EARLY REPRODUCTION BY CALANUS GLACIALIS IN THE NORTHERN BERING SEA: THE ROLE OF SEA ICE AS REVEALED BY MOLECULAR ANALYSIS
Calanus glacialis initiated feeding and reproduction under extensive sea ice in the northern Bering Sea during late winter despite very low average water column chlorophyll a concentrations. Estimated egg production rates were between 0 and 12 eggs F-1 Day-1. Ingestion rates estimated from gut pigments were between 0.14 and 15.5 % Body C Day-1 and were strongly correlated with surface chlorophyll. The dominant prey species in the guts of C. glacialis, the ice algal diatoms, Fragilariopsis cylindrus, Fragilaria sp. and Pseudo-nitzschia sp., were quantified by qPCR and species-specific ingestion rates estimated. The total of these was strongly correlated (r2 =0.93) with, and similar to, those estimated from gut pigments. Feeding and reproduction was significantly related to air temperature lagged by 2 or 3 days and stimulated by a release of ice algae into the water column when air temperatures were warmer. The availability of ice algae over an extended period during colder winters will lead to a longer reproductive period and larger population sizes of C. glacialis compared with warmer years with less extensive ice cover.
Durbin, E. G., University of Rhode Island/Graduate School of Oceanography, USA, firstname.lastname@example.org
Casas, M. C., University of Rhode Island/Graduate School of Oceanography, USA, email@example.com
Location: 316 B
Presentation is given by student: No