sr. Seventy-three genera and subgenera, mostly hermatypic scleractinians, are represented. For some genera, specimens living in surface reef environments are compared with those from 18.3 m depths on the same reefs. Growth rates for some species have also been measured at these depths at one of the sampling sites. Skeletal strontium for a given genus decreases with increasing water temperature, a relationship which previously eluded detection. Aragonite deposited by corals living on the reef at a depth of 18.3 m contains more strontium than the skeletal aragonite of the same coral genera from shallow-water, surface environments. Quantitative treatment of the data for Acropora, one of the most abundant and widely distributed of the reef-building corals, suggests that the observed strontium variations may reflect variations in the rate of skeletal calcification, rather than direct dependence upon temperature or water depth. There is evidence for ‘species effects’, apparently unrelated to growth rate differences, in that certain coral genera are consistently enriched or depleted in skeletal strontium content relative to other genera living in the same reef environments under identical ambient conditions. Temperature, salinity, water depth, seawater composition, and/or other such parameters may in part determine the levels of trace element concentration in carbonates deposited by corals and other marine invertebrates, but it would appear that these variables more directly affect physiological processes which in turn control skeletal chemistry.

Description: Surface area measurements as well as organic carbon, nitrogen and phosphorus analyses on various grain size fractions of carbonate mud samples confirm that in natural environments of carbonate deposition, surface sorption processes take place which are similar to those described earlier for dissolved organics and artificially suspended calcite particles in both seawater and synthetic solutions. The specific surface area of the sediment increases from 1.8m2/g for the coarse-grained fraction to 12.5 m2/g for the fine material; likewise organic carbon, nitrogen and phosphorus increase with increasing surface area so that there are 1.20 mg C, 0.175 mg N and 0.06–0.20 mg P associated with every square meter of carbonate surface irrespective of the mineralogy of the sediment particles. It appears that the organic matter in these sediments is similar in composition, structure and quantity to the organic layers produced in sorption experiments. With their apparently defined structure and ubiquitous nature, these layers could determine the mineralogy and orientation of submarine carbonate cement or could even be a prerequisite to calcification in general.

Description: Aus einer wäßrigen Lösung des Crustaceenäautungshormons Ecdysteron wurden Bakterien in Reinkultur isoliert, die das Hormon abzubauen vermögen. Die mögliche Bedeutung der bakteriellen Inaktivierung des Ecdysterons wird diskutiert. A bacterium which is able to degrade the crustacean malting hormone ecdysterone was isolated from an aqueous solution of the hormone. The possible significance of this inactivation by bacteria is discussed.

Description: Tauchuntersuchungen ermöglichten erste quantitative Angaben über das Vorkommen der Bohrmuschelarten Barnea candida und Zirfaea crispata in der Kieler Bucht. Die Muscheln bewohnen in hoher Siedlungsdichte Geschiebemergelflecken zwischen 2 und 13 m Wassertiefe. Ihre Bedeutung für die Auflockerung des Substrats, das dadurch auch von anderen Benthosformen besiedelt werden kann, ist beträchtlich. Diving investigations have provided first quantitative data on the occurence of boring clams (Barnea candida and Zirfaea crispata) in Kiel Bay. In a zone between 2 and 13 metres of water depth, the clams live in patches of till in large numbers. They have a considerable importance for eroding the substratum, which thus can be inhabited by other benthic species as well.

Description: Fluctuations of horizontal and vertical wind speed components and of air temperature have been measured on a mast in the Baltic Sea. Preliminary results of computed stress and sensible heat flux and their parametrisation with wind speed and air-sea temperature difference are given. Compared with the results of other authors, the present data show the following features: 1. The drag coefficient increases strongly with increasing wind speed. 2. The heat transfer coefficient seems to be smaller under stable stratification than under neutral or unstable conditions.

