BEST: Sea Ice algae, a major food source for herbivorous plankton and benthos in the eastern Bering Sea.

为研究海冰藻类在东白令海陆架生态系统食物网中的作用提供了资金。 从白令海获得的稀少观测资料表明，冰藻产量可能高达浮游植物产量的30%;在冰层覆盖期间，冰藻生物量几乎与综合浮游藻类生物量一样高。这一提议的首要假设是，海冰藻类是春季浮游和底栖食草动物的主要食物来源，特别是在冰融化期间。在处理这一假设时，本提案旨在提供资料，说明海冰藻类和冰下浮游植物的丰度、生物量、群落组成和生产力的空间和时间模式与物理和化学环境的关系。环境测量将包括冰芯和冰下水的盐度、温度和营养物浓度，以及冰的厚度、积雪和光照状况。沉积物，稳定同位素比值（d13 C，d15 N）和藻类群落组成将被用作三条证据线，以跟踪冰藻生产的命运，通过水层和白令海的底栖食物网。在不同冰盖状态下进行的实地工作将通过对浮游和底栖食草动物的实验工作得到加强，从而首次对白令海无脊椎动物的稳定同位素周转率进行测量。综合数据集将允许在白令海的食物网结构的海冰产生的有机物的相关性的一个精细的解释。这个项目是一个更大的计划，旨在发展的理解白令海大陆架东部，美国沿海沃茨的一个高产地区的综合生态系统的一部分。 这个生态系统是美国商业渔业的主要部分，也为阿拉斯加的猎人和渔民提供了重要的资源。 了解海冰藻类在该系统中的作用对于能够预测该系统如何以及为什么会对海冰条件的变化做出反应至关重要，例如近年来已经观察到的变化。

Funds are provided to study the role of sea ice algae in the food web of the eastern Bering Sea shelf ecosystem. The scarce observations available from the Bering Sea indicate that ice algal production may be as high as 30% of the phytoplankton production; during times of ice cover, ice algal biomass can be nearly as high as integrated pelagic algal biomass. The overarching hypothesis of this proposal is that sea ice algae are the major food source for pelagic and benthic herbivores in spring, specifically during periods of ice melt. In addressing this hypothesis, this proposal aims at providing information on the spatial and temporal patterns of abundance, biomass, community composition and productivity of sea ice algae and phytoplankton just below the ice in relation to the physical and chemical environment. Environmental measurements will include salinity, temperature, and nutrient concentrations in ice cores and under-ice water, as well as ice thickness, snow cover and light regime. Sedimenting material, stable isotope ratios (d13C, d15N) and algal community composition will be used as three lines of evidence to follow the fate of ice algal production through the pelagic and into the benthic food web of the Bering Sea. Field work conducted during different ice cover regimes will be augmented with experimental work on pelagic and benthic herbivores, producing the first-ever stable isotope turnover rate measurements for any Bering Sea invertebrates. The combined data set will allow for a refined interpretation of the relevance of the sea ice produced organic matter for the food web structure in the Bering Sea.This project is part of a larger program designed to develop understanding of the integrated ecosystem of the eastern Bering Sea shelf, a highly productive region of US coastal waters. This ecosystem is home to a major portion of the commercial fisheries of the US and also provides significant resources to subsistence hunters and fisherman of Alaska. Understanding role of sea ice algae in this system is essential to being able to predict how and why the system may respond to changes in sea ice conditions, such as have been observed in recent years.