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Changes in marine net primary productivity (PP) and export of particulate organic carbon (EP) are projected over the 21st century with four global coupled carbon cycle-climate models. These include representations of marine ecosystems and the carbon cycle of different structure and complexity. All four models show a decrease in global mean PP and EP between 2 and 20% by 2100 relative to preindustrial conditions, for the SRES A2 emission scenario. Two different regimes for productivity changes are consistently identified in all models. The first chain of mechanisms is dominant in the low- and mid-latitude ocean and in the North Atlantic: reduced input of macro-nutrients into the euphotic zone related to enhanced stratification, reduced mixed layer depth, and slowed circulation causes a decrease in macro-nutrient concentrations and in PP and EP. The second regime is projected for parts of the Southern Ocean: an alleviation of light and/or temperature limitation leads to an increase in PP and EP as productivity is fueled by a sustained nutrient input. A region of disagreement among the models is the Arctic, where three models project an increase in PP while one model projects a decrease. Projected changes in seasonal and interannual variability are modest in most regions. Regional model skill metrics are proposed to generate multi-model mean fields that show an improved skill in representing observation-based estimates compared to a simple multi-model average. Model results are compared to recent productivity projections with three different algorithms, usually applied to infer net primary production from satellite observations.

Governing marine environments is a highly complex and challenging enterprise. This applies particularly to the heavily exploited Baltic Sea for which despite extensive governance arrangements and a substantial scientific knowledge base, it is unlikely that the policy objective of ‘good environmental status’ is reached. Based on a review of governance arrangements linked to five large-scale environmental issues (eutrophication, overfishing, invasive alien species, chemical pollution and oil spills from shipping), this chapter aims to identify pathways and concrete ideas for institutional reform that may improve goal fulfilment. The results show that governance challenges differ substantially between environmental issues, implying a need for case-specific management reforms. For example, coping with extreme uncertainty is a key challenge in the chemical pollution case, whereas it seems more pertinent in the eutrophication case to address the complexity of nutrient pollution sources by adapting objectives and measures amongst sectoral policies to be in line with environmental ones. Furthermore, cross-case comparisons reveal a set of common vital functions (i.e. coordination, integration, interdisciplinarity, precaution, deliberation, communication and adaptability) that are needed in order to facilitate effective and efficient environmental governance in the long term. To promote these functions in Baltic Sea environmental governance, the chapter suggests pathways and institutional reforms aimed at improving multilevel and multisectoral integration, science-policy interactions and stakeholder participation. To further develop these ideas, it is proposed amongst other things that priority is given to setting up an international ‘Baltic Sea Policy Review Mechanism’, formed by cross-body and cross-stakeholder participation.

The flow of warm and saline water from the Atlantic Ocean, across the Greenland–Scotland Ridge, into the Nordic Seas – the Atlantic inflow – is split into three separate branches. The most intense of these branches is the inflow between Iceland and the Faroe Islands (Faroes), which is focused into the Faroe Current, north of the Faroes. The Atlantic inflow is an integral part of the North Atlantic thermohaline circulation (THC), which is projected to weaken during the 21st century and might conceivably reduce the oceanic heat and salt transports towards the Arctic. Since the mid-1990s, hydrographic properties and current velocities of the Faroe Current have been monitored along a section extending north from the Faroe shelf. From these in situ observations, time series of volume, heat, and salt transport have previously been reported, but the high variability of the transport has made it difficult to establish whether there are trends. Here, we present results from a new analysis of the Faroe Current where the in situ observations have been combined with satellite altimetry. For the period 1993 to 2013, we find the average volume transport of Atlantic water in the Faroe Current to be 3.8 ± 0.5 Sv (1 Sv = 106 m3 s−1) with a heat transport relative to 0 °C of 124 ± 15 TW (1 TW = 1012 W). Consistent with other results for the Northeast Atlantic component of the THC, we find no indication of weakening. The transports of the Faroe Current, on the contrary, increased. The overall increase over the 2 decades of observation was 9 ± 8 % for volume transport and 18 ± 9 % for heat transport (95 % confidence intervals). During the same period, the salt transport relative to the salinity of the deep Faroe Bank Channel overflow (34.93) more than doubled, potentially strengthening the feedback on thermohaline intensity. The increased heat and salt transports are partly caused by the increased volume transport and partly by increased temperatures and salinities of the Atlantic inflow, which have been claimed mainly to be caused by the weakened subpolar gyre.

