健跳港上游湾区牡蛎潮间带分带格局和资源补充研究#br#

为了解牡蛎在潮间带的生态特性及资源分布情况,调查了浙江三门健跳港上游湾区牡蛎潮间带分带格局,并检验附苗器类型和地点对牡蛎资源补充的影响。结果显示:潮间带定量调查共记录到3种牡蛎,即熊本牡蛎(Crassostrea sikamea)、近江牡蛎(C.ariakensis)和香港牡蛎(C.hongkongensis),首次在浙江海域记录到香港牡蛎的自然分布。熊本牡蛎在调查的5个潮区(1.4 m、2.2 m、3.0 m、3.8m、4.6 m)均有分布,其平均密度沿增加的高程梯度呈现上升趋势,其中4.6 m潮区熊本牡蛎密度显著高于1.4 m和2.2 m潮区(P<0.05)。近江牡蛎和香港牡蛎仅分布于最底层的1.4 m和2.2 m潮区。牡蛎资源补充实验结果表明,该湾区具有很高的熊本牡蛎资源补充量,采苗地点(P<0.05)和附苗器类型(P<0.05)均显著影响牡蛎苗的密度和壳高,总体上水泥片的附苗效果要好于塑胶轮胎,上游S1点附苗效果优于下游S2点,推荐上游S1点作为熊本牡蛎附苗场。

Intertidal zonation and recruitment of oysters in the upstream of Jiantiao Bay,Sanmen County,Zhejiang Province

This study aims to explore the intertidal zonation pattern of oysters and examine the effect of breeding site and spat collector on oyster recruitment in the upstream of Jiantiao Bay,which is essential to understand the biology,ecology and resource conservation of oysters.The quantitative field observations identified Kumamoto oyster Crassostrea sikamea,Sumonie oyster C.ariakensis and Hongkong oyster C.hongkongensis by using the morphological and molecular methods.C.hongkongensis was first recorded on the coast of Zhejiang Province.Crasssostrea sikamea was present at all five tidal zones(1.4 m,2.2 m,3.0 m,3.8m,4.6 m above the standard level in Jiantao Bay hydraulic station),and its densities gradually declined along a decreasing tidal elevation gradient.The densities of C.sikamea were the highest at the 4.6 m tidal zone and were significantly greater than those at the 1.4 m and 2.2 m tidal zones(P<0.05).Crassostrea ariakensis and C.hongkongensis were only present at the deepest two tidal zones(1.4 m and 2.2 m).Results from the oyster recruitment experiments indicated that both recruitment site and spat collector significantly affected the densities and shell height of oyster spat.There were high oyster recruitment in the Jiantiao Bay.The study conlcuded that concrete tiles were better spat collector than plastic ring.In general,the upstream site(S1)should be recommended as the suitable breeding ground for C.sikamea.