不同网具在人工鱼礁水平方向上诱集效果的比较

摘要

为了解东海典型软相泥地生境鱼礁投放后在水平梯度上的影响能力,于2014年8月在嵊泗人工鱼礁区采用等间距设点的方法,对不同网具(刺网、地笼网、拖网)在评价人工鱼礁区鱼类和大型无脊椎动物组成方面的应用效果进行了初步探讨.结果表明,刺网渔获组成以鱼类为主,占刺网总渔获种类的51.1％;拖网主要为节肢类,其次是鱼类,分别占拖网总渔获种类的41％和37.7％;地笼网的渔获种类分布则较为均衡.比较不同采样方法在鱼礁区水平方向上多样性的表征能力,拖网优于刺网和地笼网,3种网具组合的采样方式优于单种网具或任意两种网具相互组合.自人工鱼礁核心区向外,各站点生物资源量、多样性等指标大致呈逐渐减少的趋势.从上述指标的空间差异来看,三横山鱼礁区的有效辐射距离约为200 m,而东库山鱼礁区辐射距离为200～300 m.研究结论认为,相对于单一采样方法,组合刺网、地笼网和改进型底拖网的综合采样方式可以获得更完整的现场信息,从而更好地揭示人工鱼礁投放后水平方向的资源分布和群落结构状况.%Fishes and macro-invertebrates were sampled at two artificial reef sites in August of 2014 using sampling tools (gillnet,cage,trawl) to find out the horizontal boundaries of fish aggregating effects by deployed artificial reefs (AR) as well as sampling efficiency of the applied sampling tools.Fish are the most abundant species for tra mmel nets catch.It took 51.1％ of the total gillnets catch;trawls was the most efficient tool for collection of arthropod,followed by fish,accounting 41％ and 37.7％ respectively of the total catch.Catch of cages did not show any significant difference on species abundance or biomass between different species types along the selected transects.Trawls acted as a better tool on species diversity investigation than trammel nets and cages,while the combination those three tools can draw a most complete picture for local species composition status.For the abundance,biomass and diversity indices,both trammel nets and trawls had the highest density and diversity at core area of sampling AR sites,decreasing slowly along the selected four transects.Based on that,we extracted a distance of 200 m as the effective radiation range of Sanheng AR area while 200-300 m of Dongku AR area.It is concluded firstly that different sampling tools have different advantages on fish and macro-invertebrate evaluation,thus the combination of different tools is needed to reveal the most complete and accurate status of AR aggregating effects.Secondly,the effective range of fish aggregating function by deployed AR could be restricted in a very narrow area less than 1000 m and it is 200 m for this study.