Arctic Investigations of Some Factors that Control the Vertical Distributions and Swimming Activities of Zooplankton

摘要

The vertical distributions and movements of zooplankton populations in arctic lakes and ponds were studied. Populations did not undergo diel vertical migrations under continuous light or under long day photoperiods with dark nights. Extreme temperatures depressed the population mean depth, and diel temperature fluctuations could cause vertical movements in pond and column populations. A diel cycle was observed in the swimming rates of zooplankton populations exposed to both continuous light and long day photoperiods, with highest rates in the afternoon and sometimes in the morning.