ZOOPLANKTON COMMUNITY STRUCTURE IN THE SOUTH YELLOW SEA IN WINTER AND INDICATION OF THE YELLOW SEA WARM CURRENT

Zooplankton community structure in winter was studied in the South Yellow Sea during two cruises in December 2009 and January 2010.The indication of warm water zooplankton to the Yellow Sea Warm Current(YSWC)was also analyzed based on these data.The zooplankton community was dominated by temperate and warm-temperate species in the South Yellow Sea in winter,of which Calanus sinicus,Aidanosagitta crassa,and Themisto gracilipes were overwhelming species.In December 2009,most warm water species were found in the southeast part of survey area where YSWC intruding.The eastern part of the survey area presented hydrographic characteristics of the remained Yellow Sea Cold Water:low temperature,high salinity and high nutrient contents.In January 2010,more warm water species were found between 35°N and 36°N.The locations of the tropical species Paracandacia truncata and Clausocalanus furcatus were consistent with the path of the YSWC.The distribution of the amount of Euchaeta rimana presented the northward trend in comparison with that in December,2009.Principal Component Analysis indicated that occurring of warm species was related to seawater temperature.The influence of YSWC on zooplankton community structure was small during the study period.