Chassot Emmanuel, Assan C., Esparon J., Tirant A., Delgado de Molina A., Dewals Patrice, Augustin E., Bodin Nathalie. (2016). Length-weight relationships for tropical tunas caught with purse seine in the Indian Ocean : update and lessons learned.
Victoria Mahé : CTOI, 11 p. multigr. (Documents d'Information ; IOTC-2016-WPDCS12-INF05). 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
Length-weight relationships for tropical tunas caught with purse seine in the Indian Ocean : update and lessons learned
Année de publication
2016
Type de document
Colloque
Auteurs
Chassot Emmanuel, Assan C., Esparon J., Tirant A., Delgado de Molina A., Dewals Patrice, Augustin E., Bodin Nathalie
Source
Victoria Mahé : CTOI, 2016,
11 p. multigr. (Documents d'Information ; IOTC-2016-WPDCS12-INF05).
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
Morphometric data for tropical tunas caught with purse seine have been collected in the Indian Ocean over the last decades through routine sampling at processing factories and research projects. We estimate the parameters of allometric relationships between fork length (cm) and total weight (kg) for bigeye (Thunnus obesus), skipjack (Katsuwonus pelamis), and yellowfin tuna (Thunnus albacares) caught with purse seine in the Indian Ocean. We show that relationships currently used in the IOTC underestimate weights at length for bigeye and skipjack with potential consequences for the estimates of purse seine catch and other datasets derived from fish numbers and size data. We question the use of gear-specific length-weight relationships for tropical tunas. We recommend to carefully and systematically collect morphometric data required for conversion factors and relationships and made them available to the IOTC Secretariat as they are key in data processing and can eventually affect the monitoring of the status of tuna and tuna-like stocks in the Indian Ocean.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020]
;
Ressources halieutiques [040]
