Article
Oceanography
Fabien Forget, Jeff Muir, Melanie Hutchinson, David Itano, Igor Sancristobal, Bruno Leroy, John Filmalter, Udane Martinez, Kim Holland, Victor Restrepo, Laurent Dagorn
Summary: Estimating bycatch is crucial for monitoring fisheries' ecological impacts. The study found that shark counts were often underestimated during commercial fishing trips, especially by single onboard observers or Electronic Monitoring Systems. Specific studies using complementary counts by two onboard observers are recommended to assess the accuracy of different EMS configurations.
OCEAN & COASTAL MANAGEMENT
(2021)
Article
Ecology
Pauline Stephan, Daniel Gaertner, Ilan Perez, Lorelei Guery
Summary: This article introduces a method that combines self-organizing maps (SOMs) with a clustering approach to analyze fisheries data. By converting the data into simple geographic maps showing catch hotspots, the method can indicate sensitive areas in fishery management. Testing on simulated and real datasets demonstrates that this method provides scientific support and aids in decision-making for fisheries management.
METHODS IN ECOLOGY AND EVOLUTION
(2022)
Article
Environmental Sciences
Jefferson Murua, Gala Moreno, Laurent Dagorn, David Itano, Martin Hall, Hilario Murua, Victor Restrepo
Summary: More than a decade of collaborative efforts with tropical tuna purse seine fleets has resulted in the development of sustainable fishing practices worldwide. Through participatory workshops organized by the ISSF, scientists, fishers, and stakeholders have worked together to minimize fishery impacts. These workshops have reached fleet members in 23 countries, and the discussions have led to novel solutions and a better understanding of ecosystem dynamics. The testing and adoption of these solutions, as well as the increased trust and stewardship of fishers, have contributed to large-scale research projects and the adoption of best practices for impact mitigation.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Fisheries
John D. Filmalter, Robert K. Bauer, Fabien Forget, Paul D. Cowley, Laurent Dagorn
Summary: The study found that silky sharks have high overlap with FADs and fishing vessel positions, highlighting the need for compliance with FAD design regulations to prevent entanglement, while the overlap with tuna catches is more variable. The observed movement patterns suggest that static spatial management measures may have limited conservation impact, whereas dynamic approaches may be more suitable.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Ecology
Karine Briand, Philippe S. Sabarros, Alexandra Maufroy, Anne-Lise Vernet, Arthur Yon, Antoine Bonnieux, Michel Goujon, Pascal Bach
Summary: This study used Electronic Monitoring Systems (EMS) installed on board French tropical tuna purse seiners to examine the sorting process and optimize observer sampling strategies for obtaining robust estimates of discards. The results showed differences in the flow of discards among species and sorting locations and recommended specific observer sampling strategies for accurate discard estimation. The study also discussed strategies to improve discard estimation combining onboard and electronic observations.
REGIONAL STUDIES IN MARINE SCIENCE
(2023)
Article
Biodiversity Conservation
Siosaia Vaihola, Dawit Yemane, Stuart Kininmonth
Summary: The Tongan fisheries targeting albacore, bigeye, skipjack, and yellowfin tuna within the EEZ of Tonga are crucial to the economy. This study examines the spatiotemporal distribution of these species and their dependence on environmental and physical variables. Generalized additive models were used, along with predictors such as sea surface temperature, sea surface chlorophyll, bottom depth, month, and year. The study finds that catch year is the most important variable for most species, followed by sea surface temperature and bottom depth.
