莱州湾污染及其对渔业资源的影响

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

根据 1998年 4、7、10月对莱州湾污染调查结果 ,讨论了入海污染物对莱州湾的污染影响、分布特征及其入海通量。结果表明 ,莱州湾主要污染物分布在西部和西南部。污染物入海通量估算结果 ,小清河是莱州湾污染的主要污染源之一。对渔业资源影响关系表明 ,环境因子对幼对虾相对数量变化均有一定的影响 ,1990～ 1998年COD与幼对虾相对数量相关性相对较明显 (γ =- 0 .5 6 5 8) ,无机磷和无机氮与幼对虾数量相关性不明显。但从不同时间段看 ,1990～ 1993年只有无机氮与幼对虾数量相关性明显 ,呈正相关关系 ,而 1994～ 1998年COD、无机磷与幼对虾相对数量却呈显著负相关 (γ =- 0 .86 33,γ =- 0 .792 8)。说明近年来COD、无机磷对莱州湾幼对虾相对数量的变动构成一定的负面影响。由于陆源性污染对海域环境影响加剧 ,使得渔业资源、结构、组成和数量发生了很大的变化 ,河口污染的加剧 ,不仅破坏了渔业资源 ,更重要的是破坏了产卵场。鱼卵的种类和数量在小清河附近海域的分布范围也在缩小 ,仔稚鱼分布数量 ,已由小清河附近海域北移至黄河口至刁口一带 ,仔稚鱼有回避该区污染的现象。在莱州湾中 ,小清河为主要污染源之一 ,其对渔业资源的破坏 ,即有代表性 ,又有普遍性 。

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.