항만적 접근 관점에서 본 중형동물플랑크톤 군집의 연안역 비교

Abstract

Present study is designed to get the plankton data through port baseline study to support the database system for risk assessment based on developing 󰡒port environmental risk assessment technology󰡓. Mesozooplankton sampling were planned to collect seasonally from four major ports such as Incheon, Gwangyang, Pusan and Ulsan ports. But, data collected in winter and spring are described in the present study. Mesozooplankton in Pusan and Ulsan ports were sampled aboard the R.V. 󰡒Jangmok󰡓, and that in Incheon and Gwangyang ports were collected using the ships of opportunity. Stations for analysis of the spatial distribution in mesozooplankton and its related environmental factors were selected considering characteristics of the inner and outer ports. Vertical profiles of temperature and salinity were obtained using a SBE 911plus CTD and the data were binned into 1 m depth. Mesozooplankton were sampled with a standard type net (200㎛ in mesh size, 0.6m in diameter) by vertical hauls from 5m above the bottom to the surface at a speed of 0.5~1 m s-1. Surveys were made in the daytime and always at the same tidal period, starting at high tide from the innermost station. In winter, most of the mesozooplankton community was composed of immature calanoid copepods in Pusan port, whereas immature cyclpoid copepods in Ulsan port. Mesozooplankton community in Gwangyang port was dominated by N. scintillans, while Acartia hongi and immature calanoids were dominant in the mesozooplankton community in Incheon port. Interestingly, A. hongi that showed high abundance and distributed southwestern coast waters of Korea, occurred with the percentage of 4.3% in Pusan port. In spring, the species did not occur in Ulsan port but in Gwangyang port with relatively higher percentage of 11.4% compared to winter. The species dominated commonly in the Incheon port in winter and spring. There are several possible hypotheses in relation to the intermittent occurren