辽东湾近海鱼卵、仔稚鱼种类组成和保护分析

2008年5、7、9、10月采用浅水Ⅰ型浮游生物水平和垂直拖网对辽东湾鱼卵、仔稚鱼种类组成开展了调查,在相同的46个站位进行了4个航次调查,每站表层水平拖网10 min,拖网速度为2.5~3.0 kn;垂直拖网由底到表,拖网速度约0.5 m/s。结果表明:2008年辽东湾近岸海域5、7、9、10月4个航次调查共捕获鱼卵7724粒、仔稚鱼229尾,32种;能鉴定到种的有29种,隶属9目、21科、28属,有两种鉴定到科,有一种未能鉴别;短吻红舌鳎Cynoglossus joyneri、鳀Engraulis japonicus、皮氏叫姑鱼Johnius belengerii、小黄鱼Larimichthys polyactis、斑鰶Konosirus punctatus、青鳞小沙丁鱼Sardinella zunasi和蓝点马鲛Scomberomorus niphonius是主要产卵群体;辽东湾北部海域、长兴岛周边海域为主要产卵区域。研究表明,与1998年5、8、9月历史调查数据相比,产卵物种数量稍有下降,但鱼卵、仔稚鱼数量下降较大;控制捕捞强度、开展人工鱼礁建设、建立种质资源保护区、规范用海生态损害赔偿标准是保护辽东湾产卵场的有效措施。

Species composition and protection of fish eggs and larvae in the coastal waters in Liaodong Bay

The species composition of fish eggs and larvae was investigated by horizontal trawling associated with vertical trawling with a zooplankton net in 46 sampling sites in coastal waters of the Liaodong Bay via 4 cruises,in which the horizontal trawling were for 10 min duration at a speed of 2.5 to 3.0 kn on the sea surface,while the ver-tical trawling were from surface to near-bottom at a speed of 0.5 m/s at each sampling station, conducted at the same 46 stations in May,July,September and October of 2008. It was found that 7724 eggs and 229 larvae of fi-shes belonging to 32 taxa were collected, in which 29 taxa were identified as species, belonging to 9 genera, 21 families and 28 orders,2 taxa were identified to only family level,and one failed to be identified. The main spaw-ning groups were Joyner's tongue-sole Cynoglossus joyneri, Japanese anchovy Engraulis japonicus, Belenger's jew-fish Johnius belengeri,drum Larimichthys polyactis, Konosirus punctatus, sardine Sardinella zunasi, and mackerel Scomberomorus niphonius,and the main spawning ground was found in northern waters and Changxing Island waters in Liaodong Bay. There was slightly less spawning species in the 2008 survey compared with the 1998 survey,espe-cially the number of eggs and larvae. The effective measures for protection of spawning grounds in Liaodong Bay are suggested including control of fishing intensity, development of artificial reefs,and establishment of germplasm re-sources protection zones,and standard of ecological damage compensation for sea.