SS1.09 Fisheries Population Linkage Spatial and Temporal Variation in Zooplankton
Date: Wednesday, June 12, 2002
Time: 3:15:00 PM
Location: Carson C
 
SprulesWG, University of Toronto, Mississauga, Canada, gsprules@cyclops.erin.utoronto.ca
Gubala, C, , J.C. Headwaters Canada Ltd., Oakville, Canada, headwaters@sprint.ca
Milne, S, , J.C. Hewadwaters Canada Ltd., Oakville, Canada, s_milne@jcheadwaters.com
 
EFFECTS OF LAKE MORPHOMETRY AND BIOLOGY ON SPATIAL INTERACTIONS OF PELAGIC ORGANISMS
image
As part of an ecological study of spatial patterns of pelagic organisms in lakes, we simultaneously deploy multiple continuous sensors, each targeting specific trophic groups from algae to large fish. For zooplankton we use both an optical plankton counter (OPC) and a 710 kHz split-beam acoustic transducer. The OPC counts and sizes organisms as they pass through a light beam traversing the sampling tunnel. The acoustic transducer continuously profiles approximately 20 m of the water column, and total cross-sectional backscattering is taken as an estimate of zooplankton biomass. Data from three lakes in the Algonquin Highlands of Ontario differing in morphometry and fish communities show contrasting patterns in the spatial patterning of zooplankton. Not only are biomass concentrations and size distributions different, but spatial distributions of zooplankton in relation to morphometric features and day/night cycles vary among lakes. Some remarkable spatial patterns of zooplankton, apparently related to wind action through narrow passages, have been noted. These spatial patterns will be described along with implications for energy transfer through food webs in lakes varying in physical and biological features.