Journal of Environmental Biology

Ecosystem structure and trophic level to the oceanographic
conditions around the waters of Jeju Island

Young Min Choi^*1, Joon Taek Yoo², Jung Hwa Choi¹, Kwang Ho Choi¹, Jin Koo Kim³, Yeong Seup Kim⁴ and Jong Bin Kim⁴

¹Fisheries Resources Research Team, National Fisheries Research and Development Institute (NFRDI), 408-1,
Sirang-ri, Gijang-eup, Gijang-gun, Busan 619-705, Rep. of Korea
²Jeju Fisheries Research Institute NFRDI, 1928 Oedo2-dong, Jeju 690-192, Jeju province, Rep. of Korea
³Department of Marine Biology, Pukyong National University 599-1, Daeyeon 3-Dong, Nam-Gu, Busan, Rep. of Korea
⁴West Sea Fisheries Research Institute, NFRDI, 707, Ulwang-dong, Jung-gu,Incheon 400-420, Rep. of Korea

(Received: February 22, 2007; Revised received: November 01, 2007; Accepted: November 27, 2007)

Abstract: The water around Jeju Island was characterized by the Tsushima warm current (TWC) being high temperature and salinity, and the Yellow sea cold bottom water (YSCBW) being low temperature and salinity. We investigated the diversity indices, community structures and trophic level of fish species collected by trawl net in the waters around Jeju Island during April 2004 – August 2005. We also presented ecosystem structure estimated by combination of trophic level and the oceanographic condition. There were totally distributed 301 species in the survey area during April 2004 – August 2005, regionally 151-229 species in TWC and 75-154 in YSCBW. Shannon’s diversity indices (H’) of TWC were 2.95-3.39, being higher than those of YSCBW (2.11-2.40), and species richness (R) of TWC were 10.93-18.33, being also higher than those of YSCBW (6.96-12.48), except the values of October 2004. A total of 7,429 individuals of 98 species was seasonally examined for their dietary composition in the survey area during 2004-2005. Of which, 3,682 individuals were observed with prey organisms. Standardized diet composition and trophic level estimates were calculated for predators in the survey area being influenced by TWC and YSCBW. Trophic level values were diverged with range from 3.23 of the small pelagic to 4.39 of the goose fish, depending on the taxonomic group. The analysis of trophic level values showed that ecosystem structure was different between TWC and YSCBW during April 2004 – August 2005.

Key words: Ecosystem, Diversity, Trophic level

PDF of full length paper is available with author (ymchoi@nfrdi.re.kr)

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