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Louhichi M, Girard A, Jribi I. Fishermen Interviews: A Cost-Effective Tool for Evaluating the Impact of Fisheries on Vulnerable Sea Turtles in Tunisia and Identifying Levers of Mitigation. Animals (Basel) 2023; 13:ani13091535. [PMID: 37174572 PMCID: PMC10177481 DOI: 10.3390/ani13091535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/17/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023] Open
Abstract
Fisheries bycatch is considered one of the main threats to sea turtles. To provide an updated assessment of the bycatch impact on loggerhead turtles in Tunisia, 483 interviews were conducted with fishermen in 19 ports along the Gulfs of Gabes and Hammamet. The interview questions included data on vessel and fishing gear characteristics, monthly fishing effort, and monthly sea turtle bycatch of the last year. Results revealed that sea turtle bycatch per unit effort (BPUE) was the highest for ray nets (0.73 turtles/vessel/day, 95% CI [0.02-1.15]), followed by pelagic longlines (0.6 turtles/vessel/day, 95% CI [0-4.23]) and shark nets (0.4 turtles/vessel/day, 95% CI [0-2.12]). However, due to the trawlers' high fishing effort, the cumulative impact of the trawl nets was the highest with an estimated number of 11,740 (95% CI [0-41,525.75]) turtles caught per year in Tunisia. Factors influencing the bycatch risk were gear characteristics (mesh size for nets, hook size for longlines, vertical opening for trawls), as well as season and location of operations. These factors will guide the research of mitigation solutions. The interviews with fishermen proved to be a cost-effective approach for the rapid assessment of sea turtle interactions with fisheries in the context of Tunisia.
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Affiliation(s)
- Maissa Louhichi
- BIOME Lab, Sfax Faculty of Sciences, Univerity of Sfax P.O. Box 1171, Sfax 3000, Tunisia
| | - Alexandre Girard
- PatriNat, Muséum National d'Histoire Naturelle, rue Buffon, 75005 Paris, France
| | - Imed Jribi
- BIOME Lab, Sfax Faculty of Sciences, Univerity of Sfax P.O. Box 1171, Sfax 3000, Tunisia
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Petetta A, Herrmann B, Li Veli D, Virgili M, De Marco R, Lucchetti A. Every animal matters! Evaluating the selectivity of a Mediterranean bottom trawl fishery from a species community perspective. PLoS One 2023; 18:e0283362. [PMID: 36952504 PMCID: PMC10035856 DOI: 10.1371/journal.pone.0283362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 03/07/2023] [Indexed: 03/25/2023] Open
Abstract
Bottom trawl fisheries often catch several species simultaneously. However, most studies addressing the catch performance and selectivity of a specific trawl focus on a few commercially important or most vulnerable species requiring management measures. By contrast, the present study considers the multispecies nature of Mediterranean bottom trawl fisheries through a holistic approach that accounts for the full species community in the catches. Specifically, we evaluated and compared the catch performance of the two codends allowed for this fishery, made of 40 mm square (SM40) and 50 mm diamond (DM50) meshes. Results showed that 50 and 80% of the catch in weight and count numbers, respectively, consisted of species without commercial value, demonstrating that large proportions of the catch are not considered when using the existing approach to evaluate the ecological impact of the fishing activity. Significant differences in catch profiles between the two codends were observed, especially for two commercial flatfish species, Arnoglossus laterna and Citharus linguatula, with larger contributions in the SM40. Further, the SM40 codend had a significantly higher retention, compared to DM50 codend, for specific sizes of Merluccius merluccius and Mullus barbatus. The outcomes of the study can be useful for the Mediterranean bottom trawl fisheries management.
