胶州湾菲律宾蛤仔死壳分布与生态环境关系的研究

胶州湾菲律宾蛤仔栖息地带由于近年受拖耙捕生产，底质遭到频繁骚动。同时沿岸带局部水域环境污染严重，以及河口盐度突发性骤降等因素，直接影响了蛤仔的存活率。因而蛤仔死壳逐年增多。据１９９０年调查，９月份幼蛤和成蛤死壳平均密度比同年４月分别增加３．５倍和１．８倍，蛤仔资源量亦受一定损失。

A STUDY OF THE RELATION BETWEEN THE DISTRIBUTION OF DEAD SHELLS OF RUDITAPES PHILIPPINARUM AND THE ECOLOGICAL ENVIRONMENT IN JIAOZHOU BAY

Recently the number of dead clam shells (Rudiiapes philippinarum) has been increasing sharply because of the adoption of trawling in production and the change in ecological environment in Jiaozhou Bay. According to the investigations in 1990, the average density of dead clam ahells in September, when compared with that in April, is 3.5 times as large in young clams and 1.8 times as large in 1 to 4-year-old clams. The data from the relation between the distribution of dead shells and the condition of sediment reveal that serious environmenta pollution in the east coastal zone of Jiaozhou Bay is the cause of the clam's unhealthy growth and lethal mortality from toxin. In addition, the frequent torrential rains in July and August of 1990 caused a drop in sea water salinity. As a result, there was a general rise of clam mortality in the coastal zone. Data from initial analysis prove that the number of dead shells of Ruditapes philippin. arum is closely related to the trawling production and to the change in ecological environment.