FN Archimer Export Format PT C TI Mapping tuna occurrence under drifting fish aggregating devices from Fisher’s Echosounder buoys in Indian Ocean BT AF BAIDAI, Yannick DAGORN, Laurent Amande, MJ GAERTNER, Daniel CAPELLO, Manuela AS 1:1,2;2:1;3:2;4:1;5:1; FF 1:;2:;3:;4:;5:; C1 UMR MARBEC (IRD, Ifremer, Université de Montpellier, CNRS), Sète ; France Centre de Recherches Océanologiques (CRO), DRAV, 29, Rue des pêcheurs, BPV 18, Abidjan, Côte d’Ivoire C2 IRD, FRANCE IRD, COTE IVOIRE SI SETE SE IRD UM MARBEC UR https://archimer.ifremer.fr/doc/00592/70454/68576.pdf LA English DT Proceedings paper DE ;Echosounders;drifting fish aggregating devices (FAD);Tropical tunas;Abundance AB Echosounder buoys data obtained from instrumented drifting FADs represent an unprecedented source of information for assessing the spatio-temporal distribution of tropical tuna. Using machine learning algorithms, we transformed acoustic data collected from one of the main echosounder buoys models used by the French purse seine fleet (M3I) into presence/absence of tuna aggregations, enabling the measurement of the amount of inhabited FADs on a given spatiotemporal strata. This paper presents the spatial and temporal distribution of the proportion of drifting fish aggregating devices (DFADs) occupied by tuna aggregations relative to the total number of FADs in the Indian Ocean on a monthly basis, on a 5° grid for year 2016. The perspectives opened up by this new approach in improving estimates of abundance of tropical tuna populations are discussed. PY 2019 CT 21st Working Party on Tropical Tunas (WPTT). 21-26/10/2019, Donostia-San Sebastian, Spain. Meetings documents. IOTC-2019-WPTT21-56_Rev1. 8p. ID 70454 ER EF