Behavior of dolphinfish (Coryphaena hippurus) around drifting FADs as observed from automated acoustic receivers
|Other titles||Comportement des dorades coryphènes (Coryphaena hippurus) autour des DCP dérivants, observé à l'aide de marques acoustiques et de stations d'écoute|
|Author(s)||Taquet Marc1, Dagorn L2, Gaertner J3, Girard C2, Aumerruddy R4, Sancho G5, Itano D6|
|Affiliation(s)||1 : IFREMER, CRH HMT, F-34203 Sete, France.
2 : Inst Rech Dev, CRH, F-34203 Sete, France.
3 : Ctr Oceanol Marseille, LMGEM, CNRS, UMR 6117, F-13007 Marseille, France.
4 : Seychelles Fishing Author, Victoria, Maha, Seychelles.
5 : Coll Charleston, Grice Marine Lab, Charleston, SC 29412 USA.
6 : Univ Hawaii, JIMAR, Pelag Fisheries Res Program, Honolulu, HI 96822 USA.
|Source||Aquatic Living Resources (0990-7440) (EDP Sciences), 2007-10 , Vol. 20 , N. 4 , P. 323-330|
|WOS© Times Cited||24|
|Keyword(s)||Indian Ocean, Meeting point, Ecological trap, Behavior of fish, Ultrasonic telemetry, Acoustic tagging, FAD, Dolphinfish|
|Abstract||To study the behavior of dolphinfish (Coryphaena hippurus) around drifting Fish Aggregating Devices (FADs), we tagged individuals with long-lived, coded sonic transmitters and attached automated sonic receivers to drifting FADs in two regions of the Western Indian Ocean. Among the three tagging methods used in this study (surgery, external hooks, underwater bait without capture), the latest resulted in residence times significantly shorter than the other ones, likely due to regurgitation. Dolphinfish tagged with the two other methods usually stayed several days associated to FADs (Kaplan-Meier survival analysis 5.09 days, mean 6.25 days, SD 4.39 days, maximum 15.26 days), drifting with them. There was no significant difference in the residence times of dolphinfish in equatorial and tropical areas. While associated to FADs, dolphinfish spent most of their time close to floating object (< 365 m). The total time spent away from FADs was low (median 8%), and likely corresponded to making feeding excursions. Dolphinfish did not form a single school while associated to a given FADs, but formed multiple small schools. FADs are likely to be sites with exchanges of individuals between schools. These results are discussed in regards to the possibility of FADs acting as ecological traps and the validity of meeting-point hypotheses as an explanation for fish aggregations under floating objects.|