2022和2023年春季长江口邻近海域渔业群落结构变化及与环境因子的关系

Interannual variation of fishery community structure in the adjacent waters of the Yangtze River estuary in spring 2022-2023 and its relationship with environmental factors

  • 摘要:
    目的 为厘清渔业群落结构变化机制。
    方法 本研究基于2022—2023年连续两年春季在长江口海域开展的底拖网调查数据,分析了渔业生物的群落结构特征,包括种类组成、优势种和区系格局,并结合典范对应分析(CCA)与层次聚类法,探讨群落年际变化及其驱动因素。
    结果 结果表明,长江口渔业生物可划分为近岸(CJCA)、南部(CJSA)和北部(CJNA)三类群聚,分别以河口型、暖水型和冷水团控制种类为主。与2022年相比,2023年春季各类群的物种丰度和个体平均大小显著下降,但三类群之间在物种丰度和个体大小上的差异不显著。CCA分析显示,前两个排序轴共解释了25.5%的丰度-环境关系总变异,第1轴主要反映南北地理分布差异,受温度驱动;第2轴反映年际变化,可能与捕捞压力和盐度变化有关。
    结论 研究表明,长江口渔业生物群落的结构特征不仅受温度和盐度影响,还与人类捕捞强度密切相关。

     

    Abstract: In recent years, intensified human activities and climate change have increasingly impacted the community structure of fishery resources in the Yangtze River Estuary. To elucidate the mechanisms underlying changes in fishery community structure, this study analyzed data from spring bottom trawl surveys conducted continuously over two years (2022–2023) in the Yangtze River Estuary. Community structure characteristics, including species composition, dominant species, and zoogeographical patterns, were examined. Canonical correspondence analysis (CCA) and hierarchical clustering were applied to investigate interannual variations and driving factors of fishery communities. Results revealed that fishery assemblages clustered into three groups: nearshore (CJCA), southern (CJSA), and northern (CJNA) regions, dominated respectively by estuarine, warm-water, and cold-water fauna. Compared to 2022, both species abundance and mean individual size significantly decreased in 2023, while no significant differences in mean abundance or size were observed among the three clusters. CCA indicated that the first two axes explained 25.5% of the total variation in species–environment relationships, with axis 1 reflecting latitudinal distribution mainly driven by temperature, and axis 2 representing interannual variability likely associated with fishing pressure and salinity fluctuations. This study demonstrates that the fishery community structure in the Yangtze River Estuary is influenced not only by temperature and salinity but also by variations in fishing intensity.

     

/

返回文章
返回