温州南部沿岸海域鱼类群落特征及其与环境因子的关系

根据2015年春季(5月)和秋季(9月)温州南部沿岸海域渔业资源调查数据,利用物种多样性指数、多元分析及其典范对应分析等方法,对该海域鱼类种类组成、多样性和群落与环境因子间的关系进行了分析。结果表明:温州南部沿岸海域共鉴定鱼类47种,隶属于9目27科41属,主要以暖水性和暖温性为主,鲈形目(Perciformes)种类最多,共26种;其次为鲱形目(Clupeiformes),共6种;再次为形目(Tetraodontiformes),共4种。春季,优势种依次为日本鳀(Engraulis japonicas)、镰鲳(Pampus echinogaster)、六丝矛尾虾虎鱼(Amblychaeturichthys hexanema)和棘头梅童鱼(Collichthys lucidus),其渔获量占总渔获量的49.3%;秋季,优势种为龙头鱼(Harpodon nehereus)、棘头梅童鱼和六指马鲅(Polynemus sextarius),占总渔获量的50.8%。日本鳀、蓝圆鲹(Decapterus maruadsi)、刺鲳(Psenopsis anomala)、龙头鱼、鳓(Ilisha elongata)和六指马鲅等是各季节各站位组的典型种及造成不同站位组间群落差异的主要分歧种。此外,组内的典型种一定程度上是组间的分歧种和群落的优势种。经Pearson分析,Margalef种类丰富度指数(D)和Shannon-Wiener多样性指数(H')与溶解氧呈极显著正相关,而与盐度和温度均呈显著正相关。通过典范对应分析(CCA)得出,影响鱼类群落的主要环境因子为酸碱度p H、水深和盐度。

Fish community structure and its relationships with environmental factors in the southern inshore waters of Wenzhou

The southern coastal waters of Wenzhou is in the mid to southern parts of the East China Sea. This area is influenced by the high temperature and high salinity conditions of the Taiwan Warm Current, the low salinity of the Zhejiang Coastal Current, and the southern coastal upwelling. These waters are rich in nutrients and baitfish and are highly diverse with fish species. The area is a typical ecological region of the East China Sea shelf. Cluster analysis, non-metric multidimensional scaling, and a diversity index was used to analyze the patterns of commu-nity composition, diversity, and community structure based on data from two fishery resources investigations conducted in May (spring) and September (autumn) 2015 in the area. The results identified 47 species in the southern coastal waters of Wenzhou, which belonged to 41 genera, 27 families, nine orders, and two classes. Warmwater and warm temperate species were dominant, and Perciformes were the most abundant, with 26 species, followed by Clupeiformes, with six species. The third most frequent group was Tetraodontiformes, with four spe-cies. The dominant species in spring were Engraulis japonicas,Pampus echinogaster, Amblychaeturichthys hex-anema, and Collichthys lucidus, accounting for 49.3% of the total catch. The dominant species in autumn were Harpodon nehereus,Collichthys lucidus, and Polynemus sextarius, accounting for 50.8% of total catch.Engraulis japonicas, Decapterus maruadsi, Psenopsis anomala, Harpodon nehereus, Ilisha elongate, and Polynemus sex-tariuswere typically found at all stations in both seasons, and they were the major divergent species causing community differences among stations. Pearson's correlation analysis indicated that the richness index (D) and the Shannon–Wiener diversity index (H') were positively correlated with dissolved oxygen, salinity, and temperature. A canonical correspondence analysis suggested that the main environmental factors affecting the spatial patterns of fish assemblages were pH, depth, and salinity. pH represents the sum of some of the chemical properties in wa-ter and is the result of interactions among factors. pH can be affected by salinity and temperature. The canonical correspondence analysis results showed a division in the fish community in spring, which was likely due to influx of the high temperature and high salinity water in the Taiwan Warm Current. This current forms an obvious salin-ity gradient in the local coastal strip, which further affected the division of the spring fish community. The Taiwan Warm Current retreated in autumn, and the lower temperature and lower salinity of the Zhejiang and Fujian Coastal Currents gradually carried a large amount of silt into the study area. Therefore, whether temperature, sa-linity, and suspended particles affected the fish community structure requires further investigation.