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，如西部鹬，在春季和秋季在不列颠哥伦比亚省的海岸进行广泛的季节性迁徙。它们沿着美国南部海岸以及中美洲和南美洲过冬，它们沿着阿拉斯加的北方海岸度夏。这种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“补充燃料”地点供应。罗伯茨银行就是这样一个地点，位于弗雷泽河河口南侧，距温哥华以南35公里。广泛的生物膜社区是已知的罗伯茨银行的暴露的潮间带泥滩上生长，约占总饮食的45 - 68%（每日能量预算的50%）的西方鹬。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，富含一种称为ω-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），已知对所有脊椎动物（包括鸟类）的健康至关重要。特别是，欧米茄-3脂肪酸，如EPA和DHA，已知对维持长距离迁徙如滨鸟的飞行很重要，因此可能对滨鸟迁徙成功至关重要。然而，水的条件（例如盐度、温度）可能具有

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