Estimates of incidental mortality of dolphins in the purse-seine fishery for tunas in the eastern Pacific ocean in 1990
Hall, M.A.; Boyer, S.D. (1992). Estimates of incidental mortality of dolphins in the purse-seine fishery for tunas in the eastern Pacific ocean in 1990. Rep. Int. Whal. Commn. 42: 529-531
In: Report of the International Whaling Commission. International Whaling Commission: Cambridge. ISSN 0143-8700, meer
|
| Trefwoorden |
By catch
Fisheries > Finfish fisheries > Tuna fisheries
IE, East Pacific
Population functions > Mortality
Purse seining
Cetacea [WoRMS]
Pacific Ocean [Marine Regions]
Marien/Kust |
| Abstract |
Estimates of incidental dolphin mortality in the eastern Pacific tuna purse-seine fishery in 1990 are presented. A total of 291 trips, or 48.8% of the total number of trips made in 1990 by the international fleet (vessels with flags of Colombia, Costal Rica, Ecuador, Honduras, Mexico, Panama, Peru, USA, Vanuatu and Venezuela) were sampled, 246 by scientific technicians of the Inter-American Tropical Tuna Commission, and 45 (all US vessels) by observers of the US National Marine Fisheries Service. Ratio estimates based on mortality-per-set (MPS) and mortality-per-ton (MPT) ratios yielded total mortality estimates for the international fleet of 52,531 (SE:3,050) and 55,892 (SE:3,143) dolphins, respectively, a decrease of 45% and 46% from the corresponding 1989 values. Most of the decline is due to improving fleet performance, resulting in reduced MPS and MPT ratios (36% and 38% lower than in 1989, respectively); the rest is due mainly to a reduction in the number of sets of dolphin-associated tuna made by US vessels, many of which have left the eastern Pacific. |
|
