Oceanographic Factors Affecting Seabird Occurrence in the Tropical Pacific Ocean

除了部分浮游动物外，远洋生物群落的生态结构还不为人所知。远洋海洋浮游动物群落的组织可能与底栖生物甚至陆地生物群落不同。海鸟丰度、物种组合、组合稳定性和对栖息地扰动的响应可以比任何其他海洋浮游生物更令人满意地量化。EPOCS计划是一个大型海洋学项目，收集厄尔尼诺事件预测的数据，将用于量化海鸟生态与上层海洋环境的物理因素之间的联系。气候的季节周期性和年际变率、热带太平洋东部已知的复杂水域类型、非候鸟群和EPOCS游轮都提供了自然实验，在这些实验中，构成远洋海鸟群落的因素变得清晰起来。以海面或海面附近的远洋生物为食的海鸟，经常聚集在与洋流和锋面等自然环境的主要特征相一致的海洋特定区域。因为海鸟在远处就能被看到和识别，它们在海洋的一个或另一个区域的数量和存在往往表明一个特定的水域携带着一群特定的远洋生物。在太平洋，最近被称为厄尔尼诺和冷异常的自然变化表明，海鸟在空间上的变化方式与受厄尔尼诺影响的水团相同。鸟类和鸟类种类的分布不仅表明一个地区存在的水团，而且表明浮游生物的种类和丰度，这些浮游生物是鸟类的食物来源。鸟类生态学使我们对海洋过程及其在大尺度上的生物效应有了一个统一的认识。

The ecological structure of pelagic communities is not well known, except for portions of the zooplankton. Pelagic marine zooplankton communities may be organized differently than benthic or even terrestrial communities. Seabird abundance, species assemblages, assemblage constancy, and responses to habitat perturbation can be quantified more satisfactorily than for any other pelagic nektonic organisms. The EPOCS program, a large oceanographic project gathering data for prediction of El Nino events, will be used to quantify the link between seabird ecology and physical factors of the epipelagic environment. Seasonal periodicity and interannual variability of climate, a complex of well known water types in the eastern tropical Pacific, a non-migratory avifauna, and the EPOCS cruises dombine to provide natural experiments in which factors that structure pelagic seabird communities become clear. %%% Seabirds which depend upon pelagic organisms at the surface or near the surface of the sea often are found aggregated in particular areas of the ocean coincident with major features of the physical environment such as currents and fronts. Because seabirds can be seen and recognized at a distance, their abundance and presence in one area of the ocean or another is often indicative of a particular water mass carrying a particular group of pelagic organisms. In the Pacific Ocean, recent natural variation known as El Nino and cold anomalies, have shown that seabirds vary spatially in the same way as water masses influenced by El Nino. The distribution of birds and types of birds indicate not only what water mass is present in an area, but also the kind and abundance of plankton present which are the food resource of the birds. Bird ecology gives us a unifying overview of oceanic processes and their biological effect on the large scale.