영광 와탄천의 중형동물플랑크톤 군집동태

Abstract

Mesozooplankton dynamics were studied in Watan stream which flows into the Yellow Sea in Yeonggwang, Korea. Samples were collected at eight stations bimonthly during April 2006~February 2007. Mesozooplankton community was consisted of 45 taxa (8 cladocerans and 29 copepods). The abundance varied between the highest one (31~127,587 indiv. m-3) in October, and the lowest (12~233 indiv. m-3) in December. Diversity index showed to be the highest value in July (0.671) and the lowest one in August (0.368). A euryhaline species, Acartia hongi was dominant in brackish water stations (the highest abundance at 13.4℃ and 14.1 psu). In freshwater stations of the upstream, two cladoceran species of Polyphemus pediculus and Moina weismani occurred in high abundance in August. Dominant taxa of copepod were clustered to two or three groups mainly due to the difference of salinity gradients. Spatial distribution of mesozooplankton revealed to be determined by salinity gradients which were affected by opening and closing of the artificial dam in Watan stream.