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.

A preliminary investigation of basin water response to climate forcing in a Scottish fjord: evaluating the influence of the NAO

Abstract: The sea lochs (fjords) of NW Scotland bridge the land–ocean interface in a region of Europe which is particularly well situated to monitor changes in westerly air streams Inter-annual atmospheric circulation changes at this latitude are largely governed by the North Atlantic Oscillation (NAO) Comparing two recent extreme NAO years, a two-dimensional model of Loch Sunart, NW Scotland, is used to examine the potential effects of climate oscillations on the magnitude and frequency of deep-water renewal events and the resulting water properties in the fjord basins In the upper basin of the fjord, meteorological forcing during the high NAO index year (1988–89) resulted in less-frequent deep-water renewal, greater variability in basin salinity and a lower annual-mean salinity (by 052) than that predicted for the low NAO index year (1995–96) In the main basin, variations in meteorological forcing had much less effect on basin water properties In both basins, predicted deep water inflow was significantly greater during the negative phase NAO, with annual inflow to the upper and main basins being respectively 50% and 300% greater during 1995–96 relative to 1988–99 Through a sensitivity analysis, the NAO is shown to affect upper basin water properties through the influence of low-frequency anomalies in the meteorological forcing, particularly the enhanced westerly wind stress associated with positive phases, which inhibits deep water renewal over the winter months The salinity of the main and upper basins respond differently to the boundary forcing due to differential tidal mixing above the respectively sub- and super-critical entrance sills Predictions of basin water isotope ratios are made by applying the salinity: δ 18 O water mixing line for the region to the salinity results; the combination of the weak dependence of δ 18 O water on salinity and the stable salinity predicted for the main basin suggests that some fjord basins may provide ideal sites for palaeotemperature studies

Modelling potential production of macroalgae farms in UK and Dutch coastal waters

Abstract: . There is increasing interest in macroalgae farming in European waters for a range of applications, including food, chemical extraction for biofuel production. This study uses a 3-D numerical model of hydrodynamics and biogeochemistry to investigate potential production and environmental effects of macroalgae farming in UK and Dutch coastal waters. The model included four experimental farms in different coastal settings in Strangford Lough (Northern Ireland), in Sound of Kerrera and Lynn of Lorne (north-west Scotland) and in the Rhine plume (the Netherlands), as well as a hypothetical large-scale farm off the UK north Norfolk coast. The model could not detect significant changes in biogeochemistry and plankton dynamics at any of the farm sites averaged over the farming season. The results showed a range of macroalgae growth behaviours in response to simulated environmental conditions. These were then compared with in situ observations where available, showing good correspondence for some farms and less good correspondence for others. At the most basic level, macroalgae production depended on prevailing nutrient concentrations and light conditions, with higher levels of both resulting in higher macroalgae production. It is shown that under non-elevated and interannually varying winter nutrient conditions, farming success was modulated by the timings of the onset of increasing nutrient concentrations in autumn and nutrient drawdown in spring. Macroalgae carbohydrate content also depended on nutrient concentrations, with higher nutrient concentrations leading to lower carbohydrate content at harvest. This will reduce the energy density of the crop and thus affect its suitability for conversion into biofuel. For the hypothetical large-scale macroalgae farm off the UK north Norfolk coast, the model suggested high, stable farm yields of macroalgae from year to year with substantial carbohydrate content and limited environmental effects.

Intercalibration studies of short-lived thorium-234 in the water column and marine particles

Abstract: Intercomparision of 234 Th measurements in both water and particulate samples was carried out between 15 laboratories worldwide, as a part of GEOTRACES inter-calibration program. Particulate samples from four dif ferent stations namely BATS (both shallow and deep) and shelf station (shallow) in Atlantic and SAFE (both shallow and deep) and Santa Barbara station (shallow) in Pacific were used in the effort. Particulate intercali bration results indicate good agreement between all the participating labs with data from all labs falling with in the 95% confidence interval around the mean for most instances. Filter type experiments indicate no signif icant differences in 234 Th activities between filter types and pore sizes (0.2‐0.8 µm). The only exception are the

Chemically-Mediated Interactions Between Macroalgae, Their Fungal Endophytes, and Protistan Pathogens.

Abstract: Filamentous fungi asymptomatically colonize the inner tissues of macroalgae, yet their ecological roles remain largely underexplored. Here, we tested if metabolites produced by fungal endophytes might protect their host against a phylogenetically broad spectrum of protistan pathogens. Accordingly, the cultivable fungal endophytes of four brown algal species were isolated and identified based on LSU and SSU sequencing. The fungal metabolomes were tested for their ability to reduce the infection by protistan pathogens in the algal model Ectocarpus siliculosus. The most active metabolomes effective against the oomycetes Eurychasma dicksonii and Anisolpidium ectocarpii, and the phytomixid Maullinia ectocarpii were further characterized chemically. Several pyrenocines isolated from Phaeosphaeria sp. AN596H efficiently inhibited the infection by all abovementioned pathogens. Strikingly, these compounds also inhibited the infection of nori (Pyropia yezoensis) against its two most devastating oomycete pathogens, Olpidiopsis pyropiae, and Pythium porphyrae. We thus demonstrate that fungal endophytes associated with brown algae produce bioactive metabolites which might confer protection against pathogen infection. These results highlight the potential of metabolites to finely-tune the outcome of molecular interactions between algae, their endophytes, and protistan pathogens. This also provide proof-of-concept toward the applicability of such metabolites in marine aquaculture to control otherwise untreatable diseases.