| Title |
Potential Effect of Increased Water Temperature on Fish Habitats in Han River Watershed |
| Authors |
정남일 ( Nam Il Chung ) ; 박배경 ( Bae Kyung Park ) ; 김경현 ( Kyung Hyun Kim ) |
| Keywords |
Fish assemblage change; Han River watershed; Maximum thermal tolerance; Suitable habitat; Water temperature increase |
| Abstract |
The potential effects of increased water temperature on fish assemblages and their habitats were studied in the streams of the Han River watershed when the water temperature was supposed to increase by 1˚C, 2˚C, and 3˚C in each sampling site. The percent changes in suitable habitats for each species and in species number within a site were determined, based on the estimated maximum thermal tolerances of 51 fish species whose habitats were classified into four reaches: upstream, up-/midstream, midstream, and mid-/downstream. The maximum thermal tolerance ranged between 25.0˚C and 31.0˚C and significantly increased as the habitat reaches move from upstream to mid-/downstream. With the increases in water temperature, the average suitable habitats for all 51 species were decreased by 31% (+1˚C), 46% (+2˚C), and 60% (+3˚C). The increased water temperature, however, did not induce significant differences in the changes in suitable habitats among four reaches within each level of temperature increase. The relative frequencies of the sampling sites classified into six levels according to the percent change in the number of species in each site were significantly different among three levels of water temperature increase, with relatively greater changes in the sites where 0~20% and 61~100% of species were affected. |