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Affiliation(s)
- Andrea Petetta
- Department of Biological, Geological and Environmental Sciences (BIGEA), University of Bologna (UNIBO), Bologna, Italy
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council (CNR), Ancona, Italy
- * E-mail:
| | - Bent Herrmann
- The Arctic University of Norway UIT, Tromsø, Norway
- SINTEF Ocean, Fishing Gear Technology, Trondheim, Norway
- Technical University of Denmark, National Institute of Aquatic Resources, Hirtshals, Denmark
| | - Daniel Li Veli
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council (CNR), Ancona, Italy
| | - Massimo Virgili
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council (CNR), Ancona, Italy
| | - Rocco De Marco
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council (CNR), Ancona, Italy
| | - Alessandro Lucchetti
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), National Research Council (CNR), Ancona, Italy
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Margaritoulis D, Lourenço G, Riggall TE, Rees AF. Thirty-Eight Years of Loggerhead Turtle Nesting in Laganas Bay, Zakynthos, Greece: A Review. CHELONIAN CONSERVATION AND BIOLOGY 2022. [DOI: 10.2744/ccb-1531.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Dimitris Margaritoulis
- ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, GR-10432 Athens, Greece [; ; ; ]
| | - Gonçalo Lourenço
- ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, GR-10432 Athens, Greece [; ; ; ]
| | - Thomas E. Riggall
- ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, GR-10432 Athens, Greece [; ; ; ]
| | - Alan F. Rees
- ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, GR-10432 Athens, Greece [; ; ; ]
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Analysis of risk factors associated with gas embolism and evaluation of predictors of mortality in 482 loggerhead sea turtles. Sci Rep 2021; 11:22693. [PMID: 34811412 PMCID: PMC8608947 DOI: 10.1038/s41598-021-02017-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 11/08/2021] [Indexed: 11/08/2022] Open
Abstract
Sea turtles that are entrapped in static and towed nets may develop gas embolism which can lead to severe organ injury and death. Trawling characteristics, physical and physiologic factors associated with gas-embolism and predictors of mortality were analysed from 482 bycaught loggerheads. We found 204 turtles affected by gas-embolism and significant positive correlations between the presence of gas-embolism and duration, depth, ascent rate of trawl, turtle size and temperature, and between mortality and ascent time, neurological deficits, significant acidosis and involvement of > 12 cardiovascular sites and the left atrium and sinus venosus-right atrium. About 90% turtles with GE alive upon arrival at Sea Turtle Clinic recovered from the disease without any supportive drug therapy. Results of this study may be useful in clinical evaluation, prognostication, and management for turtles affected by gas-embolism, but bycatch reduction must become a priority for major international organizations. According to the results of the present study the measures to be considered to reduce the catches or mortality of sea turtles for trawling are to be found in the modification of fishing nets or fishing operations and in greater awareness and education of fishermen.
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Petetta A, Vasapollo C, Virgili M, Bargione G, Lucchetti A. Pots vs trammel nets: a catch comparison study in a Mediterranean small-scale fishery. PeerJ 2020; 8:e9287. [PMID: 32742763 PMCID: PMC7370935 DOI: 10.7717/peerj.9287] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/13/2020] [Indexed: 11/21/2022] Open
Abstract
Passive bottom-set nets are the most widely used fishing gears in Mediterranean small-scale fisheries (SSFs). Trammel nets, in particular, have key advantages such as their ease of use and handling and high capture efficiency for numerous commercial species. However, they entail high discard rates (5–44% of the total catch) connected to high mortality, thus exerting an adverse impact on benthic communities, besides catching individuals of commercial species under the minimum conservation reference size (MCRS) and specimens of protected species. Fish pots are seen as alternative and a more sustainable gear type that allow reducing discards in SSFs. In this study, a collapsible pot was tested at three coastal sites in the north-western Adriatic Sea (GFCM GSA 17) to compare its catch efficiency with that of the local traditional trammel nets. Data analysis demonstrated a similar catch efficiency for the commercial species, both among sites and as a whole. Moreover, the trammel net caught a larger amount of discards, both in terms of species number and of CPUEW. The catch comparison study involved the two most abundant landed species, common cuttlefish Sepia officinalis and annular sea bream Diplodus annularis. The pots were more effective for S. officinalis, whereas the trammel net was more effective for the shorter length classes for D. annularis, which were mostly under the MCRS (12 cm). The innovative pots could provide a valuable alternative to the trammel nets traditionally used in the Adriatic Sea, at least in certain areas and periods. Their main advantages include that they do not require a different rigging and they can be used without bait, while their foldable design allows large numbers to be easily loaded on board SSF vessels. The results of this pilot study indicate that pots can achieve the objectives of reducing discards and bycatch in SSFs without penalizing the catch of commercial species.
