Scottish Association for Marine Science

About: Scottish Association for Marine Science is a facility organization based out in Oban, United Kingdom. It is known for research contribution in the topics: Sea ice & Benthic zone. The organization has 524 authors who have published 1765 publications receiving 70783 citations. The organization is also known as: SAMS & Scottish Marine Station for Scientific Research.

Deep-water macrofaunal diversity in the Faroe-Shetland region (NE Atlantic): a margin subject to an unusual thermal regime

Abstract: The Faroe-Shetland Channel, situated in the NE Atlantic, encompasses a number of different sediment types (habitats) as well as being subject to an unusual thermal regime. Our main objective was to assess variations in macrofaunal generic diversity and composition along two transects to gauge the relative influence of regional hydrography and local habitat heterogeneity. We found that generic richness and diversity on a West of Shetland (WoS) transect correlated most strongly with temperature range, whilst along a North of Shetland (NoS) transect, richness and diversity correlated negatively with sedimentary variables, notably total organic carbon. Macrofaunal composition at WoS is also strongly influenced by water temperature with specific genera (e.g. Galathowenia positively associated with the temperature eigenvectors), whereas at NoS it is a combination of temperature, silt + clay fraction and total organic carbon that has an impact on composition (e.g. Proclea and Pseudosphyrapus, showing a negative relationship with the temperature eigenvectors). Although the temperature regime exerts a strong control on regional ecology, local habitat heterogeneity remains a significant factor.

Marine Microbial Gene Abundance and Community Composition in Response to Ocean Acidification and Elevated Temperature in Two Contrasting Coastal Marine Sediments.

Abstract: Marine ecosystems are exposed to a range of human-induced climate stressors, in particular changing carbonate chemistry and elevated sea surface temperatures as a consequence of climate change. More research effort is needed to reduce uncertainties about the effects of global-scale warming and acidification for benthic microbial communities, which drive sedimentary biogeochemical cycles. In this research, mesocosm experiments were set up using muddy and sandy coastal sediments to investigate the independent and interactive effects of elevated carbon dioxide concentrations (750 ppm CO2) and elevated temperature (ambient +4°C) on the abundance of taxonomic and functional microbial genes. Specific quantitative PCR primers were used to target archaeal, bacterial, and cyanobacterial/chloroplast 16S rRNA in both sediment types. Nitrogen cycling genes archaeal and bacterial ammonia monooxygenase (amoA) and bacterial nitrite reductase (nirS) were specifically targeted to identify changes in microbial gene abundance and potential impacts on nitrogen cycling. In muddy sediment, microbial gene abundance, including amoA and nirS genes, increased under elevated temperature and reduced under elevated CO2 after 28 days, accompanied by shifts in community composition. In contrast, the combined stressor treatment showed a non-additive effect with lower microbial gene abundance throughout the experiment. The response of microbial communities in the sandy sediment was less pronounced, with the most noticeable response seen in the archaeal gene abundances in response to environmental stressors over time. 16S rRNA genes (amoA and nirS) were lower in abundance in the combined stressor treatments in sandy sediments. Our results indicated that marine benthic microorganisms, especially in muddy sediments, are susceptible to changes in ocean carbonate chemistry and seawater temperature, which ultimately may have an impact upon key benthic biogeochemical cycles.

Bacterial diversity of Gymnodinium catenatum and its relationship to dinoflagellate toxicity

Abstract: Gymnodinium catenatum Graham (Dinophyceae) is one of several marine dinoflagel- lates responsible for outbreaks of paralytic shellfish poisoning (PSP), a problem that is considered to be increasing globally. Bacteria associated with these dinoflagellates have been implicated as poten- tially involved with the production of PSP toxins, and this study sought to identify whether there was a link between the toxicity of G. catenatum laboratory cultures and the diversity of the associated bacterial community. Bacterial 16S rRNA gene clone libraries were constructed and sequenced to identify the bacterial diversity of 7 G. catenatum cultures of 2 contrasting toxicity levels. Phylogenetic membership and community structure were examined, including the use of UniFrac, FST and LIB- COMPARE. No statistically significant differences that distinguished between toxic and low-toxicity G. catenatum cultures were identified in the bacterial community membership or structure. Further- more, no coherent phylogenetic group of bacteria was observed to co-associate with culture toxicity. However, observed variation in bacterial diversity and community structure was based on the geo- graphic origin of the G. catenatum cultures. Overall, while it was not possible to identify an apparent link between bacterial diversity and the toxicity of G. catenatum cultures, we suggest, on the balance of this study and others, that bacterial influence on PSP toxin production may be indirect and medi- ated by the effects of the bacterial community on algal physiology.

Achieving good environmental status in the Black Sea: scale mismatches in environmental management

Abstract: European Commission (Seventh Framework Programme FP7/2007-2013 under grant agreement number 226675)

An approach for the identification of exemplar sites for scaling up targeted field observations of benthic biogeochemistry in heterogeneous environments

Abstract: Continental shelf sediments are globally important for biogeochemical activity. Quantification of shelf-scale stocks and fluxes of carbon and nutrients requires the extrapolation of observations made at limited points in space and time. The procedure for selecting exemplar sites to form the basis of this up-scaling is discussed in relation to a UK-funded research programme investigating biogeochemistry in shelf seas. A three-step selection process is proposed in which (1) a target area representative of UK shelf sediment heterogeneity is selected, (2) the target area is assessed for spatial heterogeneity in sediment and habitat type, bed and water column structure and hydrodynamic forcing, and (3) study sites are selected within this target area encompassing the range of spatial heterogeneity required to address key scientific questions regarding shelf scale biogeochemistry, and minimise confounding variables. This led to the selection of four sites within the Celtic Sea that are significantly different in terms of their sediment, bed structure, and macrofaunal, meiofaunal and microbial community structures and diversity, but have minimal variations in water depth, tidal and wave magnitudes and directions, temperature and salinity. They form the basis of a research cruise programme of observation, sampling and experimentation encompassing the spring bloom cycle. Typical variation in key biogeochemical, sediment, biological and hydrodynamic parameters over a pre to post bloom period are presented, with a discussion of anthropogenic influences in the region. This methodology ensures the best likelihood of site-specific work being useful for up-scaling activities, increasing our understanding of benthic biogeochemistry at the UK-shelf scale.