杭州湾北部海域渔业资源群落结构的季节变化特征

    Seasonal changes in the community structure of fishery resources in northern Hangzhou Bay

    • 摘要:
      目的 进一步了解杭州湾北部海域的渔业资源种类组成、资源密度、优势种和多样性等群落结构特征。
      方法 根据2023年8月(夏季)、2023年11月(秋季)、2024年1月(冬季)和2024年5月(春季)的拖网调查数据,运用相对重要性指数(IRI)、聚类分析(Cluster)和非度量多尺度分析(nMDS)对该海域渔业资源群落结构进行分析。
      结果 1)共调查渔业资源种类35种,季节排序为秋季(24种)>夏季(21种)>春季(20种)>冬季(13种);除冬季外,其他3个季节种类组成均以鱼类、虾类、蟹类为主;4个季节鱼类种类数均占绝对优势。2)杭州湾北部水域渔业资源密度呈季节性变动,尾数资源密度排序为夏季(627 591.20尾/km2)>春季(280 652.33尾/km2)>秋季(277 154.35尾/km2)>冬季(58 831.26尾/km2),重量资源密度排序为夏季(1 039.01 kg/km2)>春季(493.74 kg/km2)>秋季(211.32 kg/km2)>冬季(129.78 kg/km2)。3)生态优势度研究结果表明,仅安氏白虾(Palaemon annandalei)为4个季节共有优势种,主要渔业种类季节更替明显。夏季有4种优势种安氏白虾、凤鲚(Coilia mystus)、棘头梅童鱼(Collichthys lucidus)和龙头鱼(Harpadon nehereu),渔获量占比为69.26%;秋季有2种优势种安氏白虾和葛氏长臂虾(Palaemon gravieri),渔获量占比为61.65%;冬季有3种优势种安氏白虾、刀鲚(Coilia nasus)和葛氏长臂虾,渔获量占比为67.74%;春季有4种优势种安氏白虾、凤鲚、葛氏长臂虾和鮸(Miichthys miiuy),渔获量占比为81.85%。4)从Margalef丰富度指数(D)、Shannon-Wiener多样性指数(H')、Pielou均匀度指数(J')分析群落多样性,结果表明春季和夏季的群落多样性相差不大,4个季节群落多样性存在明显变动。Margalef丰富度指数表明该调查水域受到中度干扰。5)聚类分析、nMDS和单因素方差分析(P=0.001)均支持群落结构存在季节差异,单因素方差分析不支持空间上的差异(P>0.05)。
      结论 杭州湾北部海域渔业资源密度、种类组成和群落结构存在明显季节性变动。
      意义 本研究补充了杭州湾北部海域渔业资源群落研究基础资料,可为其渔业资源评估和养护提供参考。

       

      Abstract:
      Objective To further understand the community structure characteristics of fishery resources in northern Hangzhou Bay, including species composition, resource density, dominant species, diversities and so on.
      Methods The fishery resources community structure was analyzed by using IRI, Cluster and nMDS based on the trawl survey data collected in August 2023 (summer), November 2023 (autumn), January 2024 (winter) and May 2024 (spring).
      Results 1) A total of 35 fishery species were investigated in four seasons, and the order of seasons was autumn (24 species) > summer (21 species) > spring (20 species) > winter (13 species). In any season, except winter, the species composition was mainly fishes, shrimps and crabs. The number of fish species in the four seasons was dominant. 2) The density of fishery resources in northern Hangzhou Bay changed seasonally. The order of individual resource density was summer (627 591.20 ind/km2) > spring (280 652.33 ind/km2) > autumn (277 154.35 ind/km2) > winter (58 831.26 ind/km2), and the order of weight resource density was summer (1 039.01 kg/km2) > spring (493.74 kg/km2 ) > autumn (211.32 kg/km2) > winter (129.78 kg/km2). 3) IRI study showed that the dominant species was only Palaemon annandalei in four seasons, and the seasonal change of main fishery species was obvious. The catch of four dominant species accounts for 69.26% in summer, 61.65% in autumn, 67.74% in winter and 81.85% in spring. 4) Margalef richness index (D), Shannon-Wiener diversity index (H') and Pielou’ evenness index (J') were used to analyze the community diversities. The results showed that there was little difference in community diversities between spring and summer, but there were obvious changes in community diversities among spring, summer, autumn and winter. Margalef species richness index indicated that the investigated waters were moderately disturbed. 5) Cluster, nMDS and one-way ANOVA (P=0.001) all supported the seasonal differences in community structure, while one-way ANOVA did not support the spatial differences (P>0.05).
      Conclusion The density, species composition and community structure of fishery resources in northern Hangzhou Bay have obviously seasonal changes.
      Significance This study supplements the basic data for the fishery resources community in northern Hangzhou Bay, providing reference for fishery resource assessment and conservation.

       

    /

    返回文章
    返回