Zooplankton communities of the Arctic's Canada Basin: the contribution by smaller taxa

Zooplankton was sampled at ten stations in the Canada Basin during August 2002 using both 53- and 236-mum mesh nets to examine the contribution by smaller and less studied species. Copepod nauplii, the copepods Oithona similis, Oncaea borealis and Microcalanus pygmaeus, and the larvacean Fritillaria borealis typica dominated the upper 100 m of the water column numerically, while biomass was dominated by the copepods Calanus hyperboreus, Calanus glacialis and Paraeuchaeta glacialis, and the chaetognath Eukrohnia hamata. Zooplankton biomass ranged from 3.7 to 14.5 mg AFDW m(3), with a mean of 9.6 mg AFDW m(3). While the three microcopepods contributed less than 5% of the biomass, estimates of their potential growth rates suggest they might contribute upwards of 25% of the metazoan zooplankton production. The true rates of growth and development of these microcopepods in the Arctic need to be determined to conclusively ascertain their importance.