| Title |
Fish Compositions and Distribution Characteristics in the Upstream and Downstream Region of Seungchon Weir |
| Authors |
박찬서 ( Chan Seo Park ) ; 최지웅 ( Ji Woong Choi ) ; 이재훈 ( Jae Hoon Lee ) ; 임병진 ( Byung Jin Lim ) ; 박종환 ( Jong Hwan Park ) ; 안광국 ( Kwang Guk An ) |
| Keywords |
Distribution; Fish community; Seungchon Weir; Weir construction |
| Abstract |
Seungchon Weir was constructed in 2010 on the downstream region of Yeongsan River watershed for four major river projects. The purpose of our study was to determine whether fish compositions and distributions differ between the upper Uw and lower regions Lw of Seungchon Weir during May December 2011 along with hydroacoustic fish surveys using Eco Sounder monitoring EsM technique. Total number of fish species sampled by conventional fish sampling at all sites was 29, and 21 and 24 species occurred in the Uw and Lw, respectively. Most dominant species was Hemiculter eigenmanni 43% in the Uw and Opsaiichthys uncirostris 21% in the Lw indicating a distinct differences of the species composition. According to hydroacoustic approach of EsM, fish density was significantly higher p<0.05 in the Lw section of 250 m than any other sections, This outcome indicates that fishes moving toward the upstream were blocked by weir construction. According to analysis of tolerance guilds, tolerant species TS were made of 88% and 79% in the Uw and Lw region, respectively, while the proportions of sensitive species were < 0.1% of the total in the both regions. Trophic guild analysis showed that the proportion of omnivore species were 58% and 40% in the Uw and Lw region, respectively, while insectivores were made of 16% and 21% in the Uw and Lw region, respectively. Both analyses of tolerance guilds and trophic guilds indicate the biological degradation fo the waterbody. Fish community structure analysis, based on species diversity, dominance, and evenness indices, showed higher community stability in the Lw region than Uw region. Exotic species of largemouth bass were largely increased in this survey 14% , compared to the past <1% , indicating a modification of fish trophic structure. |