Description: The thermocline model suggested by ERTEL (1953) is used to describe thin surface layers that had been observed in the Western Baltic. The layers have typical vertical scales of a few decimeters, and their temperature exceeds the temperature of the underlying water by a few tenth °C. Advection is taken into account by means of a source function (including heat sources and sinks). The special case of the mixing coefficient of heat sinks and sources being equal to the coefficient of turbulent heat conduction can be used here if the coefficients are close to the molecular coefficient of heat conduction (approx. 10-3cm 2s-1). The results show that this special case of the model is applicable here. Using the above assumption the vertical temperature distribution during the heating period can be well approximated by using coefficients (10 to 40 10-3cm2s-l) which are sufficiently close to the molecular value.

Description: Es wird eine Methode zur Bestimmung des Kaloriengehaltes von partikularer Substanz aus Schöpfer- und Sinkstoffproben beschrieben. Die Proben werden auf Glasfaserfilter (Whatman GF/C, 2,25 cm Durchmesser) oder Membranfilter (Sartorius, Typ SM 1130, 2,5 cm Durchmesser) filtriert. Die Glasfaserfilter mit dem Filterrückstand werden nach Zugabe von Benzoesäure, die in Äthylalkohol gelöst ist, getrocknet und in einem Phillipson-Mikrokalorimeter verbrannt. Bei der Verbrennung der Membranfilter entfällt die Zugabe von Benzoesäure, da die Filter aus explosivem Cellulosenitrat bestehen. Sie können direkt nach der Trocknung verbrannt werden. Der methodische Fehler liegt bei der Verwendung von Glasfaserfiltern bei 27,1% und bei der Verwendung von Membranfiltern bei 9,6%. Als optimal erwies sich die Verwendung von Membranfiltern der PorengroBe 0,8 µ und die zweimalige Spülung des angereicherten Sestons auf dem Filter mit 2 bis 5 ml destilliertem Wasser. Die Glasfaser- und die Membranfilter weisen keinen signifikanten Unterschied in Bezug auf den Kaloriengehalt des abfiltrierten Sestons auf. In Bezug auf den Sestongehalt (als Trockengewicht) zeigt der Glasfaserfilter eine signifikant höhere Retention gegenüber dem Membranfilter (p1 〈 2% und p2 〈 0,1%). Es ergab sich ein signifikanter Unterschied (p 〈 0,2% in Bezug auf den Seston- und p 〈 0,1 % in Bezug auf den Kaloriengehalt) in der Retention der Filter bezogen auf 1 l Wasser bei der Filtration unterschiedlicher Wassermengen (1 l und 2 l). Aus diesem Grunde sollte immer die gleiche Menge Wasser zur Filtration verwendet werden. Der kalorische Aspekt der Phytoplanktonblüte im Frühjahr 1972 vor Boknis Eck wird dargestellt und diskutiert. Der Kaloriengehalt einer Phytoplanktonpopulation kann als Index für deren physiologischen Zustand angesehen werden.

Description: Different food species cause modifications in the growth forms of bryozoan species. Under cultivation conditions a "stolonization of zooids" is possible in Bowerbankia spp. In some species, e.g. Conopeum seurati and Alcyonidium spp., the numbers of tentacles are influenced by external and physiological conditions. Observations on the brackish water Membraniporid Conopeum seurati are summarized, which revealed that maturity and growth of the erect form are effected by a complex of interdependent factors (colony size, food, temperature, salinity). It is stressed that greater attentions should br paid to the ecologial conditions by taxononoists and systernatists. Numerical inquiries and statistical comparisons which ignore the influences of external factors on the growht forms are questionable. Cultivated Bryozoa may develop forms which under natural conditions will not normally be realized, but which may be of systematic importance. A new cultivation apparatus for long term rearing of sessile plankton feeders has been developed. The experimental vessel of the apparatus has a U-bottom of perspex to sustain a vertical water rotation. The water movement is produced by water in a container vessel, raised above the level in the experimental vessel by an improved type of a bubble-pump. The experimental animals can be observed with a stereo-microscope or with a photo-apparatus without removal from the experimental vessel.

