人工鱼礁区不同底质对底栖游泳生物群落特征的影响

为探究人工鱼礁投放后的不同底质对底栖游泳生物群落结构特征的影响，实验以海区中央投放的构件礁划分半径为20、400和600 m 3个样带，采用地笼与摄像相结合的方法，分别于2017年6月和8月、2018年6月 (2次)、2019年6月和7月在小竹山岛人工鱼礁区进行了6个航次的调查。应用相对重要性指数 (IRI)、主坐标分析 (PCoA)和单因素方差分析等分析群落时空组成变化，利用广义加性模型 (GAM)研究环境因子对单位捕捞努力量 (CPUE)和多样性指数的影响。IRI和PCoA测定结果显示，地笼主要捕获日本蟳、海燕、大泷六线鱼、许氏平鲥及其他梭形鱼类；摄像主要捕获海燕等棘皮类、葛氏长臂虾、纹缟虾虎鱼、六丝钝尾虾虎鱼、钟馗虾虎鱼及矛尾刺虾虎鱼。单因素方差分析显示，两种采样方法在200和400 m样带的CPUE均较高，与600 m样带有显著差异，但年份间无显著差异。GAM模型显示，CPUE随投礁年份和底质类型的复杂度增加而增加，与构件礁及石块礁底质呈正相关，且受盐度及温度影响。多样性指数在样带、年际间无显著差异，GAM模型显示，其在地笼渔获物的多样性指数显著高于摄像，并受盐度、透明度影响，但与底质类型无关。本研究揭示了不同底质对底栖游泳生物的影响，证明了地笼与摄像结合调查方法的互补性，为多种鱼礁底质的管理提供参考依据。

Effects of different substrate types on community characteristics of benthic swimming organisms in the artificial reef area

In order to explore the impact of different substrate types after the deployment of artificial reefs on the community structure characteristics of benthic swimming species, six cruises of field surveys were conducted in the artificial reef area located in the Xiaozhushan Island. The survey area was divided into three transects with a radius of 200 m, 400 m, and 600 m based on the artificial reef modules deployed in the center of the sea area. Trap and visual census methods were combined to sample benthic swimming organisms in June, August 2017, June 2018 (twice), and June, July 2019. Relative importance index (IRI), principal coordinate analysis (PCoA) and one-way analysis of variance (ANOVA) were utilized to explore the variance of spatial-temporal constitution of the community, and General additive model (GAM) was utilized analyze the effects of environmental factors to catch per unit effort (CPUE) and biodiversity index of the community. The results showed that two sampling methods totally obtained 47 species in 5 categories, including 38 species from trap, 28 species from visual census and 19 species in common. IRI and PCoA indicated that Charybdis japonica, Asterina pectinifera, Hexagrammos otakii, Sebastes schlegelii, and other fusiform fish were mainly captured by trap; Echinodermata such as A. pectinifera, Palaemon graviera, Tridentiger trigonocephalus, Amblychaeturichthys hexanema, Triaenopogon barbatus and Chaeturichthys stigmatias were mainly captured by visual census. One-way ANOVA of both sampling methods indicated that the CPUE of 200 m and 400 m transects was significantly higher than 600 m transect, but there was no significant difference between years. GAM showed CPUE increased with the rising complexity of substrate types and duration of the deployment of artificial reefs, was positively correlated with substrates of artificial reef and rock, and was affected by salinity and temperature. In addition, GAM showed that biodiversity index of trap was significantly higher than visual census, and it was influenced by salinity and transparency. But there was no connection with substate types. This study revealed the effects of different substrate types to benthic swimming organisms, proved the complementary of the combination of trap and visual census, and provided a reference for the management of reef substrate.