SEASONAL CYCLES IN THE CARNIVOROUS CALANOID COPEPOD EUCHAETA NORVEGICA

Copepods are the most abundant metazoan on the planet. They serve as a trophic conduit  between primary production and some secondary consumption in the marine food web. Their seasonal abundance and distribution directly influence the productivity of higher trophic levels, including fish populations and marine mammals. While much is known about herbivorous calanoids, little is known about seasonal cycles of carnivorous copepods. For this study we collected monthly samples in the Gulf of Maine at approximately 30 nautical miles from shore. We conducted integrated net tows from approximately 170 meters to the surface using a bongo net with a 200 micron mesh. Samples were processed to identify and enumerate developmental stage, number of egg-bearing females, and female/male ratio. The data shows peaks in egg production during  April, July and October. Peaks in the CII-CIII stage abundances indicate that eggs potentially hatched in October require 2 to 3 winter months for development to copepodite stages. The data shows a strong correlation between the abundance of egg-bearing females and the female/male ratio. We found no relationship between the abundances in E. norvegica and the total zooplankton biomass sampled.

Presentation Preference: Oral

Primary Presenter: Claire Fecteau-Volk, University of New England (volkclaire@gmail.com)

Authors:

Claire Fecteau-Volk, University of New England, Bigelow Laboratory for Ocean Sciences  (volkclaire@gmail.com)

Maura Niemisto, Bigelow Laboratory for Ocean Sciences  (mniemisto@bigelow.org)

David Fields, Bigelow Laboratory for Ocean Sciences  (dfields@bigelow.org)