A Collaborative Study of Prolonged Production and Trophic Transfer to Predators: Processes at the Inner Front of the Southeastern Bering Sea

每年有数百万只短尾剪尾鸥（Puffinus tenuirostris）从澳大利亚迁徙到白令海，在内陆架上觅食。 这种每年一次的跨赤道迁徙的演变意味着白令海的这些鸟类必须随时获得大量的猎物。 1997年和1998年，白令海东部的异常天气模式导致水文和水循环发生重大变化。 由此产生的生态系统异常包括白令海首次记录的颗石藻水华，目前约10%的移民剪水的饥饿，并在1997年和1998年的布里斯托湾红鲑鱼渔业崩溃。 这个研究项目将继续测试的假设，即在白令海东南部的内部前端的初级生产持续时间比在非锋面沃茨，这种生产提供了一个能量来源，整个夏天的食物网，支持剪切沃茨，鲑鱼，和他们的浮游动物猎物。 根据1997年和1998年的调查结果，将利用季节性和年际间的比较来检验关于风暴和营养物质平流作用的其他假设。 这项合作研究将收集和解释内锋附近的物理和生物特征的观测结果，以确定：1）真光层中营养物质的可用性，2）负责营养物质垂直通量增强的物理过程，3）初级生产，4）近地表磷虾和其他大型和微型浮游动物群的分布、丰度和营养生态学，5）剪水的分布、丰度和觅食生态; 6）通过稳定同位素富集，从浮游植物到锋面和远离锋面的剪水的营养途径。白令海东南部支撑着世界上最丰富的渔业之一;狭鳕、鲑鱼、大比目鱼和螃蟹每年产生超过20亿美元的收入。 尽管如此，沿海地区和内锋，那里的剪水，年轻的鲑鱼和一些螃蟹幼虫聚集觅食，还没有得到很好的研究。 这项研究是重要的，因为它将：1）天气模式的变化如何影响影响生态系统功能的物理过程; 2）是夏季内锋物理过程和锋在花后初级生产中的作用的第一次检查;（3）注重扩大生产的生态作用，（4）将海鸟跨赤道迁移模式的演变与生物物理过程联系起来，从而创造可预测的猎物来源。 这些问题的解决，集中在物种和地区的调查人员熟悉，但是，结果可以适用于许多大陆架潮汐前沿和物种。 因此，研究结果应具有普遍适用性，以了解和管理世界上一些最具生产力的海洋。

AbstractHunt U of CA, Irvine 9819251Zeeman U of New England 9907097Whitledge U of AK, Fairbanks 9819273Each year millions of short-tailed shearwaters (Puffinus tenuirostris) migrate from Australia to the Bering Sea to forage over the inner shelf. The evolution of this annual trans-equatorial migration implies that extraordinary amounts of prey must be readily available to these birds in the Bering Sea. In 1997 and 1998, unusual weather patterns in the eastern Bering Sea resulted in significant changes in hydrography and water circulation. The resultant ecosystem anomalies included the first recorded coccolithophore bloom in the Bering Sea, the starvation of about 10% of the migrant shearwaters present, and the collapse in both 1997 and 1998 of the Bristol Bay sockeye salmon fishery. This research project will continue testing the hypothesis that elevated primary production at the inner front of the southeastern Bering Sea continues longer than in non-frontal waters, and that this production provides an energy source throughout the summer for a food web that supports shearwaters, salmon, and their zooplankton prey. Based on findings in 1997 and 1998, additional hypotheses concerning the roles of storms and advection of nutrients will be tested using seasonal and inerannual comparisons. This collaborative study will collect and interpret observations on physical and biological features in the vicinity of the inner front to determine: 1) the availability of nutrients in the euphotic zone, 2) the physical processes responsible for enhanced vertical flux of nutrients, 3) primary production, 4) the distribution, abundance and trophic ecology of near-surface swarms of euphausiids and other macro- and micro-zooplankton, and 5) the distribution, abundance, and foraging ecology of shearwaters, and 6) by stable isotope enrichment, trophic pathways from phytoplankton to shearwaters at and away from the front.The southeastern Bering Sea supports one of the world's richest fisheries; walleye pollock, salmon, halibut and crab generate over 2 billion dollars in revenue each year. Despite this, the coastal domain and inner front, where shearwaters, young salmon and some crab larvae congregate to forage, has not been well studied. The study is important because it will: 1) relate how variation in weather patterns forces physical processes that affect ecosystem function; 2) be the first examination of the physical processes of the inner front during summer and of the role of the front in post-bloom primary production; 3) focus on the ecological role of the extended production, and 4) relate the evolution of trans-equatorial migration patterns of seabirds to biophysical processes that create predictable sources of prey. These questions are addressed by focusing on species and regions with which the investigators are familiar; however, the results can be applied to numerous continental shelf tidal fronts and species. Thus, the results should have a general applicability to understanding and managing some of the world's most productive seas.