Omega-3 fatty acids in diatom-dominated biofilms in the Fraser River Estuary: Quantifying nutrient sources for migratory bird populations

许多海岸鸟类，如西部矶鹞，在春季和秋季在不列颠哥伦比亚省的海岸上下进行广泛的季节性迁徙。它们在美国南部海岸、中美洲和南美洲度过冬天，在阿拉斯加北部海岸度过夏天。这样的长途旅行需要热量和营养丰富的食物，这些食物在非常特定的“加油”地点供应。罗伯茨银行（Roberts Bank）就是这样一个地方，它位于弗雷泽河（Fraser River）河口南侧，距离温哥华以南35公里。已知在罗伯茨滩暴露的潮间带泥滩上生长着广泛的生物膜群落，约占西方矶鹬总饮食的45 - 68%（每日能量预算的50%）。这些生物膜群落由一组称为硅藻的藻类主导。众所周知，硅藻富含能量和营养，并且富含一种叫做omega-3脂肪酸的脂质（脂肪）；包括两种脂肪酸，二十碳五烯酸（EPA）和二十二碳六烯酸（DHA），这两种脂肪酸对包括鸟类在内的所有脊椎动物的健康都是必不可少的。特别是，omega-3脂肪酸，如EPA和DHA，被认为对维持像滨鸟这样的长途迁徙者的飞行很重要，因此可能对滨鸟的迁徙成功至关重要。然而，水的条件（例如盐度，温度）可能有一个

Many shore birds, such as Western Sandpipers, make extensive seasonal migrations up and down the coast of British Columbia in spring and fall. They spend their winters along the southern coasts of the US, and in Central and South America and they spend summer along the northern coasts of Alaska. Such long distance journeys require calorie- and nutrient-rich foods and which are supplied at very specific "re-fueling" locations. One such location is Roberts Bank situated on the south side of the estuary of the Fraser River ~35 kilometers south of Vancouver. Extensive biofilm communities are known to grow on the exposed intertidal mudflats in Roberts Bank and which account for approximately 45 - 68% of the total diet (50% of daily energy budgets) of Western Sandpipers. These biofilm communities are dominated by a group of algae called diatoms. Diatoms are known to be high in energy and nutrients and are rich in a type of lipid (fat) called omega-3 fatty acids; including two fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), that are known to be essential for the health of all vertebrates including birds. In particular, omega-3 fatty acids, like EPA and DHA, are known to be important to sustain flight of long-distance migrants such as shorebirds, and may therefore be critical for shorebird migration success. However, water conditions (e.g. salinity, temperature) may have a