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He B, Yan F, Su F, Lyne V, Tang J. Prediction of fishing intensity and trends across South China Sea biogeographic zones. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 899:165691. [PMID: 37482352 DOI: 10.1016/j.scitotenv.2023.165691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/06/2023] [Accepted: 07/19/2023] [Indexed: 07/25/2023]
Abstract
The volume of industrial fishing in the South China Sea ranks among the top global sustainable fisheries concerns of the Food and Agriculture Organization (FAO). To better understand the scale of management challenges, biogeographic zones of the SCS were characterized, and within each a multivariate GAM (General Additive Model) was fitted to predict and map the complete fishing activities from 2017 to 2020. Model variables, some incomplete or with gaps, included: VIIRS DNB night-time light imagery; Global Fisheries Watch (GFW) data; satellite Ocean Colour; Sea Surface Temperature; and bathymetry data. Four biogeographic zones with differing fishing patterns and trends were identified. We used cross-validation and the GAM model's own tuning method for model prediction accuracy determination, which performed well in four biogeographic zones (R2 respectively: 0.62, 0.68, 0.74 and 0.71). High-intensity fishing grounds are mainly distributed in offshore continental shelf areas. From 2017 to 2019, high-intensity fishing grounds were located near the Beibu Gulf of Vietnam, south Vietnam, part of the Gulf of Thailand and the central Java Sea, where fishing effort greater than 50 h exceeded average annual SCS fishing intensity for several years. By season, intensity and extent of fishing in Spring were largest. In 2020, due to the impact of COVID-19, except for Spring, fishing volume generally decreased. Our experimental results provide new insights and an adaptable biogeographic modelling methodology to map the scale and intensity of regional fishing activities more accurately and completely. This more comprehensive database, that takes account of intrinsic biogeographic fishery context, will help improve and strengthen the regulation of fishing activities around the world.
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Affiliation(s)
- Bin He
- School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Collaborative Innovation Center for the South China Sea Studies, Nanjing University, Nanjing 210023, China.
| | - Fengqin Yan
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Collaborative Innovation Center for the South China Sea Studies, Nanjing University, Nanjing 210023, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Fenzhen Su
- School of Geography and Ocean Science, Nanjing University, Nanjing 210023, China; State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Collaborative Innovation Center for the South China Sea Studies, Nanjing University, Nanjing 210023, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Vincent Lyne
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; IMAS-Hobart, University of Tasmania, Hobart, TAS 7004, Australia.
| | - Jiasheng Tang
- State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; Faculty of Geomatics, Lanzhou Jiaotong University, Lanzhou, China.
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Ferreira A, Garrido S, Costa JL, Teles-Machado A, Brotas V, Brito AC. What drives the recruitment of European sardine in Atlanto-Iberian waters (SW Europe)? Insights from a 22-year analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163421. [PMID: 37059140 DOI: 10.1016/j.scitotenv.2023.163421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/30/2022] [Accepted: 04/06/2023] [Indexed: 06/01/2023]
Abstract
The European sardine (Sardina pilchardus) is the most abundant and socio-economically important small pelagic fish species in Western Iberia Upwelling Ecosystem. As a result of a long series of low recruitments, sardine biomass off Western Iberia has greatly reduced since the 2000s. Recruitment of small pelagic fish is mainly dependent on environmental factors. In order to identify the key drivers of sardine recruitment, it is essential to understand its temporal and spatial variability. To achieve this goal, a comprehensive suite of atmospheric, oceanographic, and biological variables spanning 1998-2020 (22 years) were extracted from satellite datasets. These were then related to in situ recruitment estimates obtained from yearly spring acoustic surveys carried out along two different hotspots of sardine recruitment of the southern Iberian sardine stock (NW Portugal and Gulf of Cadiz). Sardine recruitment in Atlanto-Iberian waters appears to be driven by distinct combinations of environmental factors, although sea surface temperature was identified as the main driver in both regions. Physical conditions that favour larval feeding and retention, such as shallower mixed layers and onshore transport, were also seen to play a vital role in modulating sardine recruitment. Furthermore, high sardine recruitment in NW Iberia was associated with optimal conditions in the winter (January-February). In contrast, recruitment strength of sardine off the Gulf of Cadiz were associated with the optimal conditions during late autumn and spring. The results from this work provide valuable insights to further understand the dynamics of sardine off Iberia, with potential to contribute to the sustainable management of sardine stocks in Atlanto-Iberian waters, particularly under climate change.
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Affiliation(s)
- Afonso Ferreira
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Susana Garrido
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Portuguese Institute for the Sea and Atmosphere - IPMA, Av. Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Lisboa, Portugal
| | - José Lino Costa
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Ana Teles-Machado
- Portuguese Institute for the Sea and Atmosphere - IPMA, Av. Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Lisboa, Portugal; IDL - Instituto Dom Luiz, Portuguese Institute for the Sea and Atmosphere, Av. Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Lisboa, Portugal
| | - Vanda Brotas
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Ana C Brito
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
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