Pollution situation in the Laizhou Bay and its effects on fishery resources

Abstract

According to the results of pollution investigations in the Laizhou Bay in April, July and October 1998, the effects of pollutants entering sea on the pollution of Laizhou Bay, distribution characteristics and flux of pollutants were discussed in this paper. The results indicated that the main pollutants were distributed in the western and southwestern Laizhou Bay. The analysis results of relationship between environmental factors and fishery resources illustrated that pollution factors had effects on the relative quantity variance of larvae of shrimp. In recent years (from 1990 to 1998), the correlation between Chemical Oxygen Demand (COD) and relative quantity of larvae of shrimp was more obvious (γ=-0.565 8).It is worth to point out that from 1994 to 1998 the negative correlation between relative quantity of shrimp larvae and COD,IP was significant (γ=-0.863 3 and -0.792 8 respectively). Because the impacts of pollution entered the sea with runoff on marine environment became serious, great variations of the structure, composition and quantity of fishery resources had been taken place. The serious pollution in estuaries not only destroyed fishery resources, but also destroyed the spawning grounds. The distribution scope of fish eggs in the neighboring area of Xiaoqing River was reduced and its kind and amount also decreased. The distribution area of fish larvae moved to Yellow River Mouth and Diaokou region from the adjacent area of Xiaoqing River and the larvae had the behavior evading the pollution of this area. Xiaoqing River is one of the main pollution sources in the Laizhou Bay, its destruction to fishery resources is both typical and universal and represent the harm of pollution on fishery resources in the Bohai Sea.