SS1.03 Zooplankton Response to Climate Variability
Date: Monday, June 10, 2002
Time: 10:45:00 AM
Location: Lecture Theatre
 
BattenSD, Sir Alister Hardy Foundation for Ocean Science, Nanaimo, Canada, soba@mail.pml.ac.uk
Welch, D, W, Pacific Biological Station, DFO, Nanaimo, Canada, welchd@pac.dfo-mpo.gc.ca
 
LARGE SCALE INTERANNUAL CHANGES IN THE OPEN OCEAN ZOOPLANKTON COMMUNITY OF THE NE PACIFIC
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Continuous Plankton Recorders were deployed in the north east Pacific along a 3500km transect from Alaska to California in the summer of 1997 and then monthly through the spring and summer of 2000 and 2001. The 1997 sampling occurred during an El Nino event, when sea surface temperatures were anomalously warm, while the 2000 and 2001 sampling occurred when sea surface temperatures were close to, or just below, mean values. Zooplankton abundance shows significant interannual variability; overall transect abundances in 1997 were twice the abundance recorded on summer transects in 2000 and in some regions up to six times higher. Furthermore, calanoid copepod species composition changes are also evident; southern species were more abundant and occurred further north in 1997 compared to 2000 and 2001, while northern species were more abundant in the cooler period. Synoptic sampling of the plankton on this scale has been rare in the North Pacific and these surveys provide one of the first opportunities to describe large scale climate induced variability in the plankton community.