Description: This work is based on 63 samples obtained by Beyer's 50 cm epibenthic closing net and 43 vertical hauls with a 70 cm Hensen-net from December 1969, and March, June and November 1970. The depth in the sampling locality, Vejsnäs Rinne, varied between 28 and 32 meters. Only abundant and particularly interesting species and animal groups have been treated here. Seasonal variations were studied in the cumacean Diastylis rathkei, some mysids, the euphausid Thysanoessa raschii, the decapod Crangon crangon, the chaetognath Sagitta elegans and in some fishes. During winter there are, relatively, a higher number of species (including some rare ones), as well as of individuals. This may partly be ascribed to a stronger inflow of water from the Kattegat in winter, and partly to seasonal horizontal migrations in the animals. It is furthermore apparent that by the present sampling method a larger fraction of the more vagile near-bottom fauna is collected than by more conventional sampling techniques. The diurnal variations in the hyperbenthos were studied in benthic as well as some pelagic groups of animals. Based on the results, it is possible to recognise at least three main patterns of vertical migrations in the hyperbenthos: A. The relatively few pelagic animals found stay just above the bottom during the day. They leavethe region sampled by the epibenthic closing net (i.e. from the bottom to about 80 cm above it) about sunset and stay away until the next morning when they reappear at this level. B. Some of the benthic animals at certain seasons or developmental stages are sparsely represented in the epibenthic closing net samples during day. The catches are increased at dusk, but decrease again later in the evening. In the morning the animals appear once more in the hyperbenthos, only to disappear again after sunrise. The reduced number collected around midnight is either due to midnight sinking, i.e. the animals burrow in the sediment and thus avoid the epibenthic net, or the animals ascend above the level sampled by the net. This last pattern is particularly found in juveniles and in gravid females. C. The majority of the migrating benthic species seem to come sufficiently far off the bottom to be caught in higher numbers in the epibenthic closing net during the dark hours. They are often considerably less numerous throughout the day. The value to an animal of performing diurnal vertical migration has been briefly discussed. It seems possible that some of the more important demersal fishes in the area are able to exploit the migrating animals as food, particularly at dawn and dusk.

Description: Ein Vergleich des Typs und eigenen Materials von Amphiascus graciloides trisetatus KLIE beweist, daß diese Subspezies nicht aufrechterhalten werden kann. Die Exemplare lassen sich vielmehr Amphiascus minutus (CLAUS) sp. I; LANG, 1965 zuordnen. A comparison between the type of Amphiascus graciloides trisetatus KLIE with own material of the Kiel Bay shows the invalidity of that subspecies. The specimens have to be referred to Amphiascus minutus (CLAUS) sp. I; LANG, 1965.

Description: Records of temperature fluctuations in a thermocline show an energy peak close to the local Brunt-Väisälä frequency. This supports recent observations that short internal waves are common phenomena within the thermocline. The high rate of energy of these waves permits the conclusion that they may break and form patches of turbulence. It is assumed that these short internal waves and turbulence patches contribute to the acoustic backscattering observed from these layers.

Description: Von den 50 bisher aus der Kieler Bucht nachgewiesenen Hydroidenarten werden einige ökologische Aspekte dargestellt. Die Besonderheiten des Salzgehaltes, der Temperatur und des Substratangebotes in der westlichen Ostsee werden in ihrer Wirkung auf die Hydroiden beschrieben. Der bestandsmindernde, indirekte Einfluß von Licht auf Flachwasser-Hydroidengemeinschaften wird dargestellt. Ecological aspects concerning the 50 species of hydroids known from the Kiel Bay are discussed. The effects of salinity, temperature and substrate availability on these species in the Western part of the Baltic are described. It is pointed that light influences the density of hydroid populations in shallow waters by favouring the growth of algae competing with hydroids for space.

