한국 남해동부 연안 일광만의 요각류 Acartia omorii의 생산력

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. steueri (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 seasons. Egg production rate ranged from 2.4 to 151.9 μgC 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 nauplii stages. Annual production of A. omorii was 33.5 mgC m-3 yr-1 or 221 mgC m-2 yr-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 productivity of phytoplankton may be a major controlling factor for the seasonal variation of production of A. omorii in Ilkwang Bay rather than water temperature.