The status of fishery resources of Lake Chaohu and its response to eutrophication

Front 2002-2004, investigations on fish communities were carried out in Lake Chaohu. According to historic data, the dynamic variation of fishery resources of Lake Chaohu was analyzed in recent 50 years. There are 54 fish species found, belong to 8 orders, 16 families, of which the fishes of Cyprinidae were 35 species and accounted for 64.8% and migration fishes were very scaring. It indicated that the tendency of small-sized fisheries and the lower yield fish were obvious. Due to water engineering were built in 1960s, most potsmodromous fishes decreased greatly by 40% of total fish yield before the built of dams to less than 10% in present study period. Another important factor is overfishing. 9 folds of fishing boats and 5 folds of fishermen were found ill 2002, which brought much fishing pressure in Lake Chaohu. Furthermore, eutrophication and lack of aquatic macrophytes were affected the communities of dominanted fishes in Lake Chaohu. Based on analyses of composition of fish catchments and relationship between fish yield and eutrophication, eutrophication control and sustainable development of fisheries of Lake Chaohu are put forward. fit order to develop sustainable fisheries in Lake Chaohu, both biomanipulation and non-biomanipulation should be Suggested in future