Laboratory of Fisheries Ecosystem Monitoring and Assessment, College of Fisheries, Ocean University of China, Qingdao 266003, China; Field Observation and Research Station of Haizhou Bay Fishery Ecosystem, Ministry of Education, Qingdao 266003, China.
Laboratory for Marine Fisheries and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China; Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
Sci Total Environ. 2021 Apr 1;763:144205. doi: 10.1016/j.scitotenv.2020.144205. Epub 2020 Dec 25.
El Niño events have great impacts on marine ecosystems worldwide, ranging from low trophic plankton production to fishery resources. Understanding how ecosystems respond to El Niño is the key to the success of ecosystem-based fisheries management (EBFM). However, few studies have focussed on the ecosystems respond to this natural perturbation in China seas, and the selection of effective ecological network analyses (ENA) indicators to evaluate the ecosystem response under El Niño conditions needs to be assessed. In this study, we constructed Ecopath models for Haizhou Bay in ENSO-neutral (2013) and El Niño (2015) years. Comprehensive analyses were conducted to evaluate ENA indicators in terms of sensitivity to the ecosystem variations, robustness to the model parameters uncertainties, and statistical check. Results showed that there were obvious variations in the species composition and biomass in the Haizhou Bay ecosystem under the El Niño event. Four optimal ENA indicators were selected, including total system throughput, total primary production, total system non-cycled throughflow, and ascendency. The indicators further showed a shrunken ecosystem size, increased energetic efficiency, and less organised ecosystem under the El Niño event. These findings enhance our understanding of ecosystem dynamics and underscore the need for precautionary management under El Niño conditions. Moreover, this work can be helpful in guiding the further selection of ENA indicators for evaluating and managing marine ecosystems during El Niño events elsewhere and thusly contribute to the implementation of EBFM.
厄尔尼诺事件对全球海洋生态系统有重大影响，从低营养级浮游生物的生产到渔业资源都受到影响。了解生态系统对厄尔尼诺的响应是基于生态系统的渔业管理（EBFM）成功的关键。然而，在中国海域，很少有研究关注生态系统对这种自然干扰的响应，并且需要评估选择有效的生态网络分析（ENA）指标来评估厄尔尼诺条件下的生态系统响应。在这项研究中，我们为厄尔尼诺中性年（2013 年）和厄尔尼诺年（2015 年）的海州湾构建了生态路径模型。进行了综合分析，以评估 ENA 指标在对生态系统变化的敏感性、对模型参数不确定性的稳健性以及统计检验方面的表现。结果表明，在厄尔尼诺事件下，海州湾生态系统的物种组成和生物量有明显变化。选择了四个最佳的 ENA 指标，包括总系统吞吐量、总初级生产力、总系统无循环通过流量和优势度。这些指标进一步表明，在厄尔尼诺事件下，生态系统规模缩小，能量效率提高，生态系统组织程度降低。这些发现增强了我们对生态系统动态的理解，并强调了在厄尔尼诺条件下需要进行预防性管理。此外，这项工作有助于指导在其他地方的厄尔尼诺事件期间评估和管理海洋生态系统时进一步选择 ENA 指标，从而有助于实施 EBFM。
