We combined the use of pigments, fatty acids and sterols as biomarkers of the seasonal variation in food sources of the great scallop Pecten maximus. From March to October 2011, on a biweekly to twice-weekly basis, scallops and seawater from the water column and the water-sediment interface were collected in the Bay of Brest (Brittany, France). Pigment compositions in the seawater and in the stomach and rectum content of the scallops were analyzed by HPLC. Fatty acids and sterols from digestive gland (DG) tissue were analyzed by gas chromatography. Potential relationships between the temporal proportion of each marker in the environment and in the digestive tract were tested using multivariate analysis. Proportions of diatoms and Dinophyceae biomarkers alternated in the digestive tract of P. maximus. This switch of feeding was confirmed by the polar lipid composition of the DG. Peridinin, characterizing Dinophyceae, occurred in high proportions in the digestive tract compared to the low ambient concentration, suggesting a selection of this microalgae group by the scallop. Chlorophyceae and green macroalgae tracers were found in low proportions, suggesting they were not actually ingested. Markers of Prymnesiophyceae were also observed at significant levels. Cyanobacteria tracers showed that this microalgae class was not ingested by the scallops during monitoring but may be of higher importance during winter. Switching from one food source to another as well as selectivity in feeding are discussed relative to the season.
1. Environmental change and anthropogenic pressure are primary drivers of biodiversity loss, particularly in wetland ecosystems that have been modified significantly. Among wetland specialists, mammals may be particularly vulnerable to extinction. We aimed to increase understanding of threats and knowledge gaps faced by 11 mammal species inhabiting wetlands throughout India. 2. We adopted a systematic literature search protocol following an evidencebased conservation approach to obtain information on conservation threats and identify knowledge gaps for each species. Each species received threat scores based on the occurrence and magnitude of ecological and anthropogenic threats, a score based on its International Union for Conservation of Nature (IUCN) Red List category, and a knowledge gap score. A cumulative conservation threat score based on the four individual scores was calculated for each species to assess overall conservation threats. 3. Only about 10% of the literature search results were relevant. Of the major research categories, ecology was the most well-studied, whereas the impact of anthropogenic pressure on wetland mammals was the least studied. Pressing ecological and anthropogenic threats, scientific knowledge gaps, and conservation needs contributed to a high cumulative threat score for the sangai Rucervus eldii eldii (cumulative threat score = 34), followed by the wild Asian buffalo Bubalus arnee (threat score = 33) and the Bengal marsh mongoose Herpestes palustris (threat score = 32). Poaching/hunting, habitat loss due to development, and changes in land-use practices were found to be the major anthropogenic threats resulting in decreasing population trends. We identified knowledge gaps concerning the ecology of wetland mammals (e.g. population abundance). It is essential that these knowledge gaps are filled for effective conservation planning. 4. We identified important areas (population ecology, disease ecology, humanwildlife conflict, changes in land use) that should be considered as research priorities for wetland mammals in India, in order to make conservation efforts more effective and enable management planning, to ensure the long-term survival of these mammals. ZUSAMMENFASSUNG AUF DEUTSCH 1. Umweltveränderungen und anthropogener Druck sind Haupttreiber für den Verlust der biologischen Vielfalt, insbesondere in Feuchtgebieten, die erhebliche ökosystemare Veränderungen erfahren haben. Unter den Feuchtgebietsspezialisten sind Säugetiere möglicherweise besonders vom Aussterben bedroht. Ziel unserer Studie war es, das Verständnis von Bedrohungen und Wissenslücken für 11 Säugetierarten in Feuchtgebieten Indiens zu verbessern.
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