Temperature-dependent allometric models to estimate zooplankton production in temperate freshwater lakes

Abstract

Empirical relationships between body size and temperature, and daily P/B of temperate freshwater zooplankton species were derived from the literature. Body size explained 81% of the variation in daily P/B of zooplankton at temperatures <<= 10°C and 48% at temperatures >10°C. The two relationships did not differ in slope but significantly differed in elevation. The regression models were then applied to zooplankton samples collected from a midlake station in Lake Ontario to predict zooplankton seasonal production. Production estimates from the regression models, when compared with estimates from the egg ratio method for the same data set, were similar for cladoceran species, four and 10 times higher for two copepod species, and two times higher for total zooplankton production. In general, these differences are within the range expected based on previous studies that compared different production models. The regression models can provide quick, independent estimates of zooplankton production to complement estimates based on traditional, species-specific methods. Furthermore, the models can be used in conjunction with automated synoptic instruments, such as optical plankton counters and temperature probes, to provide production estimates that better represent large, complex systems such as the Great Lakes.