BENTHIC-PELAGIC COUPLING AT THE SEMI-CLOSED BAY TIDAL FLAT IN TAEAN, KOREA

Abstract

Material flux at the tidal flat is important for the management of marine environments, however, only few information is available in Korea. In the present study, factors concerned in benthic-pelagic coupling such as organic matters mineralization, flux of inorganic nutrients and oxygen consumption rates at the tidal flat sediments and flux of nutrients, phytoplankton and bacteria and primary and secondary production at the mouth of bay during 1 tidal cycle were investigated at the Geunso Bay, a semi-closed bay located in Taean, Korea. Annual average rate of organic matters mineralization via anaerobic process was 35.5 mmol-C m-2 day-1. During the mineralization process efflux of 0.608 mmol-NH4+ m-2 day-1 and 0.197 mmol- NO2- m-2 day-1 into water column and influx of 0.829 mmol-NO3- m-2 day-1 from water column were observed. Bioturbation by benthic animals accelerate the rates up to 3 times via transport 100 times higher oxygen compared to that by passive transport. At the mouth of the bay concentration of nitrate and phosphate was higher in high tide compared than that of ebb tide but the conc. of ammonia was vice versa. Bacterial abundance and production were higher in ebb tide and concurrently changed with the abundance of phytoplankton. The results implied that inorganic nutrients from outer area of the bay support the production in water column and tidal flat in the bay and organic biomass was outwelling from the Bay. [Supported by KORDI in house Program (PE98130)]