Improved version of the Tropical Tuna Treatment process: new perspectives for catch estimates of tropical purse seine fishery. Catches in the Indian Ocean
|Author(s)||Duparc Antoine1, Depetris Mathieu1, Cauquil Pascal2, Floch L1, Lebranchu Julien1|
|Affiliation(s)||1 : MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Sète, France
2 : MARBEC, Univ Montpellier, CNRS, Ifremer, IRD, Abidjan, Côte d’Ivoire
|Meeting||WPTT22 - 22e Groupe de Travail sur les Thons Tropicaux : réunion d'evaluation. 19-23 octobre 2020, Online|
|Source||WPTT22 - 22e Groupe de Travail sur les Thons Tropicaux : réunion d'evaluation. 19-23 octobre 2020, Online. IOTC-2020-WPTT22(AS)-13_Rev1, 21p.|
|Keyword(s)||yellowfin, Thunnus albacore, bigeye, Thunnus obesus, skipjack, Katsuwonus pelamis, T3 methodology|
The Tropical Tuna Treatment is a process created at the end of the 90s by EU scientists to estimate catch of the tropical tuna purse seine fishery, for which logbook declarations were known biased. His main purpose is to provide the best estimations for nominal catch and catch effort spatially represented, to the RFMOs. However, the evolution of fishing practices and the extension of the fishing grounds have challenged the T3 methodology in some parts of it processing. Thus, the used of too large spatio-temporal sampling strata was specifically pointed out as the major cause of biases in the catch estimated. This paper presents the new methodology developed to fix this issue and implications on the output estimations compared to the previous version and logbook declarations. Finally, future improvements were discussed.