Chassot Emmanuel, Lucas J., Assan C., Lucas V., Isaac P., Geehan J. (2016). Review of the size-frequency data collected from Seychelles industrial longliners during 2007-2015.
Victoria Mahé : CTOI, 17 p. multigr. (Documents de Réunion ; IOTC-2016-WPDCS12-17-Rev1). Groupe de Travail sur la Collecte des Données et les Statistiques (GTCDS) = Working Party on Data Collection and Statistics (WPDCS), 12., Victoria (SEY), 2016/11/28-30.
Titre du document
Review of the size-frequency data collected from Seychelles industrial longliners during 2007-2015
Année de publication
2016
Type de document
Colloque
Auteurs
Chassot Emmanuel, Lucas J., Assan C., Lucas V., Isaac P., Geehan J.
Source
Victoria Mahé : CTOI, 2016,
17 p. multigr. (Documents de Réunion ; IOTC-2016-WPDCS12-17-Rev1).
Colloque
Groupe de Travail sur la Collecte des Données et les Statistiques (GTCDS) = Working Party on Data Collection and Statistics (WPDCS), 12., Victoria (SEY), 2016/11/28-30
A large set of size data for yellowfin and bigeye tunas has been collected aboard Seychelles industrial longliners since 2007 and carefully checked and managed by the Seychelles Fishing Authority. Analysis of the data at the scale of the fishing operation shows that size frequency data collected at sea by fishermen are consistent with logbook information in several vessels while some data appear to be spurious. We also show that changes in spatial distribution of the longline fleet in relation with piracy threat might explain some changes in average weight in the catch observed in the early 2010s within the large areas used for assessing the status of the stocks. Future work will aim (i) to improve data collection from the identification of vessels that appear to report size data of poor quality and (ii) to select the good size data sets to be used in the future assessments of Indian Ocean yellowfin and bigeye tuna. The availability of operational data is key to determine the causes of discrepancy between data sources of tuna size and eventually improve the overall quality of management advice.
Plan de classement
Appliquées à la pêche [040INFSTA01]
;
Stocks [040PECHE03]
Descripteurs
NAVIRE DE PECHE ; PECHE THONIERE ; COLLECTE DE DONNEES ; ANALYSE DE DONNEES ; ESTIMATION DE STOCK ; STRUCTURE DE POPULATION
