부유토사가 담수 어류 3종 (붕어, 잉어, 송사리)의 초기 생활사에 미치는 영향

Abstract

To assess the adverse effects of suspended solids on fishes, the hatching rate of embryo, and survival and growth of larvae were measured with common fish species of river such as crusian carp (Carassius auratus), common carp (Cyprinus carpio) and medaka (Oryzias latipes). Bioassay on hatching rate of embryo was conducted with a range of turbidity as 10 levels from 0.2 to 8,080 NTU. Another bioassay on 4-day larval survival and 21-day larval growth were also conducted with a range of turbidity as 8 levels from 0.1 to 8,260 NTU, and 6 levels from 0.7 to 2,030 NTU, respectively. The hatching rate of C. auratus was not significantly different from that of control at turbidity below 4,040 NTU, whereas it decreased when turbidity was 8,080 NTU (p.0.05). The hatching rate of C. carpio was not affected by concentration of suspended solids. For O. latipes, the hatching rate significantly decreased from 254 NTU (p.0.001) and it was zero when turbidity was 8,080 NTU. The 4-day survival of larvae of all 3 species was not affected by turbidity, while the larval growth of all 3 species was significantly affected. The turbidity effect on the growth of C. auratus and C. carpio was observed from 7 days after the exposure at turbidity level of 145, 143 NTU, respectively. The turbidity effect on the growth of O. latipes was observed from 14 days after the exposure at turbidity level of 254 NTU. The results of this study will provide the basic information for the derivation of water quality criteria on suspended solids for the protection of aquatic ecosystem and the quantitative ecological risk assessment of freshwater environment.