中国对虾放流群体在象山港中的移动和分布

浙江沿海没有中国对虾的自然分布。七十年代初引种南移至池塘获得成功。把中国对虾的南移从人工控制下的有限水体中向自然海域扩大,即进行人工放流与移植,是提高近海生产力的一个好途径。这对改变生态结构也有积极意义。了解、掌握放流移植虾群在港内的移动、分布、集群与出港规律是本项研究的重要内容。研究表明,移植虾群的移动和分布规律既显示出与它的发源地黄渤海相似的共性,又由于港域独特的地理条件和生态环境显示出自身的地理群特性。

THE MOVEMENT AND DISTRIBUTION OF RELEASED PENAEUS ORIENTALIS IN XIANGSHAN BAY

The movement and distribution of Pegasus orientalis, which werereleased in Xiangshan Bay of Zhejiang province, reside in both the same chara-cteristics as in their original place, the Huanghai sea and Bohai sea, and specia-lities due to different geographical topography and ecosystematic environment.First, the released shrimp migrate from near shore water to off shore water,with only a few of them moving irregularly. Secondly, all of them migrate to-wards the bay. There are three periods for these inhabiting ones, rig, seeking forfood in shallow water of near shore, growing in off shore water and flowing outof the bay. Most of them move in the neighbourhoodof 10 m isobath line whenonce they flow out, with a majority of them alongside northern coast. The shrimpoutflow when tide ebbs and few of them come back again. This situation becomeworse at the time of big tide. The movement and distribution are affected by anyof or a combination of following factors, such as growth and density of shrimp,water temperature, baits, topography, wind and tide etc; and the most importantfactor is shrimp growth. Torrential ebb tide and its non-strong circulation acce-lelate the outflow, with strong tropical typhoon possibly incurring shrimp out-flow.