舟山渔场主要虾类资源状况及与环境因子的关系

Shrimp resource dynamics and environmental drivers in the Zhoushan fishing ground

  • 摘要:
    目的 为未来舟山渔场的相关渔业活动开展以及渔业政策的发展提供一定的科学基础,促进渔业经济发展以及渔业政策的完善。
    方法 基于同期桁杆拖虾渔获日志数据,结合海水溶解氧(DO);海表温度(SST);海表盐度(SSS)和叶绿素a浓度(Chl.a)等遥感数据,运用渔场重心分析和广义相加模型(GAM)等方法,探讨了主要虾类资源分布及其与环境因子的关联。
    结果 舟山渔场拖虾渔获中以须赤虾 (23.30%)和大管鞭虾 (23.24%)为主。两虾类资源重心分布于30°10′~30°51′N、124°40′~125°01′E海域。2020—2021年及2023—2024年,资源重心波动较小;而2021—2023年则先向西南偏移,后转向东北。资源密度与年份、月份、经度、纬度均显著相关。影响大管鞭虾密度的关键环境因子为SST、DO和Chl.a,其适宜范围分别为14~23℃、200~250 mmol/m3和0~40 mg/m3;须赤虾则主要受SST和Chl.a影响,适宜SST为15~30℃,Chl.a为30~50 mg/m3
    结论 2020—2024年,舟山渔场虾类资源总体保持稳定,休渔期后渔获量与CPUE明显提升。极端天气及海洋环境波动对虾类资源的分布和产量产生显著影响。虾类资源分布重心呈波动变化,受关键环境因子以及渔业政策等共同作用。两种虾类CPUE表现出明显的时空差异,与繁殖期以及生长周期等密切相关。综合分析表明,SST、Chl.a和DO是影响舟山渔场虾类资源分布与丰度的主要因子,环境变化与渔业管理共同决定了虾类资源的时空动态特征。

     

    Abstract: This study investigated spatiotemporal variability in the major shrimp resources of the Zhoushan Fishing Ground from 2020 to 2024 and evaluated the development status of the beam trawl shrimp fishery, with the aim of providing a solid scientific basis for future fisheries policy development. Using contemporaneous beam trawl logbook data and remote-sensing–derived environmental variables-dissolved oxygen (DO), sea surface temperature (SST), sea surface salinity (SSS), and chlorophyll-a (Chl.a) concentration—we applied center-of-gravity analysis and generalized additive models (GAMs) to quantify distribution patterns of major shrimp resources and their associations with environmental drivers.The shrimp catch composition was dominated by Metapenaeopsis barbata (23.30%) and Solenocera crassicornis (23.24%). The centers of gravity of these two shrimp resources were located within 30°10′–30°51′N and 124°40′–125°01′E. The centers of gravity exhibited limited variability during 2020–2021 and 2023–2024, whereas they shifted southwestward from 2021 to 2022 and subsequently turned northeastward from 2022 to 2023. Resource density was significantly associated with year, month, longitude, and latitude. For S. crassicornis, the key environmental factors were SST, DO, and Chl.a, with optimal ranges of 14-23°C, 200-250 mmol/m3, and 0-40 mg/m3, respectively. In contrast, M. barbata was primarily influenced by SST and Chl.a, with optimal ranges of 15-30 °C and 30-50 mg/m3, respectively. Overall, shrimp resources remained generally stable from 2020 to 2024, and both catch and CPUE increased markedly following the seasonal fishing moratorium.Extreme weather events and oceanographic variability may substantially affect shrimp distribution and yield. The observed fluctuations in the distributional center of gravity may reflect the combined effects of environmental forcing and fisheries management policies. The CPUE of the two shrimp species showed pronounced spatiotemporal variability, closely related to their reproductive periods and growth cycles. Collectively, the results indicate that SST, Chl.a, and DO are dominant drivers of shrimp distribution and abundance in the Zhoushan Fishing Ground, and that environmental variability together with fisheries management jointly shapes the spatiotemporal dynamics of shrimp resources.

     

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