渤海莱州湾渔业资源增殖的敌害生物及其对增殖种类的危害

根据近岸捕食鱼类胃含物分析及渤海生物资源大面积定点拖网调查 ,研究了渤海莱州湾渔业资源增殖的敌害生物种类、分布及其对增殖种类的危害 .结果表明 ,鲈鱼幼鱼、黄姑幼鱼、绵鱼尉、虾虎鱼类是捕食渤海对虾、梭鱼等增殖种类幼体的主要敌害生物 ,危害主要发生在近岸 ,其中鲈鱼危害较为严重 ,主要危害期为 7月 ,被捕食的幼对虾长度以 3～ 7cm为主 .鉴于敌害生物大量捕食增殖种类主要发生在近岸和两者密集分布区的重叠处 ,在增殖放流区选择上 ,对敌害生物采取“回避”策略是保护增殖放流种类的可行措施 .

Predator species of fishery resources enhancement and their predation on enhancement species in Laizhou Bay of Bohai Sea.

Based on the analysis of stomach contents of nearshore predator species and on the trawl survey of marine resources covering large area in the Bohai Sea,the composition and distribution of the predator species, and their harm to the enhancement species of fishery resources in the Laizhou Bay of Bohai Sea are studied. The results indicate that the juveniles of perch( Lateolabrax japonicus),Nibea albiflora, Enchelyopus elongatus and Chaeturichys spp.are the main predators of the juveniles of penaeid shrimp and Liza haematochelia, etc.,which are the species of enhancement in Bohai Sea. Predation occurs mainly in nearshore waters. Among the predators, perch is the most important one whose predation takes place mostly in July,and the length of juvenile penaeid shrimp consumed ranges from 3 to 7 cm.Due to the fact that predation on the enhancement species takes place mainly in nearshore and waters where both predator and enhancement species are densely distributed and overlapped, the strategy of avoidance to the predators will be a feasible approach of protecting released juveniles of enhancement species in the selection of enhancement release regions.