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Affiliation(s)
- Andrea Petetta
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy.,Institute for Biological Resources and Marine Biotechnologies (IRBIM), Italian National Research Council (CNR), Ancona, Italy
| | - Claudio Vasapollo
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), Italian National Research Council (CNR), Ancona, Italy
| | - Massimo Virgili
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), Italian National Research Council (CNR), Ancona, Italy
| | - Giada Bargione
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy.,Institute for Biological Resources and Marine Biotechnologies (IRBIM), Italian National Research Council (CNR), Ancona, Italy
| | - Alessandro Lucchetti
- Institute for Biological Resources and Marine Biotechnologies (IRBIM), Italian National Research Council (CNR), Ancona, Italy
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Stelfox M, Bulling M, Sweet M. Untangling the origin of ghost gear within the Maldivian archipelago and its impact on olive ridley (Lepidochelys olivacea) populations. ENDANGER SPECIES RES 2019. [DOI: 10.3354/esr00990] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Vasapollo C, Virgili M, Petetta A, Bargione G, Sala A, Lucchetti A. Bottom trawl catch comparison in the Mediterranean Sea: Flexible Turtle Excluder Device (TED) vs traditional gear. PLoS One 2019; 14:e0216023. [PMID: 31800581 PMCID: PMC6892479 DOI: 10.1371/journal.pone.0216023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 11/14/2019] [Indexed: 11/18/2022] Open
Abstract
The Mediterranean Sea is a biodiversity hotspot where intense fishing pressure is associated with high bycatch rates of protected species (sea turtles and cetaceans) and top predators (sharks). Since the conservation of these species has become a priority, fishery scientists are faced with the challenge of reducing incidental catch, which entails high rates of mortality. Among the species threatened by fishing activities, the loggerhead turtle (Caretta caretta) is a charismatic species considered as "vulnerable" at the global scale. In the Mediterranean Sea trawl nets are the gears with the highest probability of catching protected species incidentally. A new flexible Turtle Excluder Device (TED) was tested for the first time on commercial bottom trawlers to assess its effectiveness in reducing bycatch in the Mediterranean Sea. Analysis of the total catches of the hauls made with and without the TED showed that the difference in terms of weight was not significant. The catch of the main commercial species showed similar rates without a significant loss of size (i.e. total length) with the exception of the largest anglerfish (Lophius spp.). The bycatch of control nets included mostly rays and sharks, but never turtles, although the authors learned from the crews of other vessels operating in the same areas at the time of the trials that they had caught some loggerhead turtles. Our study demonstrates that TED scan be adopted without significantly affecting commercial catch. This informs fishers and managers for a practical and effective means that may reduce the bycatch of threatened species in coastal Mediterranean demersal multispecies fisheries. The measures involving gear modifications require significant investment but they are technically feasible and are capable of improving the conservation prospects of these endangered species. Besides ensuring normal earnings, the TED induced a significant reduction of debris and litter in the codend, thus reducing catch sorting time and improving catch quality.
