제주도 우도 연안 해조류의 군락구조 및 생물량 계절변동

Abstract

Udo is located at the easternmost part of Jeju Island, Korea. This study was investigated macroalgal flora, community structure and biomass at the northern part, Jeonheul and southern part, Cheonjin of rocky shore in Udo. The collections were conducted using quadrat method on line-transect ranged from upper intertidal to 9 m depth of subtidal zone during a year. A total of 231 macroalgal species was confirmed: 26 green, 56 brown and 149 red. In the seasonal variation of macroalgal community, the dominant species based on coverage, frequency and biomass is same in both sites: Ecklonia cava during summer and autumn, Sargassum fusiform during winter, but in spring, Sargassum horneri at Cheonjin and Ecklonia cava at Jeonheul. In addition, there were represented Sargassum fusiform and Ishige okamurai in the intertidal zone and Ecklonia cava, Plocamium telfairiae, Amphiroa anceps and Sargassum spp in subtidal zone. The vertical distribution of macroalgae at Udo was characterized by Ishige okamurai, Sargassum fusiform, Corallina pilulifera and Ecklonia cava. The mean biomass during a year was similar between two sites, approximately 2400g w.weight/m2. The representative alga by mean biomass was Ecklonia cava and the value was 874.89g. The highest value of biomass was recorded at the middle intertidal zone in spring, whereas the lowest value was at the upper intertidal zone in summer. Ecological status estimated by Ecological Evaluation Categories was different from two sites: Jeonheul was 'moderate' and Cheonjin was 'good'. Although the number of cold water macroalgal species tend to be decrease, diversity index and dominant index indicate that the seaweed community structure at Udo of Jeju Island is still stable showing relatively higher macroalgal biomass and diversity than other coast of Korea.