scholarly journals Evaluation of a fishing captain's ability to predict species composition, sizes, and quantities of tunas associated with drifting fish-aggregating devices in the eastern Pacific Ocean

2014 ◽  
Vol 71 (7) ◽  
pp. 1774-1780 ◽  
Author(s):  
Daniel W. Fuller ◽  
Kurt M. Schaefer
Keyword(s):  
Pacific Ocean ◽  
Species Composition ◽  
Eastern Pacific ◽  
Purse Seine ◽  
Thunnus Albacares ◽  
Eastern Pacific Ocean ◽  
Mixed Species ◽  
Katsuwonus Pelamis ◽  
Thunnus Obesus ◽  
Fish Aggregating Devices

Abstract Experiments were conducted to evaluate a fishing captain's ability to predict species composition, sizes, and quantities of tunas associated with drifting fish-aggregating devices (FADs), before encirclement with a purse-seine net. Operating in the equatorial eastern Pacific Ocean, during 11 May–23 July 2011, Captain Ricardo Diaz detected small quantities of bigeye (Thunnus obesus) and yellowfin (Thunnus albacares) tunas within large FAD-associated aggregations dominated by skipjack tuna (Katsuwonus pelamis). The captain's predictions were significantly related to the actual total catch and catch by species, but not to size categories by species. His predictions of species composition were most accurate when estimates of bigeye and yellowfin tuna were combined. If purse-seine captains are able to make accurate predictions of the proportion of bigeye and yellowfin tunas present in mixed-species aggregations associated with FADs, managers may wish to consider incentives to fishers to reduce the fishing mortality on those species.

scholarly journals Effects of gear characteristics on the presence of bigeye tuna (Thunnus obesus) in the catches of the purse-seine fishery of the eastern Pacific Ocean

2008 ◽  
Vol 65 (6) ◽  
pp. 970-978 ◽  
Author(s):  
Cleridy E. Lennert-Cody ◽  
Jason J. Roberts ◽  
Richard J. Stephenson
Keyword(s):  
Pacific Ocean ◽  
Eastern Pacific ◽  
Purse Seine ◽  
Bigeye Tuna ◽  
Eastern Pacific Ocean ◽  
Mixed Species ◽  
Thunnus Obesus ◽  
Floating Object ◽  
Floating Objects ◽  
Purse Seine Fishery

Abstract Lennert-Cody, C. E., Roberts, J. J., and Stephenson, R. J. 2008. Effects of gear characteristics on the presence of bigeye tuna (Thunnus obesus) in the catches of the purse-seine fishery of the eastern Pacific Ocean. – ICES Journal of Marine Science, 65: 970–978. Overfishing of bigeye tuna in the eastern Pacific Ocean has motivated a search for a practical means of reducing the catch of bigeye tuna in mixed species aggregations. To explore the effects of gear characteristics on the catch of bigeye tuna, a classification algorithm for the presence/absence of bigeye tuna catch in purse-seine sets on floating objects is developed, using the tree-based method, random forests. Although the location of the set was the strongest determinant of bigeye tuna catch with these data, bigeye tuna in some areas were more likely to be caught on floating objects with greater underwater depths and with deeper purse-seines. Misclassified sets that caught bigeye tuna were concentrated within certain vessels, suggesting the existence of additional vessel effects. Results indicate that fishers may avoid catching bigeye tuna in some areas by changing the depth of the material hanging from the floating object and the actual fishing depth of the purse-seine, or by moving to other fishing areas. Nonetheless, given the complexity of configuring a purse-seine, and the difficulties associated with monitoring compliance with gear regulations, fishery-wide gear restrictions would be problematic.

210Po Activity and Concentrations of Selected Trace Elements (As, Cd, Cu, Hg, Pb, Zn) in the Muscle Tissue of Tunas Thunnus albacares and Katsuwonus pelamis from the Eastern Pacific Ocean

2012 ◽  
Vol 149 (3) ◽  
pp. 371-376 ◽  
Author(s):  
Jorge Ruelas-Inzunza ◽  
Martín Federico Soto-Jiménez ◽  
Ana Carolina Ruiz-Fernández ◽  
Humberto Bojórquez-Leyva ◽  
Hascibe Pérez-Bernal ◽  
...  
Keyword(s):  
Trace Elements ◽  
Pacific Ocean ◽  
Muscle Tissue ◽  
Eastern Pacific ◽  
Thunnus Albacares ◽  
Eastern Pacific Ocean ◽  
Katsuwonus Pelamis ◽  
210Po Activity

scholarly journals Recent purse-seine FAD fishing strategies in the eastern Pacific Ocean: what is the appropriate number of FADs at sea?