Description: Auf 2 Fahrten in die Ostsee (September 1971 und April 1972) sind mit Hilfe der Invers-Voltammetrie 97 Metallanalysen direkt an Bord durchgeführt worden. Untersucht wurden auf 12 verschiedenen Stationen die Metalle Zink, Cadmium, Blei und Kupfer. Die mittleren Konzentrationen lagen 1971 und 1972 für Zn bei 8,9 bzw. 7,5 μg/dm3, für Cd bei 0,17 bzw. 0,22 μg/dm3, für Pb 1972 bei 1,1 und für Cu im Jahre 1971 bei 3,1 µg/dm3. Die Verteilung und Streuung der Einzelwerte wird diskutiert. Aufbau, Arbeitsweise und Meßgenauigkeit der Versuchsapparatur werden beschrieben. Shipboard measurements of trace metals have been carried out on 2 cruises (September 1971 und April 1972) by anodic stripping voltammetry. 97 samples from 12 different stations were analyzed for zinc, cadmium, lead and copper. The mean values in 1971 and 1972 are 8,9 and 7,5 µg/dm3 for Zn respectively, while for Cd they are 0,17 and 0,22 μg/dm3, for Pb 1,1 μg/dm3 has been found in 1972 and for Cu 3,1 μg/dm3 in 1971. The distribution and variations of the individual values are discussed. The construction, method and precision of the apparatus is described.

Description: Auf drei Stationen (Sand - 7,5 bis 12 m Tiefe) wurde in der Kieler Bucht die Meiofauna quantitativ für das Jahr 1969 erfaßt. Teilweise wurden auch noch Proben von 1968 und 1970/71 herangezogen. Die Probenentnahme erfolgte mit dem Reineck-Kastengreifer (150 kg-Gerät). Die untersuchte Menge pro Station und Monat betrug 10,6 cm2; dies entspricht 21,2 cm3 (Einstichtiefe = 2 cm). Es wurde der EinfluB von Temperatur, Salzgehalt und Korngröße des Substrates auf die Meiofauna im Jahresablauf untersucht. Zwei verschiedene Korngrößen wurden miteinander verglichen. Das Substrat war weitgehend "rein" und wurde in 9 Fraktionen zerlegt. Die Proben wurden im Labor fixiert (4% Formol) und die Meiofauna aufgeschwemmt und abpipettiert. Beide Substratqualitäten zeigten eindeutige Unterschiede in der Besiedlung durch die Meiofauna. Dies gilt für das Mengenverhältnis der einzelnen Meiofauna-Gruppen zueinander und besonders das Artenspektrum der Harpacticoiden. Die Besiedlungsdichte betrug auf grobem Sand 385300 Tiere/m2; auf mittlerem Feinsand 542180 bis 580920 Tiere/m2. Für Harpacticoiden und Nematoden wurden zwei Besiedlungs-Maxima ermittelt; ein kleineres im Winter (Dezember/Januar) und ein größeres im Sommer (Juli/August). The meiofauna was quantitatively recorded at three stations (sand bottoms, depth 7,5 to 12 m) in the Kiel Bay for the year 1969 as well as from some additional samples taken in 1968 and 1970/71. Samples were taken with a Reineck-grab (150 kg.). 10,6 cm2 X 2 cm were examined per station and month. This is equivalent to 21,2 cm3. The effect of temperature, salinity and grain size of the substrate on the meiofauna in the course of a year was studied. Two different grain sizes were compared with each other. The substrate was largely "pure" and was divided in 9 fractions. Samples were fixed in the laboratory with 4% formol and the meiofauna was washed out and collected. Both substrate types showed a clear difference with regard to population. This applies to the quantitative relationship between the various groups of the meiofauna to each other and to the species composition of the Harpacticoidea. 542.180 to 580.920 individuals/m2 were calculated for medium fine sand and 385.300 for the coarser sand. Two maxima for Nematodes and Harpaticoides were determined, a smaller one in winter (December/Januar) and a larger one in summer (July/August).

