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Seasonal Cycles of Zooplankton and Related Phytoplankton Development in Three Shallow, Mesotrophic Lakes in Northern Canada
Author(s) -
Moore James W.
Publication year - 1980
Publication title -
internationale revue der gesamten hydrobiologie und hydrographie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 0020-9309
DOI - 10.1002/iroh.19800650307
Subject(s) - cyclops , zooplankton , phytoplankton , plankton , temperate climate , ecology , subarctic climate , biology , population , population density , environmental science , oceanography , nutrient , demography , sociology , geology
The primary goal of this study was to assess the importance of food in regulating densities of zooplankton in 3 northern Canadian lakes, where algal availability was low compared to temperate zone water bodies. Collections were made every 2 weeks during the summer and monthly during the winter from April 1978 to April 1979. Since the lakes were similar in most respects, including nannoplankton density, net phytoplankton density, temperature, depth, oxygen concentration and phosphorus levels, the seasonal cycles of the main species (Keratella cochlearis, Kellicottia longispina, Polyarthra remata, Polyarthra vulgaris, Cyclops spp., Diaptomus spp.) were generally similar throughout the study area. Changes in the densities of herbivorous species were poorly correlated with fluctuations in nannoplankton and net plankton availability, implying that food did not limit development. Although predatory copepods, particularly Cyclops spp., were abundant, they also had no measurable impact on the main species. It was therefore concluded that temperature controlled the seasonal cycles and the ultimate population size of most zooplankters.