Patterns in Zooplankton Distribution and Their Causes in North American Great Lakes

Abstract

A definition of the term “great lake” is proposed based on the midsummer epilimnion depth. Several patterns of zooplankton distribution were discovered in North American great lakes. They were mostly a function of the following five characteristics: temperature distribution (Lake Ontario, Lake Superior, and Great Slave Lake); inflow and outflow configurations (Lake Winnipeg and Great Slave Lake); geology and drainage basin type (Lake Winnipeg and Great Slave Lake); basin morphology (Lake Erie, Lake Superior, and Great Slave L.); climate differences within the system (Lake Winnipeg). A high degree of heterogeneity was characteristic for all of the lakes but each of them developed a specific pattern determined by a specific set of external factors (climate, geology of the drainage area, hydrology) and morphology. These findings contradict some paradigms on great lakes as formulated in the preamble to this symposium. Climate (latitude and air and lake temperature) and lake morphology seem to be the primary factors controlling zooplankton abundance among large lakes. Regressions describing these relationships are presented.KeywordsGreat LakeLarge LakeWater Residence TimeZooplankton AbundanceCrustacean ZooplanktonThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.