Description: Messungen der Energiedissipation stehender Wellen mit laminarer Bewegung wurden im Tank durchgeführt und mit theoretischen Werten verglichen, die sich aus Ableitungen der linearisierten Bewegungsgleichung von NAVIER-STOKES ergeben. Dabei wurde die Dämpfung der Oberflächenauslenkung sowie die von den stehenden Wellen auf den Tankboden ausgeübte Schubspannung gemessen. Es ergab sich eine etwas größere Energiedämpfung als die theoretisch vorhergesagte. Die Schubspannung stimmte innerhalb der Fehlerbreite mit der Theorie überein.

Description: A great number of observations, mainly on temperature and current fluctuations in the Arkona Basin, have been made during the years 1962-1968 (figs. 2 and 4). Corresponding to the wind conditions over the Baltic Sea (mean value about zero, fluctuations of about 5 m sec-1), currents and stratification are extremely variable. The mean currents in fig. 7 are towards NE for the entire eastern part of the Arkona Basin, but the actual flow can have any direction (fig. 32). The current fluctuations are non-Gaussian (fig. 10). The mean stratification in the Arkona Basin underlies also great variations. Temperature fluctuations of 8°C and salinity fluctuations of 3 ‰ occur within 2 days (fig. 5). In the mean thermocline level we find also in the central part of the Arkona Basin a current towards NE (fig. 9). The current spectra of the Belt Sea and the Arkona Basin are principally of the same shape, but inertial waves do not occur in the Belt Sea (fig. 13). The mode decomposition reveals the strongest baroclinity in the period range from approximately 10h - 40h; at the inertial frequency the major baroclinic mode contains 10 times the energy of the barotropic one (fig. 28). The spectrum of the barotropic mode corresponds to the spectrum of the windstress whereas the spectra of the internal modes correspond to divergence and curl of the stress field (fig. 28). The strongest signal are the inertial currents. In general their wave length seems to be short; they consist of at least 4 internal modes and the barotropic one (fig. 37). The Reynolds stress clue to inertial waves leads to negative viscosity (fig. 40). The seiches currents are very weak compared to the inertial currents. The oscillations in the Arkona Basin seem to be short-crested and strongly influenced by Bornholm and the Rönne Bank. Towed thermistor cable records lead to the conclusion that several features of the temperature structure are of quasi-permanent character.

Description: In den Jahren 1970/71 wurden an Terminstationen in etwa vier Wochen Abstand mit zwei Geräten Planktonproben entnommen: das Bongo-Gerät filterte die gesamte Wassersäule gleichzeitig mit zwei Netzen von 300 µ und 500 µ Gaze. Das Neuston-Gerat befischte nur die obere 35 cm tiefe Wasserschicht mit zwei Netzen, beide mit 500 µ Gaze. Aus den Fängen des 300 µ Netzes wurde das Zooplankton volumenmäßig bestimmt und die Resultate der Fangreisen auf Verbreitungskarten in ml Verdrängungsvolumen/100m3 gefilterten Wassers dargestellt. Das typische Bild der Verbreitung ist die wolkenartige Verteilung des Planktons. Es wurde die Vermutung geäußert, daß es in der Kieler Bucht kein ungestörtes Planktonwachstum über längere Zeit hin wegen der kurzfristigen hydrographischen Veränderungen geben kann. Eine Umrechnung vom Verdrängungsvolumen in Trockengewicht wurde vorgenommen. Der Anteil an Trockensubstanz während der Untersuchungszeit betrug im Mittel 14,2%, es handelte sich überwiegend um Copepodenplankton. In 1970/71 plankton samples were taken every four weeks on a 6 sm station grid in Kiel Bay. A Bongo net supplied with 300 µ and 500 µ gauze was used for sampling the water column (oblique hauls). Simultaneously a neuston net (500 µ gauze) collected surface plankton. The samples of the 300 µ Bongo net were used to determin displacement volumes of zooplankton. The distribution of zooplankton vol./100 m3 water of each cruise is given in distributionmaps. Smal patches seems to be the charakteristical distribution of zooplankton in Kiel Bay. It is assumed that the short term hydrographical changes do not allow the undistrubed development of plankton populations. The displacement volume has been converted into dry weight. The average amount of dry substances during the sampling period was 14,2%. The plankton consisted mainly of Copepods.

