Growth, mortality, and secondary production of the copepod Acartia tranteri in Westemport Bay, Australia1

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Abstract
We measured the growth rate of Acartia tranteri and related variables in Westernport Bay, Australia, on 19 occasions in 1982–1984. Acartia tranteri is numerically dominant in the bay zooplankton, with a mean abundance of all life stages of 12,000 m−3. Growth rates, measured by an incubation method, varied between 0.025 and 0.26 d−1 with a time‐weighted mean of 0.11 d and chlorophyll concentrations together explained 50% of the variance in growth rate, which was usually food limited.Annual secondary production of A. tranteri was 130 mg C m−3, < 1% of phytoplankton primary production. Zooplankton production is a minor constituent of the energy budget of the bay, compared to benthic production.Mortality rates, estimated from stage abundances and development times, were very low except in early naupliar stages. Median adult longevity was 26 d when water temperature was 20°C. The low mortality and high longevity are consistent with the observed low abundances of planktonic predators and with the low consumption rates of Acartia by planktivorous fish in the bay.