Relationships between oceanic epizooplankton distributions and the seasonal deep chlorophyll maximum in the northwestern Atlantic Ocean
MetadataShow full item record
The potential significance of the Deep Chlorophyll Maximum (DCM) as a food resource for pelagic food chains was studied in three hydrographic regimes of the Northwestern Atlantic Ocean: the Slope Water, the Northern Sargasso Sea and a Gulf Stream cold core ring. Samples for phytoplankton species, chlorophyll and related water chemistry were obtained with a series of water bottle casts from the upper 200 m; microzooplankton and macrozooplankton were also obtained in the upper 200 m with Clarke Bumpus (67 m mesh) and MOCNESS (333 m mesh) net systems. Samples were obtained in the summer when the DCM was well developed and in the fall when mixing had erased the DCM in most areas. Total zooplankton biomass was significantly enhanced within depth intervals including or adjacent to the seasonal thermocline in the three hydrographic areas. Hydrocast data show the DCM in these regions was predictably associated with the seasonal thermocline. Thus these data indicate zooplankton biomass was enhanced about the DCM when it was present. In some cases, the zooplankton assemblage at DCM depths was distinguishable from those both at deeper and more shallow depths and its composition appeared related to the food available at DCM depths. Overall, in environments ranging from moderately rich near-shore Slope Waters to the more oligotrophic open-ocean Sargasso Sea, our data suggest that the DCM signals a depth zone of particularly intense trophic activity.
Also published as: Journal of Marine Research 38 (1980): 507-531
Suggested CitationOrtner, P. B., Wiebe, P., & Cox, J. L. (1981). Relationships between oceanic epizooplankton distributions and the seasonal deep chlorophyll maximum in the northwestern Atlantic Ocean. Woods Hole Oceanographic Institution. https://doi.org/10.1575/1912/10245
Showing items related by title, author, creator and subject.
Gaube, Peter; McGillicuddy, Dennis J.; Chelton, Dudley B.; Behrenfeld, Michael J.; Strutton, Peter G. (John Wiley & Sons, 2014-12-01)Eddies can influence biogeochemical cycles through a variety of mechanisms, including the excitation of vertical velocities and the horizontal advection of nutrients and ecosystems, both around the eddy periphery by ...
Satellite observations of chlorophyll, phytoplankton biomass, and Ekman pumping in nonlinear mesoscale eddies Gaube, Peter; Chelton, Dudley B.; Strutton, Peter G.; Behrenfeld, Michael J. (John Wiley & Sons, 2013-12-02)Nonlinear mesoscale eddies can influence biogeochemical cycles in the upper ocean through vertical and horizontal advection of nutrients and marine organisms. The relative importance of these two processes depends on the ...
Seasonal variation in the correlation between anomalies of sea level and chlorophyll in the Antarctic Circumpolar Current Song, Hajoon; Long, Matthew C.; Gaube, Peter; Frenger, Ivy; Marshall, John; McGillicuddy, Dennis J. (John Wiley & Sons, 2018-05-30)The Antarctic Circumpolar Current has highly energetic mesoscale phenomena, but their impacts on phytoplankton biomass, productivity, and biogeochemical cycling are not understood well. We analyze satellite observations ...