Production of Acartia omorii (Copepoda : Calanoida) in Ilkwang Bay, southeastern coast of Korea

Abstract

Production of the marine calanoid copepod Acartia omorii was measured from 2 October 1991 to 8 October 1992 at a station in Ilkwang Bay on the southeastern coast of Korea. A. omorii (nauplii+copepodites+adults) were present in the plankton throughout the year, with seasonal variation in abundance. Biomass of A. omorii was averaged at 0.44 mgC m 3, with peaks in February and July, and relatively low biomass in late summer and fall. Egg production rate ranged from 2.4 to 151.9 pgC m(-3) day(-1), which was equivalent to 95-6075 eggs m 3 day(-1). Fecundity of an adult female was averaged at 38 eggs female(-1) day(-1). Instantaneous growth rates of copepodites were higher than those of nauplii stages. Annual production of A. omorii ranged from 33.5 mgC m(-3) year(-1) to 221 mgC m(-2) year(-1), showing a seasonal variation of daily production rate with peaks in February and July. The daily production rate of A. omorii was significantly correlated with chlorophyll a concentration. These results suggest that standing stocks and/or productivity of phytoplankton are the major influencing factors, rather than water temperature for the seasonal variation of production of A. omorii in Ilkwang Bay. (c) 2006 Elsevier B.V. All rights reserved.