2013년 황해에서 크기별 동물플랑크톤 생물량의 시공간적 변이 및 주요 요각류의 섭식률

Abstract

We estimated size-fractionated zooplankton biomass and feeding experiments of the copepod Calanus sinicus in the offshore waters where Yellow Sea Bottom Cold Waters formed in the Yellow Sea in 2013, in order to understand how existence of the cold waters affects spatial and temporal characteristics of zooplankton dynamics. Zooplankton was size-fractionated using sieves into 0.2-0.5mm, 0.5-1mm, 1-2mm, 2-5mm and >5mm groups, and balance method was chosen to analyze prey items fed by C. sinicus in spring and summer. Average integrated biomass was 142.60 mg/m3 (April) and 117.60 mg/m3 (August). Biomass of three groups (1-2mm, 2-5mm, >5mm) dominated total zooplankton biomass in spring, whereas two groups (0.2-0.5mm and 0.5-1mm) dominated relatively at each depth in summer. Biomass (>2mm) was mainly dominated by C. sinicus and Euphausia pacifica. Latitudinal distribution of size-fractionated zooplankton biomass in spring was affected by the physical features, whereas that in summer was not likely to be affected by subsurface chlorophyll-a maximum. C. sinicus grazed mostly netplankton (>20㎛) during the spring bloom period, while C. sinicus fed mostly nano-sized, and micro-sized ciliates and heterotrophic donoflagellates in summer. These results indicated biomass and prey selectivity of zooplankton was likely related to the physical and biological properties of the cold waters in the Yellow Sea.he cold waters affects spatial and temporal characteristics of zooplankton dynamics. Zooplankton was size-fractionated using sieves into 0.2-0.5mm, 0.5-1mm, 1-2mm, 2-5mm and >5mm groups, and balance method was chosen to analyze prey items fed by C. sinicus in spring and summer. Average integrated biomass was 142.60 mg/m3 (April) and 117.60 mg/m3 (August). Biomass of three groups (1-2mm, 2-5mm, >5mm) dominated total zooplankton biomass in spring, whereas two groups (0.2-0.5mm and 0.5-1mm) dominated relatively at each depth in summer. Biomass (>2mm) was mainly dominated by C. sinicus and Euphausia pacifica. Latitudinal distribution of size-fractionated zooplankton biomass in spring was affected by the physical features, whereas that in summer was not likely to be affected by subsurface chlorophyll-a maximum. C. sinicus grazed mostly netplankton (>20㎛) during the spring bloom period, while C. sinicus fed mostly nano-sized, and micro-sized ciliates and heterotrophic donoflagellates in summer. These results indicated biomass and prey selectivity of zooplankton was likely related to the physical and biological properties of the cold waters in the Yellow Sea.