2018 ◽  
Vol 75 (5) ◽  
pp. 1748-1757 ◽  
Author(s):  
Cleridy E Lennert-Cody ◽  
Gala Moreno ◽  
Victor Restrepo ◽  
Marlon H Román ◽  
Mark N Maunder
Keyword(s):  
Pacific Ocean ◽  
Ecological Impact ◽  
Eastern Pacific ◽  
Purse Seine ◽  
Eastern Pacific Ocean ◽  
Management Measures ◽  
Fishing Strategies ◽  
Quantitative Analyses ◽  
Reduced Rate ◽  
Fish Aggregating Devices

Abstract Concerns about the ecological impact of recent increases in the use of drifting fish-aggregating devices (FADs) have led to implementation of FAD limits worldwide in purse-seine fisheries targeting tropical tunas. However, quantitative analyses supporting such management measures are needed. Analyses of observer data for purse-seine vessels operating in the eastern Pacific Ocean (EPO) during 2012–2015 were conducted. FAD fishing strategies identified in this analysis were found to vary with distance to the coast. Vessels that operated furthest offshore made a large number of FAD deployments and fished primarily on FADs they deployed themselves. Vessels that operated closest to the coast made the fewest FAD deployments and fished about equally on FADs they deployed themselves and on FADs deployed by other vessels. Independent of the FAD fishing strategy, the estimated relationship between deployments and sets was increasing but nonlinear, with a reduced rate of return beyond about 200 deployments. An analysis of the relationship between deployments and standardized catch per successful set, however, provided some support for the hypothesis that more deployments may allow vessels to optimize fishing efficiency. These results highlight the complexity of EPO FAD fishing strategies and have management implications for limits on FAD usage globally.

Spatial segregation by size of billfishes bycaught by the tuna purse-seine fishery in the Eastern Pacific Ocean

2021 ◽  
Vol 241 ◽  
pp. 106001
Author(s):  
Osman Crespo-Neto ◽  
Eric Díaz-Delgado ◽  
Tatiana A. Acosta-Pachón ◽  
Raúl O. Martínez-Rincón
Keyword(s):  
Pacific Ocean ◽  
Spatial Segregation ◽  
Eastern Pacific ◽  
Purse Seine ◽  
Eastern Pacific Ocean ◽  
Purse Seine Fishery

Size-specific spatiotemporal dynamics of bigeye tuna (Thunnus obesus) caught by the longline fishery in the eastern Pacific Ocean

2021 ◽  
Vol 243 ◽  
pp. 106065
Author(s):  
Keisuke Satoh ◽  
Haikun Xu ◽  
Carolina V. Minte-Vera ◽  
Mark N. Maunder ◽  
Toshihide Kitakado
Keyword(s):  
Pacific Ocean ◽  
Spatiotemporal Dynamics ◽  
Eastern Pacific ◽  
Longline Fishery ◽  
Bigeye Tuna ◽  
Eastern Pacific Ocean ◽  
Thunnus Obesus

scholarly journals KOMPOSISI JENIS DAN DISTRIBUSI UKURAN IKANPELAGIS BESAR HASILTANGKAPANPANCINGULURDI SENDANGBIRU, JAWATIMUR

2017 ◽  
Vol 3 (6) ◽  
pp. 377
Author(s):  
Ria Faizah ◽  
Aisayah Aisayah
Keyword(s):  
Species Composition ◽  
Size Distribution ◽  
Landing Site ◽  
Pelagic Fish ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Bigeye Tuna ◽  
Katsuwonus Pelamis ◽  
Individual Weight ◽  
Thunnus Obesus

Sendang Biru merupakan salah satu tempat pendaratan ikan pelagis besar di Jawa Timur. Penelitian tentang komposisi jenis dan ukuran ikan pelagis besar hasil tangkapan pancing ulur yang didaratkan di PPI Pondok Dadap, Sendang Biru, Jawa Timur, dilakukan pada bulanApril dan Oktober 2010. Hasil penelitian menunjukkan hasil tangkapan pancing ulur didominasi oleh jenis tuna (Thunnus albacares dan Thunnus obesus) 45%, cakalang (Katsuwonus pelamis) sebesar 38 %, dan lainnya (marlin, lemadang, lauro) sebesar 1,7 %. Ikan tuna yang didaratkan terdiri dari jenis yellowfin tuna (Thunnus albacares) dan bigeye tuna (T. obesus) dengan ukuran panjang cagakmasing –masing berkisar antara 40 - 170 cmFL dan 40 - 140 cmFL. Berat individumasing-masing berkisar antara 0.1 - 71 kg dan 0.5 - 43 kg. Sendang Biru is one of big pelagic’s landing site in East Java. Tuna on this research are caught by handline that landing in PPI Pondok Dadap, Sendang Biru, East Java. Research on the species composition and size distribution of big pelagic fish caught by handline were carried out during April and October 2010 at Sendang Biru, East Java. The result showed that Thunnus sp. are the most landed (45%) followed by Katsuwonus pelamis (38 %) and others (Xiphias gladius, Coriphaena sp., Elagatis bipinnulatus) of 1.7 %. The dominant fork lengthof Thunnus albacares and Thunnus obesus ranged from about 40 - 170 cm and 40 – 140 cm. Individual weight ranged between 0.1 - 71 kg and 0.5 - 43 kg respectivelly.

Evaluating fishery impacts: Application to bigeye tuna (Thunnus obesus) in the eastern Pacific Ocean

2009 ◽  
Vol 99 (2) ◽  
pp. 106-111 ◽  
Author(s):  
Sheng-Ping Wang ◽  
Mark N. Maunder ◽  
Alexandre Aires-da-Silva ◽  
William H. Bayliff
Keyword(s):  
Pacific Ocean ◽  
Eastern Pacific ◽  
Bigeye Tuna ◽  
Eastern Pacific Ocean ◽  
Thunnus Obesus
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