Department of Biosiences, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Section Polar Biological Oceanography, Bremerhaven, Germany.
Institute for Chemistry and Biology of the Marine Environment, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
Nat Ecol Evol. 2017 Dec;1(12):1853-1861. doi: 10.1038/s41559-017-0368-3. Epub 2017 Nov 13.
A dominant Antarctic ecological paradigm suggests that winter sea ice is generally the main feeding ground for krill larvae. Observations from our winter cruise to the southwest Atlantic sector of the Southern Ocean contradict this view and present the first evidence that the pack-ice zone is a food-poor habitat for larval development. In contrast, the more open marginal ice zone provides a more favourable food environment for high larval krill growth rates. We found that complex under-ice habitats are, however, vital for larval krill when water column productivity is limited by light, by providing structures that offer protection from predators and to collect organic material released from the ice. The larvae feed on this sparse ice-associated food during the day. After sunset, they migrate into the water below the ice (upper 20 m) and drift away from the ice areas where they have previously fed. Model analyses indicate that this behaviour increases both food uptake in a patchy food environment and the likelihood of overwinter transport to areas where feeding conditions are more favourable in spring.
一种占主导地位的南极生态范式表明，冬季海冰通常是磷虾幼虫的主要觅食地。我们在南大洋西南亚南极区进行的冬季航行的观测结果与这一观点相矛盾，首次表明，冰架区是幼虫发育的食物贫瘠生境。相比之下，更开阔的边缘冰区为幼虫磷虾提供了更有利的食物环境，使其生长速度更快。我们发现，当水柱生产力受到光照限制时，复杂的冰下生境对于磷虾幼虫至关重要，因为这些生境提供了免受捕食者侵害的结构，并收集从冰中释放的有机物质。幼虫在白天以这种稀疏的冰相关食物为食。日落后，它们会迁移到冰下的水中（上层 20 米），并远离它们之前进食的冰区。模型分析表明，这种行为增加了在斑块状食物环境中的食物摄取量，以及在春季更有利于觅食条件的地区越冬运输的可能性。
