瓯江鱼类资源调查及保护对策

瓯江是浙江省第二大江，鱼类资源丰富，然而至1972年调查以来，尚未有全面的鱼类资源调查研究。对瓯江干流从上游查田镇至下游海口镇的5个采样点进行了较全面的鱼类调查，共采集鱼类标本1 246尾，隶属于5目14科46属60种。相比1972年调查结果，有34种未采集到，其中包括列入中国濒危动物数据库的4种：中华鲟、鲥、香鱼、花鳗鲡；本次调查结果较1972年调查新增19种，其中外来鱼类2种：莫桑比克罗非鱼、大口黑鲈。在对5个采样点的鱼类组成、群落相似度、优势种组成、生物多样性指数等进行分析后，发现瓯江上游鱼类种类以流水性鱼类为主，且生物多样性较高；中下游鱼类种类组成以静水性鱼类为主，且生物多样性较低。本次调查的每日单船渔获量为45 kg/（船·d），仅为1972年的25%，鱼类资源衰退严重。最后，对鱼类资源下降的原因进行了分析，并提出了保护对策

INVESTIGATION OF FISH RESOURCES IN THE OUJIANG RIVER AND ITS PROTECTION STRATEGY

The Oujiang River is the second biggest river in Zhejiang Province and its fish resources are very rich.But comprehensive survey of fish resources has not been made since 1972.We made an investigation of fish resources of the Oujiang River from its upstream (Chatian Town) to the downstream (Haikou Town) in 2010.1 246 fish specimens were collected,which belonged to 5 orders,14 families,46 genera and 60 species.Compared to 1972 survey results,34 species were not collected, including 4 species in the database of Chinese endangered animals:〖WTBX〗 Acipenser sinensis〖WTBZ〗, Macrura reevesii, Plecoglossus altivelis and Anguilla marmorata; and 20 species were new record, including 2 exotic fish species: Tilapia mossambica and Micropterus salmoides. We analyzed community similarity, dominant species composition, biological diversity of five sample sites,and found that the upstream fish community had higher biodiversity than the downstream.CPUE of this investigation was 45 kg/boat/day,only 25% as in 1972,which indicated that the fish resources were decline badly. In this paper we analyzed the reasons and proposed the protection measures