浙江南部近海鱼类资源季节分布特征及其影响因素

Distribution Characteristics and Influencing Factors of Fish Resources in the Offshore Waters South of Zhejiang

中文关键词: 广义加性模型  鱼类资源  资源分布  环境因子  浙江南部近海

英文关键词: Generalized additive models  Fishery resources  Resource distribution  Environmental factor  Offshore south of Zhejiang

中文摘要:

      根据2016—2020年浙江南部鱼类资源调查数据，运用广义加性模型研究浙江南部各季节鱼类资源与环境因子的关系，并基于2020年环境数据探究鱼类资源时空分布特征。结果显示，春季、夏季、秋季和冬季最佳模型的偏差解释率分别为47.9%、68.0%、56.6%和45.6%，交叉验证回归线的斜率平均值为0.74~1.02，模型拟合能力和预测能力良好。水温、盐度和叶绿素是影响浙江南部海域鱼类资源密度的主要因子，在不同季节对鱼类资源密度有不同的影响机制。水温在夏季和秋季对鱼类资源密度影响极显著(P<0.01)，秋季，水温和资源密度之间存在显著负相关(r= –0.225, P<0.05)；盐度在不同季节对鱼类资源密度的影响也存在差异，秋季，鱼类资源密度随着盐度的增加而增加，冬季则呈先增加后减小的变化趋势，且在盐度为31.5时达到最大值；除冬季外，其他季节叶绿素浓度与鱼类资源密度均显著相关(P<0.05)。研究表明，2020年春季、夏季鱼类资源密度相对较高，秋季和冬季鱼类资源密度则相对偏低。空间上，春季，温台渔场的鱼类资源密度明显高于鱼山渔场；夏季，温台渔场和鱼山渔场鱼类资源均较为集中，主要分布在27.8°~28.4°N、121.7°~122.9°E以及28.9°N、122°E海域附近。

英文摘要:

      Based on fishery-independent survey data from 2016 to 2020 in the offshore waters south of Zhejiang, the relationship between fish resource density and environmental factors was explored using a generalized additive model, and the spatial and temporal distribution of fish resource density was predicted using the optimal models and environmental data of 2020. The results showed that the optimal models had deviances of 47.9%, 68.0%, 56.6% and 45.6% in spring, summer, autumn, and winter, respectively. The average slope of the cross-validation regression line was 0.74–1.02, and the model had good fitting and prediction abilities. Water temperature, salinity, and chlorophyll were significant factors that affected fish resource density in the offshore waters south of Zhejiang, and they had different influencing mechanisms in different seasons. In general, in summer and autumn, water temperature had a significant impact on fish resource density (P<0.01). And there is a negative correlation between water temperature and fish resource density in autumn (r= –0.225, P<0.05). In autumn, fish density increased with an increase in salinity, and in winter, fish density first increased and then decreased, reaching the maximum value at a salinity of 31.5. In spring, summer and autumn, chlorophyll was significantly correlated with fish resource density (P<0.05). Overall, the results showed that the fish resource density in autumn and winter was relatively lower than that in spring and summer in 2020. In spring, the fish resources in Wentai fishing ground were significantly greater than those in Yushan fishing ground. In summer, fish resources in Wentai and Yushan fishing grounds were relatively concentrated, primarily distributed at 27.8°~28.4°N, 121.7°~122.9°E and at 28.9°N, 122°E, respectively.