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根据2004年8月、11月和2005年2月(Ⅰ年度),2005年8月、11月和2006年2月、5月(Ⅱ年度),2007年8月、11月和2008年2月、5月(Ⅲ年度)共3个水文年对长江口近岸水域(121°32.08′～122°11.65′E,31°19.58′～31°38′N)15个取样站点11个航次的底拖网调查样品,对该水域的鱼类种类组成、生物量、丰度、优势种、生物多样性的时间和空间动态变化进行了分析.结果表明:调查水域共出现鱼类13目24科39属42种,鲈形目种类(18种)最多,其次为鲱形目(5种)和鲤形目(4种),种类组成有明显的季节变化,夏季种类数最多,冬季最少;生物量和丰度年度和季节变化明显,平均值分别为8.10 g(100 m2)-1和1.25 ind(100 m2)-1,鱼类生物量和丰度均呈显著下降趋势(Ⅲ年度<Ⅱ年度<Ⅰ年度),季节变化趋势为夏季>春季>秋季>冬季;生物多样性指数以夏季最高,春季最低,且有下降的趋势;优势种的种类与优势度季节和年度间有较大的变化,造成这种趋势的主要原因可能是与棘头梅童鱼(Collichthys lucidus)和凤鲚(Coilia mystus)的繁殖和索饵洄游有关.
According to August 2004, November and February 2005 (Year I), August, November 2005 and February 2006, May 2006 (Year II), August 2007, November 2007 and February 2008 In May, there were 3 hydrological years in total. At the end of 11 voyages of 15 sampling sites in the coastal waters of Changjiang Estuary (121 ° 32.08 ’~ 122 ° 11.65’E, 31 ° 19.58’ ~ 31 ° 38’N) The trawl samples were used to analyze the spatial and temporal dynamics of fish species composition, biomass, abundance, dominant species and biodiversity in this area. The results showed that there were 13 fish, 42 species, Percian species (18 species) most, followed by the herring (5 species) and Cypriniformes (4 species), the species composition of the obvious seasonal changes, the largest number in summer and winter minimum; biomass and The annual and seasonal variations of abundance were significant with the average values of 8.10 g (100 m2) -1 and 1.25 ind (100 m2) -1, respectively. The biomass and abundance of fish showed a significant decreasing trend (Ⅲ year <Ⅱ year <Ⅰ Year), the seasonal variation trend was summer> spring> autumn> winter; the biodiversity index was the highest in summer, the lowest in spring, and there was a downward trend; the species and dominance of dominant species were larger in season and year The main reason for this trend may be related to the breeding and feed migration of Collichthys lucidus and Coilia mystus.