Description: Der Polyp einer neuen Art der Gattung Dipurena wird ausführlich beschrieben. Für das zugehörige Medusenstadium wird eine vorläufige Beschreibung gegeben. D. spongicola ist die erste bekanntgewordene Hydrozoenart, die ihr gesamtes Polypenstadium im Innern eines Schwammes (Halichondria panicea PALLAS) vollendet und die erste Dipurena-Art, die im Kattegat und der nördlichen Kieler Bucht nachgewiesen wird. Die wesentlichsten Unterscheidungsmerkmale zu drei ähnlichen Arten werden diskutiert. Es werden erste Angaben zur Ökologie und Biologie des beschriebenen Hydroiden gemacht. A detailed description of the hydroid and a preliminary one of the medusa stage of a new Dipurena-species is given. Dijmrena spongicola is the first Hydrozoan known to spend its whole hydroid stage inside sponges (Halichondria panicea PALLAS). lt is the first species of the genus Dipurena recorded from the Kattegat and the northern Kiel Bay. The most important characters distinguishing it from three other species are discussed. Preliminary observations concerning the ecology and biology of the new species are reported.

Description: Gelegentlich einer Bearbeitung des Cyprina islandica-Bestands der Kieler Bucht im Jahr 1968 wurde auch der Befall dieser Muschel mit dem kommensalischen Nemertinen Malacobdella grossa ermittelt. Von insgesamt 534 untersuchten Islandmuscheln waren ca. 27% befallen; die Befallsrate ging in den letzten 60 Jahren um mehr als die Hälfte zurück. Größere Muscheln enthielten den Nemertinen wesentlich häufiger als kleine. Regional bestehen Unterschiede, die aber nicht mit der Häufigkeit von Cyprina korrelierbar sind. Juvenile und adulte Nemertinen traten das ganze Jahr hindurch auf; eine Periode intensiver Fortpflanzung war nicht zu erkennen. Eine Schädigung befallener Islandmuscheln durch den Kommensalen ist nicht nachzuweisen. On the occasion of a study of the soft clam (Cyprina islandica L.) stock in Kiel Bay during 1968, the infestation of this bivalve with the entocommensal rhynchocoelan Malacobdella grossa was noted. Of a total of 534 soft clams investigated, about 27% were infested; this is less than half the rate found 60 years ago. Larger bivalves contained the nemertean much more frequently than smaller specimens. There are regional differences, which can, however, not be correlated with the abundance of Cyprina. Juvenile and adult nemerteans occured throughout the year; a period of intensive breeding was not noticed. A negative effect of the commensal on its host cannot be proved.

Description: An bakterienfreien Kulturen von Amphidinium höfleri in vollsynthetischem Nährmedium konnte mit dem Coulter-Counter gezeigt werden, daß gelöste Aminosäuren in Konzentrationen von 50 mg/l eine Erhöhung des Zellvolumens der Population um 6,1% bewirken. Eine Beeinflussung der Generationszeit konnte nicht festgestellt werden. Wurden die Aminosäuren in Konzentrationen von 200 µg/l, also in Konzentrationen, wie sie im Pelagial des Meeres vorkommen, geboten, so konnte keine Förderung des Wachstums nachgewiesen werden. With axenic cultures of Amphidinium höfleri it was shown by using the Coulter-Counter, that dissolved amino-acids in concentrations of 50 mg/l will increase the cellvolume by 6.1%. There was no effect on the generation time. If the aminoacids were added in concentrations of 200 µg/l - the concentration of natural sea water - then there was no effect.

