수중영상자료를 이용한 해역의 생물 서식처 지도 작성

Abstract

The coastal zone of Uljin is composed of various types of habitat from rock to mud and shallow to deep. The inshore area shallower than 30 m is mostly composed of sand and rock, whereas sandy-mud bottom is the major component of the offshore area between 30-60 m of depth. During the summer of 2004 and 2005, we chose a total 60 subtidal sites within the depth range of 5-60 m along 10 km of the coastline and investigated the composition and configuration of subtidal benthic habitats using underwater video cameras such as still digital camera, boat towed pan/tilt camera, and ROV. In addition, we also documented the composition and abundance of benthic organisms in each habitat type. From the K-mean clustering algorithm based on Euclidean distances using two physical factors such as depth and sediment type recorded at the 60 sites, a total 4 types of habitats were recognized; shallow rocky bottom (SRB) between 7-25 m of depth, shallow sandy bottom (SSB) between 8-30 m of depth, deep rocky bottom (DRB) between 25-47 m of depth, and deep sandy-mud bottom (DMB) between 35-52 m of depth. The composition and abundance of benthic organisms were apparently different between the 4 types of habitat. In SRB, dominant species were the seaweeds, Undaria pinnatifida, Sargassum horneri, Dictyota dichotoma and Phyllospadix japonica, and sessile and semi-mobile animals, polychaetes Hydroides ezoensis and Spriobranchus tetracer, and echinoderm Hemisentrotus pulcherrimus. In SSB, dominant species were semi-mobile polychaetes Spiophane bombyx, Scoletoma lingifolia and Magelona haponica. In DRB, dominant species were the seaweeds, Agarum cribrosum, Corallina pilulifera and Carpopeltis angusta, and sessile animals Metrdium senile. In DMB, dominant species were echinoderms Ophiura spp. These results indicated that the composition and configuration of habitat were highly variable within such a small scale.