福建中部近海鱼类生态类群的季节变化

为探究福建中部近海鱼类生态类群组成的季节变化,采用非线性多维标度(NMDS)和相似性检验(ANOSIM)方法,依据2009年冬季、2010年春季和夏季于福建中部近海3个航次的海洋综合调查资料,对该海域鱼类的种类组成和生态类群结构进行分析。结果显示,冬季出现鱼类40种,生态类群以暖水种为主,但暖温种比例为3个季节中最高(30%),且暖温种占该季鱼类总质量和总尾数比例分别为17.65%和16.96%。春季出现鱼类39种,生态类群以暖水种为主,分别占该季节鱼类总质量和总尾数的86.48%和94.52%。夏季出现鱼类61种,暖水种占绝对优势(56种),分别占该季鱼类总质量和总尾数的97.17%和99.35%。受浙闽沿岸流和台湾海峡暖流的交替影响,从冬季到夏季物种更替率逐渐升高,暖水种种类数和数量密度不断上升,并伴随着河口种消失、外海种出现。此现象与冷、暖水团交替影响这一海域时,鱼类进行相应的产卵、索饵及越冬洄游等有关。研究表明,福建中部近海鱼类生态类群和种类组成的季节变化可能由水团不断变化所导致。

Seasonal variation of ecological groups of fish in the coastal waters of central Fujian Province

In order to explore the seasonal variation of the eco-groups in the coastal waters of central Fujian Province, we conducted three comprehensive marine surveys during December 2009 and April and August 2010, and the species composition and eco-groups were discussed by using non-metric multidimensional scaling (NMDS) and analysis of similarity (ANOSIM). The results showed that a total of 40 species was identified in winter, warm-water-species were the dominate eco-groups. But the ratio of warm-temperature-species were the highest (30%) among three seasons, and accounting for 17.65% and 16.96% of the biomass and individual density respectively. There were 39 species of fish in spring, and eco-groups are still dominated by warm-water-species. The biomass and individual density of the warm-water-species accounted for 86.48% and 94.52% of the total amount respectively. In summer, fish species accounted for 61, and warm-water-species appeared in large number by 55 species, accounting for 97.17% and 99.35% of the biomass and individual density respectively. Affected by Zhejiang-Fujian coastal water and Taiwan Strait warm current water alternately, species turnover rate and the number and density of warm water species were increased gradually, and accompanied by the estuarine species replaced by coastal species from winter to summer. The phenomenon was related to fish spawning, feeding and wintering migration, when Zhejiang-Fujian coastal water and Taiwan Strait warm current water occupied this area. It is concluded that the seasonal variation of eco-groups and species compositions in the coastal waters of central Fujian Province may be affected by the changes of water masses.