Description: Untersucht wurden die Komponenten Bremsfallschirm, Kunststoffseil, Sollbruchstelle und federgesteuerter Auslöser. Der Bremsfallschirm hat die Aufgabe, die Sinkgeschwindigkeit des Ankersteins während der Freifallphase zu vermindern. Das Kunststoffseil stellt einen vollwertigen Ersatz für Stahlseile in großen Wassertiefen dar, die einzelnen Komponenten der Verankerung miteinander zu verbinden. Sollbruchstelle und federgesteuerter Auslöser sind Teile des Sicherheitssystems zur Wiedergewinnung der Verankerung. Der Test des Bremsfallschirms zeigte die obere Grenze der Belastbarkeit auf, die mit über 2200 kp den Forderungen genügt. Öffnungsverhalten und Richtungsstabilität ließen nichts zu wünschen übrig. Die geprüften Kunststoffseile mit Nylon und Polypropylen als Ausgangsmaterial ließen das Problem der Seilmachart deutlich werden. Nylonseile mit monofilem Charakter sind geflochtenen Polypropylenseilen überlegen. Geringe Dehnung und mäßiges Kriechen unter Last zeichnen das geprüfte Nylonseil aus. Für die Sollbruchstelle liegt aufgrund der Ergebnisse eine Standardform mit Standarddurchmessern vor, so daß auf zeitraubende Prüfungen vor Beginn einer neuen Expedition bei dieser wichtigen Komponente verzichtet werden kann. Die Ergebnisse der Tests des Federauslösers weisen auf die Schwierigkeit hin, Korrosionsglieder als zeitbestimmende Elemente einzusetzen. Das erstellte Kennfeld erlaubt nunmehr, nach Abschätzung der Einflußgrößen die obere und untere Grenze des Auslöseintervalls zu ermitteln. In einer Sicherheitsbetrachtung wird hervorgehoben, daß die Federkraft in jedem Fall ausreicht, den Auslöser zu betätigen. Die Belastung, die aufgrund von Festigkeitsbetrachtungen für zulässig angenommen wird, stimmt gut mit der als Sicherheitsgrenze definierten Kraft von ca. 2000 kp überein.

Description: In der vorliegenden Untersuchung wird eine erste Bestandsaufnahme der quantitativen Hefeverteilung in der westlichen Ostsee gegeben. Zur Begründung der gefundenen zeitlichen und räumlichen Hefeverteilung werden verschiedene biotische und abiotische Faktoren untersucht. Es ergab sich eine starke Abhängigkeit von der jeweils vorherrschenden hydrographischen Situation, der Temperatur und dem Nährstoffgehalt des Ostseewassers. Die Frühjahrs- und Herbstmaxima der Hefeentwicklung traten in der Kieler Förde vor den vergleichsweise ermittelten Maxima der Bakterienzahlen auf. Mit zunehmender Küstenentfernung nimmt die „Biomasse" der Hefen stärker ab als die der Bakterien, im Durchschnitt wird eine Relation von 1 : 124 erreicht. In steril filtriertem Ostseewasser entstand und überlebte eine größere Zellzahl bei niedrigen Temperaturen (4°C, 12°C) als bei höheren Temperaturen (20°C, 25°C) (Rhodotorula-Stamm). Zur ersten Orientierung wurde die Generationszeit des Rhodotorula-Stammes H 25 in Ostseewasser durch eine kontinuierliche Kultur annäherungsweise ermittelt. Sie betrug 178 Stunden (25°C) bei einer Zelldichte von 5020 Zellen/ml und 263 Stunden (12°C) bei einer Zelldichte von 23800 Zellen/ml.