Sea Ice: An Important Seasonal Habitat for Marine Invertebrate Juveniles in Arctic Fast Ice Systems?

目前，北极大部分沿海地区每年至少有几个月出现海冰覆盖。 这些冰是冰内和冰下高度专业化的独特群落的栖息地。 与冰有关的食物网延伸到更高的营养层次，如海底居民、海豹和北极熊，因此，将海冰、水层和底栖领域密切联系在一起。 海冰覆盖的质量和持续时间在十年时间尺度上变化很大。 为了预测未来冰盖的变化如何影响北极生态，需要更好地了解海冰目前的作用。 因此，提供资金，以加强了解近岸北极海冰在海洋底栖无脊椎动物的生命周期中的作用，重点是多毛类动物。由于相信海冰是北极近岸某些多毛类物种幼年阶段的首选栖息地，PI将检验以下假设：在整个海冰季节，多毛类在海冰和水柱中的密度相同。他们相信，海冰为某些多毛类物种的幼年阶段提供了比水柱更好的生长条件，他们将测试这样一个假设，即多毛类在整个海冰季节的海冰和水柱中具有相同的生长和进食速率。他们相信，海冰盐水通道系统中普遍存在的极端环境条件的影响被相对于水柱的更好的总体生长条件所抵消，他们将检验两个假设：a）在海冰中存在的环境盐度下多毛类动物的死亡率等于正常海水盐度下的死亡率，（B）生活在水柱和海冰中的多毛类的生长和死亡之和相同。

A large fraction of Arctic coastal seas currently exhibits a sea ice cover for at least several months per year. This ice serves as a habitat for highly specialized, distinct communities inside and at the underside of the ice. The ice-related food web extends to higher trophic levels such as sea-floor dwellers, seals, and polar bears and, therefore, closely ties the sea ice, pelagic and benthic realms together. The quality and duration of the sea ice cover varies significantly on decadal time scales. In order to predict how future variations in ice cover might affect arctic ecology, a better knowledge of the present role of sea ice is needed. Therefore, funds are provided to enhance understanding of the role of near-shore Arctic sea ice in the life cycle of marine benthic invertebrates with a focus on polychaetes.Hypotheses to be tested concern three issues:1. Believing that sea ice is the preferred habitat for young stages of certain polychaete species in the Arctic nearshore, the PIs will test the hypothesis that polychaetes occur in the same densities in sea ice and the water columnthroughout the sea ice season.2. Believing that sea ice provides better growing conditions for young stages of certain polychaete species than the water column, they will test the hypothesis that polychaetes have the same growth and feeding rates in sea ice and the water column throughout the sea ice season.3. Believing that the effects of extreme environmental conditions prevailing in the sea ice brine channel system are outweighed by better overall growing conditions relative to the water column, they will test the two hypotheses that a) polychaete mortality at ambient salinities present in sea ice is equal to that at normal seawater salinity, and b) the sum of growth and mortality is the same in polychaetes inhabiting the water column and the sea ice.