Seasonal Variations in the Species Composition of Fishes Caught by Gill Net in the Coastal Waters off Gujora and Mangchi on Geoje, Gyeongnam, Korea

摘要

The monthly variation in species composition of fishes in the Gujora and Mangchi coastal waters in Geoje, Korea, was investigated between June 2018 and May 2019 through monthly fish collections using a gill net. A total of 46 species, numbering 410 individuals weighing a total of 96,645.0 g, were collected during the study period. The dominant species in terms of numbers were Chelidonichthys spinosus, Stephanolepis cirrhifer, Ditrema temmincki, Sillagojaponica, Sebastes inermis, and Paraplagusia japonica. The number and biomass of fishes peaked in July. The peak in species diversity indices occurred in September. The cluster analysis revealed that there were four groups of fishes depending on the season. In addition, subtropical fishes were recordedin the study area, indicating the gradual subtropicalization of the coast of Geoje. Furthermore, the need to understand the changes in marine ecosystems owing to subtropicalization through continuous monitoring is emphasized.