The gCube social networking facilities manifest in a number of applications made available through a thin Web browser are conceptually close to the common facilities promoted by social networks - e.g., posting news, commenting on posted news - yet adapted to deal with large scale collaboration and cooperation on comprehensive scientific products, data sets, theories and tools. Social Profile allow users to enter their professional data and contact information. It also allows to import the profile data directly from LinkedIn via the OAuth 2.0 protocol.

The extending record of ocean colour derived information, an important asset for the study of marine ecosystems and biogeochemistry, presently relies on individual satellite missions launched by several space agencies with differences in sensor design, calibration strategies and algorithms. In this study we present an extensive comparative analysis of standard products obtained from operational global ocean colour sensors (SeaWiFS, MERIS, MODIS-Aqua, MODIS-Terra), on both global and regional scales. The analysis is based on monthly mean chlorophyll a (Chl-a) sea surface concentration between 2002 and 2009. Based on global statistics, the Chl-a records appear relatively consistent. The root mean square (RMS) difference Δ between (log-transformed) Chl-a from SeaWiFS and MODIS Aqua amounts to 0.137, with a bias of 0.074 (SeaWiFS Chl-a higher). The difference between these two products and MERIS Chl-a is approximately 0.15. Restricting the analysis to 2007 only, Δ between MODIS Aqua and Terra is 0.142. This global convergence is significantly modulated regionally. Statistics for biogeographic provinces representing a partition of the global ocean, show Δ values varying between 0.08 and 0.3. High latitude regions, as well as coastal and shelf provinces are generally the areas with the largest differences. Moreover, RMS differences and biases are modulated in time, with a coefficient of variation of Δ varying between 10% and 40%, with clear seasonal patterns in some provinces. The comparison of the province-averaged time series obtained from the various satellite products also shows a level of agreement that is geographically variable. Overall, the Chl-a SeaWiFS and MODIS Aqua series appear to have similar levels of variance and display high correlation coefficients, an agreement likely favoured by the common elements shared by the two missions. These results are degraded if the MERIS series is compared to either SeaWiFS or MODIS Aqua. An important outcome of the study is that the results of the inter-comparison analysis are variable with time and location, and therefore globally averaged statistics are not necessarily applicable on a seasonal or regional basis.

The pennate diatom Haslea ostrearia is the emblematic and most studied species of the genus Haslea. H. ostrearia is mainly benthic and epiphyte, forming biofilm on sediment and on macroalgae. The cells produce a blue water-soluble pigment: the marennine with allelopathic, antioxidant, antiviral, antibacterial properties observed in laboratory conditions. Marennine is responsible for the greening of oysters in refining ponds in the Marennes Oléron area (France), a phenomenon that has economical and patrimonial values. Recently, new species of blue Haslea producing marennine-like pigments were described (H. karadagensis, H. nusantara, H. provincialis). Last years, large benthic blooms of blue Haslea spp. have been observed in natural environments, e.g. in Calvi Bay, Corsica France. First the species of Haslea responsible for the bloom were identified using morphological and molecular approaches. Their abundances were determined and cartography of the recent blooms localisations was achieved. Then, within shallow photophilous rocky habitats affected by the bloom, the epiphytic communities of some representant macroalgal species (Padina sp. and Acetabularia sp.) were studied using taxonomic identification tools. This information will be used to define if the release of marennine-like pigments during blooms affects the structure of the benthic epiphytic and epiplithic microfauna and microflora. This work represents the first studies on the dynamic of the bloom of Haslea in natural environment in open water. The Genus Haslea, New marine resources for blue biotechnology and Aquaculture