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Affiliation(s)
- Claudio Vasapollo
- National Research Council (CNR), Institute of Biological Resources and Marine Biotechnologies (IRBIM), Largo Fiera della Pesca, Ancona, Italy
| | - Massimo Virgili
- National Research Council (CNR), Institute of Biological Resources and Marine Biotechnologies (IRBIM), Largo Fiera della Pesca, Ancona, Italy
| | - Andrea Petetta
- National Research Council (CNR), Institute of Biological Resources and Marine Biotechnologies (IRBIM), Largo Fiera della Pesca, Ancona, Italy
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Piazza di Porta San Donato, Bologna, Italy
| | - Giada Bargione
- National Research Council (CNR), Institute of Biological Resources and Marine Biotechnologies (IRBIM), Largo Fiera della Pesca, Ancona, Italy
- Department of Biological, Geological and Environmental Sciences, University of Bologna, Piazza di Porta San Donato, Bologna, Italy
| | - Antonello Sala
- National Research Council (CNR), Institute of Biological Resources and Marine Biotechnologies (IRBIM), Largo Fiera della Pesca, Ancona, Italy
| | - Alessandro Lucchetti
- National Research Council (CNR), Institute of Biological Resources and Marine Biotechnologies (IRBIM), Largo Fiera della Pesca, Ancona, Italy
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Ayala L, Ortiz M, Gelcich S. Exploring the role of fishers knowledge in assessing marine megafauna bycatch: insights from the Peruvian longline artisanal fishery. Anim Conserv 2018. [DOI: 10.1111/acv.12460] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- L. Ayala
- Programa de Doctorado en Ciencias Aplicadas Mención Sistemas Marinos Costeros Facultad de Recursos del Mar Universidad de Antofagasta Antofagasta Chile
- Asociación Peruana para la Conservación de la Naturaleza‐APECO Lima Perú
| | - M. Ortiz
- Instituto Antofagasta Instituto de Investigaciones Oceanológicas Facultad de Recursos del Mar Universidad de Antofagasta Antofagasta Chile
| | - S. Gelcich
- Center of Applied Ecology and Sustainability (CAPES) & Center for the Study of Multiple‐Drivers on Marine Socio‐Ecological Systems (MUSELS) Departamento de Ecologia Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
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Caracappa S, Persichetti MF, Piazza A, Caracappa G, Gentile A, Marineo S, Crucitti D, Arculeo M. Incidental catch of loggerhead sea turtles ( Caretta caretta) along the Sicilian coasts by longline fishery. PeerJ 2018; 6:e5392. [PMID: 30123712 PMCID: PMC6086082 DOI: 10.7717/peerj.5392] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/17/2018] [Indexed: 11/25/2022] Open
Abstract
It has been estimated that 44,000 Caretta caretta turtles die every year due to anthropomorphic activity in the Mediterranean Sea, and that longline fishing is one of the most significant causes of mortality. A total of 482 specimens of C. caretta were rescued from different parts of the Sicilian coast (Mediterranean Sea) from 2014 to 2016. The most numerous stranding was recorded during the spring and summer seasons, mainly along the north and eastern coasts of Sicily. The curved carapace length for all the specimens ranged from between 19 and 95 cm and most of these were young or sub adults. The highest number of strandings was recorded in 2014 and 2015, with 206 and 169 individuals, respectively. A total of 66 live specimens out of 239 were successfully rehabilitated and released after surgery or drug therapy; fishing hooks were found in 129 specimens in different parts of the digestive tract with greater frequency in the oesophagus (47.3%) followed by the gut (24.8%), stomach (14.7%), and mouth (13.2%). This paper will highlight the incidence of the incidental catch by longline fishing of C. caretta along the Sicilian coasts and also relate the size of ingested hooks to the size of examined specimens.
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Affiliation(s)
- Santo Caracappa
- Istituto Zooprofilattico Sperimentale della Sicilia, Palermo, Italy
| | | | - Antonio Piazza
- Istituto Zooprofilattico Sperimentale della Sicilia, Palermo, Italy
| | - Giulia Caracappa
- Istituto Zooprofilattico Sperimentale della Sicilia, Palermo, Italy
| | - Antonino Gentile
- Istituto Zooprofilattico Sperimentale della Sicilia, Palermo, Italy
| | - Sandra Marineo
- Istituto Zooprofilattico Sperimentale della Sicilia, Palermo, Italy
| | - Daniela Crucitti
- Istituto Zooprofilattico Sperimentale della Sicilia, Palermo, Italy
| | - Marco Arculeo
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, University of Palermo, Palermo, Italy
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Casale P, Broderick AC, Camiñas JA, Cardona L, Carreras C, Demetropoulos A, Fuller WJ, Godley BJ, Hochscheid S, Kaska Y, Lazar B, Margaritoulis D, Panagopoulou A, Rees AF, Tomás J, Türkozan O. Mediterranean sea turtles: current knowledge and priorities for conservation and research. ENDANGER SPECIES RES 2018. [DOI: 10.3354/esr00901] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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