Article
Fisheries
Nelly Pena-Cutimbo, Cristel Cordero-Maldonado, Clara Ortiz-Alvarez, Joanna Alfaro-Shigueto, Jeffrey C. Mangel
Summary: Bycatch is a global problem for marine megafauna. This study assessed the bycatch interactions of the Peruvian artisanal purse-seine fishery in 2019 and found that all taxa groups were affected by bycatch. Dusky dolphins, guanay cormorants, and eagle rays were the most frequently reported bycatch species.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Reka Domokos
Summary: Bigeye tuna and yellowfin tuna are economically important species in global pelagic fisheries, especially for tropical Pacific nations. The El Nino-Southern Oscillation (ENSO) has a significant impact on the oceanographic conditions and fishing grounds of these tuna species. This study investigates the statistical relationships between ENSO conditions and equatorial fisheries using various indices and records. The findings suggest that El Nino events have delayed and concurrent positive effects on the catch per unit effort (CPUE) of these tuna species, possibly due to enhanced recruitment and other factors.
FISHERIES OCEANOGRAPHY
(2023)
Article
Environmental Sciences
Jihwan Kim, Hanna Na
Summary: This study investigated the interannual variability of yellowfin and bigeye tuna catches in the southwestern tropical Indian Ocean over 25 years and found that the catch amounts in the northern region are related to temperature, salinity, and current variability. The catch variability in the northern region is more closely related to El Nino-Southern Oscillation.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Fisheries
Cleridy E. Lennert-Cody, Jon Lopez, Mark N. Maunder
Summary: The study developed annual set type classification algorithms for the tropical tuna purse-seine fishery in the eastern Pacific Ocean using random forests. The results showed that different set types can be reliably distinguished based on operational characteristics and catch and bycatch information. The algorithms had low misclassification error rates and could be used to validate set type determinations based on other criteria.
FISHERIES RESEARCH
(2023)
Article
Biodiversity Conservation
Taha Imzilen, Christophe Lett, Emmanuel Chassot, David M. Kaplan
Summary: The study analyzed dFAD trajectories in the Indian Ocean and Atlantic Ocean, finding that prohibiting deployments in specific areas can significantly reduce dFAD beaching events. The riskiest areas for beaching are not necessarily where dFAD deployment is highest, suggesting closures could have minimal impact on fisheries.
BIOLOGICAL CONSERVATION
(2021)
Article
Biodiversity Conservation
Laura Mannocci, Yannick Baidai, Fabien Forget, Mariana Travassos Tolotti, Laurent Dagorn, Manuela Capello
Summary: Research shows that applying machine learning to buoy data can reduce bycatch risk and improve selectivity in one of the largest fisheries worldwide.
BIOLOGICAL CONSERVATION
(2021)
Article
Fisheries
Anandamayee Majumdar, Cleridy E. Lennert-Cody, Mark N. Maunder, Alexandre Aires-da-Silva
Summary: Conditionally autoregressive (CAR) space-time models are widely applicable in capturing spatial association structure through an adjacency matrix. The traditional model has a dependence on adjacency relationships, which may not reflect nonspatial considerations. To address this, a new parametric formulation of the adjacency structure was developed. This method was applied to estimate bigeye tuna catch in the eastern Pacific Ocean, utilizing multiple sources of spatio-temporal data to enhance prediction results. The new formulation outperformed traditional formulations and proved to be robust in sensitivity analysis.
FISHERIES RESEARCH
(2023)
Article
Fisheries
Anildo Nataniel, Jon Lopez, Maria Soto
Summary: This study investigated the environmental preferences and biomass aggregation patterns of tropical tuna from purse seine fishery in the Mozambique Channel (MZC). Using Spanish fishing logbook data, the study found that oceanographic, temporal, and spatial factors have different effects on tuna biomass accumulation in different fishing modes, but there are some commonalities in the area and period of study.
FISHERIES RESEARCH
(2021)
Article
Engineering, Marine
Qinglian Hou, Cheng Zhou, Rong Wan, Junbo Zhang, Feng Xue
Summary: The study presented a tuna fish school recognition system that utilizes feature point extraction and matching. By combining the best feature point algorithms with the k-nearest neighbors algorithm, the system successfully achieves accurate recognition of free-swimming tuna fish schools.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