Momarsat 2022 cruise report: summary of dives and operations, and position of moorings and observation infrastructures and sampling locations

Precipitation of calcium carbonate by phytoplankton in the photic oceanic layer is an important process regulating the carbon cycling and the exchange Of CO2 at the ocean-atmosphere interface. Previous experiments have demonstrated that, under nutrient-sufficient conditions, doubling the partial pressure Of CO2 (pCO(2)) in seawater-a likely scenario for the end of the century-can significantly decrease both the rate of calcification by coccolithophorids and the ratio of inorganic to organic carbon production. The present work investigates the effects of high pCO(2) on calcification by the coccolithophore Emiliania huxleyi (Strain TW1) grown under nitrogen-limiting conditions, a situation that can also prevail in the ocean. Nitrogen limitation was achieved in NO3-limited continuous cultures renewed at the rate of 0.5 d(-1) and exposed to a saturating light level. pCO(2) was increased from 400 to 700 ppm and controlled by bubbling CO2-rich or CO2-free air into the cultures. The pCO(2) shift has a rapid effect on cell physiology that occurs within 2 cell divisions subsequent to the perturbation. Net calcification rate (C) decreased by 25% and, in contrast to previous studies with N-replete cultures, gross community production (GCP) and dark community respiration (DCR) also decreased. These results suggest that increasing pCO(2) has no noticeable effect on the calcification/photosynthesis ratio (C/P) when cells of E. huxleyi are NO3-limited.

Macroalgae, and particularly their lignin-free polysaccharides, are increasingly used for their gelling and therapeutic properties and for the production of biofuels and renewable chemical compounds. To extract, hydrolyze and purify this biomass, algae hydrolyzing enzymes are needed. Our work aims to identify and characterize algal biomass hydrolyzing enzymes expressed by microorganisms living on the surface of algae, by functional metagenomics. Therefore, a microbial DNA extraction method was developed to isolate the gDNA from the microorganisms of the brown algae Ascophyllum nodosum and a metagenomic library was constructed in Escherichia coli. The library was screened for diverse enzymatic activities (esterases, xylanases, cellulases, α-amylases, arabinanases, caseinases and β-glucosidases) on agar plates with specific enzymes substrates. Several new microbial enzymes (esterases, β-glucosidases, α-amylases and cellulases) were identified revealing the wealth of our library. Furthermore, those enzymes had less than 50% sequence identity with known protein sequences; meaning that our approach allows to identify new microbial enzymes expressed by uncultured microorganisms. Plate tests for medium-throughput screening of specific enzymes hydrolyzing algal polysaccharides (agarases, carrageenases and alginate lyases) are currently being developed. Our approach will probably allow us to identify new families of those ill-known enzymes, with particular enzymatic activities.

Despite being an abundant group of significant ecological importance the phylogenetic relationships of the Octocorallia remain poorly understood and very much understudied. We used 1132 bp of two mitochondrial protein-coding genes, nad2 and mtMutS (previously referred to as msh1), to construct a phylogeny for 161 octocoral specimens from the Atlantic, including both Isididae and non-Isididae species. We found that four clades were supported using a concatenated alignment. Two of these (A and B) were in general agreement with the of Holaxonia–Alcyoniina and Anthomastus–Corallium clades identified by previous work. The third and fourth clades represent a split of the Calcaxonia–Pennatulacea clade resulting in a clade containing the Pennatulacea and a small number of Isididae specimens and a second clade containing the remaining Calcaxonia. When individual genes were considered nad2 largely agreed with previous work with MtMutS also producing a fourth clade corresponding to a split of Isididae species from the Calcaxonia–Pennatulacea clade. It is expected these difference are a consequence of the inclusion of Isisdae species that have undergone a gene inversion in the mtMutS gene causing their separation in the MtMutS only tree. The fourth clade in the concatenated tree is also suspected to be a result of this gene inversion, as there were very few Isidiae species included in previous work tree and thus this separation would not be clearly resolved. A~larger phylogeny including both Isididae and non Isididae species is required to further resolve these clades.