부산대학교 도서관

Changing environmental conditions such as decreasing sea ice cover impact Arctic zooplankton. In the Canada Basin, zooplankton surveys have seldom been done due to its traditionally thick, year-round ice cover. Here, we describe the zooplankton community of the Canada Basin before the two recent sea ice minima (2007 and 2012). Zooplankton were sampled from the upper 100 m during August and September of the years 2003–2006 using a 150-μm mesh net to determine species composition, abundance and biomass. To describe the zooplankton community and its relation to the environment, we used Bray–Curtis similarity, and then applied hierarchical clustering, non-parametric multidimensional scaling and the BEST BIO-ENV routine. The most abundant zooplankton species in all years were smaller copepods such as Oithona similis and Microcalanus pygmaeus. Biomass was dominated by larger copepod species such as Calanus hyperboreus and Calanus glacialis. For the non-copepod zooplankton, the pteropod Limacina helicina and the larvacean Fritillaria borealis were typically the most abundant species. The non-copepod biomass was dominated by the chaetognath Eukrohnia hamata and L. helicina , while F. borealis contributed relatively little to the overall biomass despite its high numbers. Zooplankton communities differed between shelf/slope and basin stations. We found no obvious interannual changes in community structure over our short 4-year observation period, with community structure influenced to a small degree by environmental factors. [ABSTRACT FROM AUTHOR]