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为了评估鱼类对长江口栖息地的选择偏好,选取长江口春季的优势种棘头梅童鱼幼鱼为模式物种,从19个水文、水质因子及生物因素指标中,筛选出狭额绒螯蟹丰度、盐度、底质类型和水深4个因子作为棘头梅童鱼栖息地指示因子,建立栖息地适合曲线,并计算了栖息地适宜度指数(HSI).结果表明:长江口北支水域棘头梅童鱼幼鱼HSI普遍较高,基本在0.5以上,而南支水域普遍较低,基本上在0.2以下,表明长江口北支为棘头梅童鱼幼鱼的主要索饵场,同时发现,其幼鱼的最适生长水域为盐度大于14、底质平均粒径在29μm以下、水深2~5 m的水域,与HSI的空间分布一致.生物因子可较好地表征棘头梅童鱼幼鱼对水文、水质等因素的响应;化学需氧量、铵氮、总磷和挥发性酚与棘头梅童鱼幼鱼丰度不具有显著相关性,亚硝酸盐氮、硝酸盐氮和总氮与其丰度具有显著正相关性,说明调查水域内水质的富营养化尚未对棘头梅童鱼栖息地造成破坏;而铜离子和镉离子浓度与其丰度具有极显著的负相关性,表明重金属污染已经对棘头梅童鱼幼鱼的生长和分布造成了一定的危害,推测重金属污染对长江口水域的鱼类栖息地分布具有限制性影响.
In order to assess the preference of fish for the habitat of the Yangtze River Estuary, the dominant species of Acanthocephala sibirica in the Yangtze River estuary were selected as model species. Thirteen indicators of hydrology, water quality and biological factors Crab abundance, salinity, sediment type and water depth were used as indicator of habitat habitat, and the habitat suitability curve was established and habitat suitability index (HSI) was calculated.The results showed that: The HSI of the juvenile Acipenser sinensis in the branch waters was generally high, mostly above 0.5, whereas that in the South Branch was generally low, basically below 0.2, indicating that the northern branch of the Yangtze Estuary was the major bait for juvenile Acipenser sinensis Field and at the same time found that the optimum growth water area for juvenile fish is the spatial distribution of HSI consistent with the spatial distribution of salinity greater than 14 and sediment average diameter less than 29μm and water depth of 2 to 5 m.The biological factors can be well characterized There was no significant correlation between chemical oxygen demand, ammonium nitrogen, total phosphorus and volatile phenol and the abundance of juvenile Acipenser schrencki juveniles. Nitrite nitrogen , Nitrate nitrogen and total nitrogen have a significant positive correlation with their abundance, indicating investigation of water The eutrophication of the water quality has not yet caused any damage to the habitat of the primate snakehead. However, the concentrations of copper and cadmium have a very significant negative correlation with their abundance, indicating that heavy metal pollution has had a significant effect on the growth of juvenile And distribution caused some harm, suggesting that heavy metal pollution has a restrictive impact on the distribution of fish habitats in the Yangtze River Estuary waters.