Catch trend of bigeye tuna Thunnus obesus by purse seine using fish aggregating devices, by flag states and area of operation in tropical regions of the Western and Central Pacific Ocean

Abstract Bigeye tuna (Thunnus obesus) is an important commercial fish species, which aggregates around fish aggregating devices (FADs) together with other tropical tuna species. Acoustics is the main technology used by fishers and scientists for the location and quantification of tunas at FADs. However, currently it is not possible to reliably discriminate between the different tropical tuna species that are found together at FADs using acoustic methods, which hampers the development of selective fishing needed to preserve some of the tropical tuna species for which overfishing is occurring. One of the prerequisites for species discrimination is to know the target strength (TS) of each species at different frequencies. This paper measures in situ TS values and explores the frequency response of bigeye tuna at FADs in the central Pacific Ocean using three different acoustic frequencies. For the range of body length caught (40–100 cm), the obtained b20 values were −65, −66, and −72 dB for 38, 120, and 200 kHz, respectively. The decreasing frequency response pattern obtained for this swimbladder bearing species contrasts with the opposite pattern previously observed for skipjack tuna (bladder-less), the most abundant tuna species found at FADs, hence allowing the potential for discrimination between the two species.

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Recreational billfish catches and gamefishing facilities of Pacific Island nations in the Western and Central Pacific Ocean

Marine and Freshwater Research ◽

10.1071/mf01260 ◽

2003 ◽

Vol 54 (4) ◽

pp. 463 ◽

Cited By ~ 7

Author(s):

Wade Whitelaw

Keyword(s):

Pacific Ocean ◽

Purse Seine ◽

Pacific Island ◽

Central Pacific ◽

Central Pacific Ocean ◽

Tax Relief ◽

The Pacific ◽

Pacific Island Nations ◽

Subsistence Fishing ◽

Pacific Community

Gamefishing is a developing industry for many of the Pacific Island nations, with a number of countries encouraging the industry with tax relief and tourism promotion. This paper was prepared to provide a preliminary appraisal of gamefish facilities and recreational billfish catches of Pacific Island countries in the Western and Central Pacific Ocean. The level of development of gamefishing varies among Pacific Island nations, with fishers of some countries only carrying out subsistence fishing (including billfish), whereas others have a well-developed gamefishing infrastructure. The gamefish facilities of each country are described, including charter operations, number of private vessels and berthing facilities. Estimates of recreationally caught billfish are also provided for each Pacific Island nation. These estimates have been facilitated by the development of a gamefish catch and effort database by the Secretariat of the Pacific Community. Presently, an estimated 1050 metric tonnes of marlin are caught by gamefishing in the Western and Central Pacific Ocean, which compares with an estimate of around 18 000 metric tonnes caught by commercial longline and purse seine vessels.

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Marine pollution originating from purse seine and longline fishing vessel operations in the Western and Central Pacific Ocean, 2003–2015

AMBIO ◽

10.1007/s13280-016-0811-8 ◽

2016 ◽

Vol 46 (2) ◽

pp. 190-200 ◽

Cited By ~ 9

Author(s):

Kelsey Richardson ◽

David Haynes ◽

Anthony Talouli ◽

Michael Donoghue

Keyword(s):

Pacific Ocean ◽

Marine Pollution ◽

Purse Seine ◽

Fishing Vessel ◽

Central Pacific ◽

Central Pacific Ocean

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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 ◽

10.1093/icesjms/fsn075 ◽

2008 ◽

Vol 65 (6) ◽

pp. 970-978 ◽

Cited By ~ 15

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.

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