Distribution of Larval Krill, Zooplankton, and Particulates in Association with Hydrography in the Water Column of the Continental Shelf near Marguerite Bay, Antarctic Peninsula, described using the Video Plankton Recorder

Carin J. Ashjian, Cabell S. Davis, Scott M. Gallager, and Peter H. Wiebe

High resolution vertical and horizontal descriptions of the distribution of plankton, especially larval krill, relative to water column hydrography were obtained between ~10 and 250 m on all four Southern Ocean GLOBEC cruises using the Video Plankton Recorder mounted on the BIOMAPERII. Images of plankton were extracted from the video stream in real time and were identified automatically to taxa during the cruises. During 2001, greatest abundances of plankton were observed during the fall cruise, with much reduced abundances during winter. Greatest abundances of larval krill were observed in association with the pycnocline. During the fall 2002 cruise, high abundances of marine snow particles were observed early in the cruise, particularly across the northern sections of the survey. Many of these particles were easily identified as conglomerations of diatom chains known as algal mats. A repeat survey of line 2 in the northern area of the study site at the end of the cruise showed only typical marine snow particles and no algal mats.