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Ulaş A, Özgül A, Göktürk D. A case study on blast fishing in illegal small scale fisheries in the Aegean Sea: Catch composition and observed external and internal abnormalities for 18 Osteichthyes fish species. Mar Pollut Bull 2024; 203:116414. [PMID: 38701603 DOI: 10.1016/j.marpolbul.2024.116414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 04/19/2024] [Accepted: 04/20/2024] [Indexed: 05/05/2024]
Abstract
Blast fishing is an illegal, ecologically destructive fishing method, fatal for many fish species at large scales. Blast fishing using dynamite is preferred by the fishers, especially small scale fisheries in Turkey, as it requires minimal effort but still results in higher catches. In the current study, demonstration of 20 controlled real-time blasting results involves species composition, size of fish, catch rates, catch composition, commercial/discard ratios, CPUE estimates and clinical observations of external and internal abnormality symptoms of fish species. Blasting trials were carried out with special permission in limited numbers because of its harmful effect. The collected data was tested using PRIMER v6 and diversity indices were also analysed. For the similarity between collected species cluster analysis was used to examine the stability of the results. Multidimensional scaling (MDS) was also applied for the assessment of fish species in the catch. A total of 1014 individuals (63.8 kg) were collected and 18 fish species belonging to seven families were examined. According to laboratory examinations, it was found that blasting caused different external and internal abnormality symptoms in the sampled fish species during the study.
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Affiliation(s)
- Ali Ulaş
- Ege University, Faculty of Fisheries, Department of Fish Capture and Processing Technology, Fishing Technology Section, 35100 Bornova, Izmir, Turkey
| | - Aytaç Özgül
- Ege University, Faculty of Fisheries, Department of Fish Capture and Processing Technology, Fishing Technology Section, 35100 Bornova, Izmir, Turkey
| | - Didem Göktürk
- Istanbul University Faculty of Aquatic Sciences, Department of Fisheries Technology and Management, 34134 Fatih, Istanbul, Turkey.
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Zambrano A, Laguna MF, Kuperman MN, Laterra P, Monjeau JA, Nahuelhual L. A tragedy of the commons case study: modeling the fishers king crab system in Southern Chile. PeerJ 2023; 11:e14906. [PMID: 36935908 PMCID: PMC10022511 DOI: 10.7717/peerj.14906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 01/25/2023] [Indexed: 03/17/2023] Open
Abstract
Illegal fishing in small-scale fisheries is a contentious issue and resists a straightforward interpretation. Particularly, there is little knowledge regarding cooperative interactions between legal and illegal fishers and the potential effects on fisheries arising from these interactions. Taking the Chilean king crab (Lithodes santolla; common name centolla) fishery as a case study, our goal is twofold: (i) to model the effect of illegal-legal fishers' interactions on the fishery and (ii) analyze how management and social behavior affect fishery's outcomes. We framed the analysis of this problem within game theory combined with network theory to represent the architecture of competitive interactions. The fishers' system was set to include registered (legal) fishers and unregistered (illegal) fishers. In the presence of unregistered fishers, legal fishers may decide to cooperate (ignoring the presence of illegal fishers) or defect, which involves becoming a "super fisher" and whitewashing the captures of illegal fishers for a gain. The utility of both players, standard fisher and super fisher depend on the strategy chosen by each of them, as well as on the presence of illegal fishers. The nodes of the network represent the legal fishers (both standard and super fishers) and the links between nodes indicate that these fishers compete for the resource, assumed to be finite and evenly distributed across space. The decision to change (or not) the adopted strategy is modeled considering that fishers are subjected to variable levels of temptation to whitewash the illegal capture and to social pressure to stop doing so. To represent the vital dynamics of the king crab, we propose a model that includes the Allee effect and a term accounting for the crab extraction. We found that the super fisher strategy leads to the decrease of the king crab population under a critical threshold as postulated in the tragedy of the commons hypothesis when there are: (i) high net extraction rates of the network composed of non-competing standard fishers, (ii) high values of the extent of the fishing season, and (iii) high density of illegal fishers. The results suggest that even in the presence of super fishers and illegal fishers, the choice of properly distributed fishing/closure cycles or setting an extraction limit per vessel can prevent the king crab population from falling below a critical threshold. This finding, although controversial, reflects the reality of this fishery that, for decades, has operated under a dynamic in which whitewashing and super fishers have become well established within the system.
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Affiliation(s)
- Alan Zambrano
- Fundación Bariloche and CONICET, San Carlos de Bariloche, Argentina
| | - María F. Laguna
- Centro Atómico Bariloche - CONICET, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Río Negro, Argentina
| | - Marcelo N. Kuperman
- Centro Atómico Bariloche - CONICET, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Río Negro, Argentina
- Instituto Balseiro, Universidad Nacional de Cuyo, Cuyo, Mendoza, Argentina
| | - Pedro Laterra
- Fundación Bariloche and CONICET, San Carlos de Bariloche, Argentina
| | - Jorge A. Monjeau
- Fundación Bariloche and CONICET, San Carlos de Bariloche, Argentina
| | - Laura Nahuelhual
- Departamento de Ciencias Sociales, Universidad de Los Lagos, Osorno, Chile
- Instituto Milenio en Socio-Ecología Costera, Santiago, Chile
- Centro de Investigación, Dinámica de Ecosistemas Marinos de Altas Latitudes, Chile
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Zhuang W, Liu M, Gao Z. A new method for quantifying the value of ecological environment damage caused by illegal fishing: A case study. Mar Pollut Bull 2021; 172:112819. [PMID: 34392156 DOI: 10.1016/j.marpolbul.2021.112819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/30/2021] [Accepted: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Illegal fishing may trigger structural disruption of the food chain and even damage the entire marine ecosystem. This paper proposes a new method for quantifying the value of eco-environment damage caused by illegal fishing; as an example, we used an illegal fishing case of anchovies in the vicinity of the Yellow River Delta National Nature Reserve. Based on the data from the field investigation and literature, we estimated the number and age distribution of illegally harvested anchovies. Additionally, the potential number of the offspring was calculated according to the potential number and survival rate of anchovy eggs. Due to the unavailability of commercial anchovy fries, "alternative stock enhancement" was recommended to restore the damaged eco-environment. Notably, the alternative species should have similar economic value, status in the food chain, and living areas to anchovies. Eventually, we selected Liza haematocheilus as the alternative species and calculated the total eco-environment recovery cost.
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Affiliation(s)
- Wen Zhuang
- Institute of Eco-environmental Forensics, Shandong University, Qingdao, Shandong 266237, China; Ministry of Justice Hub for Research and Practice in Eco-Environmental Forensics, Shandong University, Qingdao, Shandong 266237, China.
| | - Min Liu
- Institute of Eco-environmental Forensics, Shandong University, Qingdao, Shandong 266237, China; Ministry of Justice Hub for Research and Practice in Eco-Environmental Forensics, Shandong University, Qingdao, Shandong 266237, China
| | - Zhenhui Gao
- Institute of Eco-environmental Forensics, Shandong University, Qingdao, Shandong 266237, China; Ministry of Justice Hub for Research and Practice in Eco-Environmental Forensics, Shandong University, Qingdao, Shandong 266237, China; First Institute of Oceanography, Ministry of Natural Resources, Qingdao, Shandong 266061, China
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Longépé N, Hajduch G, Ardianto R, Joux RD, Nhunfat B, Marzuki MI, Fablet R, Hermawan I, Germain O, Subki BA, Farhan R, Muttaqin AD, Gaspar P. Completing fishing monitoring with spaceborne Vessel Detection System (VDS) and Automatic Identification System (AIS) to assess illegal fishing in Indonesia. Mar Pollut Bull 2018; 131:33-39. [PMID: 29106935 DOI: 10.1016/j.marpolbul.2017.10.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 09/29/2017] [Accepted: 10/06/2017] [Indexed: 06/07/2023]
Abstract
The Indonesian fisheries management system is now equipped with the state-of-the-art technologies to deter and combat Illegal, Unreported and Unregulated (IUU) fishing. Since October 2014, non-cooperative fishing vessels can be detected from spaceborne Vessel Detection System (VDS) based on high resolution radar imagery, which directly benefits to coordinated patrol vessels in operation context. This study attempts to monitor the amount of illegal fishing in the Arafura Sea based on this new source of information. It is analyzed together with Vessel Monitoring System (VMS) and satellite-based Automatic Identification System (Sat-AIS) data, taking into account their own particularities. From October 2014 to March 2015, i.e. just after the establishment of a new moratorium by the Indonesian authorities, the estimated share of fishing vessels not carrying VMS, thus being illegal, ranges from 42 to 47%. One year later in January 2016, this proportion decreases and ranges from 32 to 42%.
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Affiliation(s)
- Nicolas Longépé
- Space and Ground Segment, Collecte Localisation Satellites (CLS), Plouzané, France.
| | - Guillaume Hajduch
- Space and Ground Segment, Collecte Localisation Satellites (CLS), Plouzané, France
| | - Romy Ardianto
- Agency for Marine and Fisheries Research and Development - MMAF, Jakarta, Indonesia
| | - Romain de Joux
- Space and Ground Segment, Collecte Localisation Satellites (CLS), Plouzané, France
| | - Béatrice Nhunfat
- Space and Ground Segment, Collecte Localisation Satellites (CLS), Plouzané, France
| | - Marza I Marzuki
- Agency for Marine and Fisheries Research and Development - MMAF, Jakarta, Indonesia; Institut Mines-Télécom/Télécom Bretagne, CNRS UMR 6285 Lab-STICC, France
| | - Ronan Fablet
- Institut Mines-Télécom/Télécom Bretagne, CNRS UMR 6285 Lab-STICC, France
| | - Indra Hermawan
- Agency for Marine and Fisheries Research and Development - MMAF, Jakarta, Indonesia
| | - Olivier Germain
- Space and Ground Segment, Collecte Localisation Satellites (CLS), Plouzané, France
| | - Berny A Subki
- Agency for Marine and Fisheries Research and Development - MMAF, Jakarta, Indonesia
| | - Riza Farhan
- Agency for Marine and Fisheries Research and Development - MMAF, Jakarta, Indonesia
| | - Ahmad Deni Muttaqin
- Agency for Marine and Fisheries Research and Development - MMAF, Jakarta, Indonesia
| | - Philippe Gaspar
- Sustainable Management of Fisheries, Collecte Localisation Satellites (CLS), Ramonville Saint-Agne, France
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