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| Taquet, Coralie; Taquet, Marc; Dempster, T; Soria, M; Ciccione, S; Roos, David; Dagorn, L. |
| We studied the foraging rhythms of green sea turtles Chelonia mydas on the seagrass beds of N'Gouja Bay, Mayotte Island (Comoros Archipelago) with acoustic transmitters and moored listening stations. We monitored 8 tagged turtles (4 probable males, 3 probable females and 1 immature), from 70 to 109 cm curved carapace length (CCL), for durations ranging from 5 to 92 d. The turtles exhibited a regular diel pattern: they foraged mainly during the day (on average 87% of seagrass detections were between 06:00 and 18:00 h) and rested on the inner reef slope during the night. Night time feeding activities were observed on the seagrass bed when the night light was high. The presence of turtles on the seagrass bed at night was significantly correlated with a night... |
| Tipo: Text |
Palavras-chave: Foraging rhythm; Listening station; Acoustic transmitter; Green sea turtle; Mayotte; Southwestern Indian Ocean; Chelonia mydas. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-3616.pdf |
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| Taquet, Marc; Sancho, G; Dagorn, L; Gaertner, J; Itano, D; Aumeeruddy, R; Wendling, B; Peignon, C. |
| We adapted a visual census method, mainly used in demersal and reef fish studies, to characterize fish communities associated to drifting fish aggregating devices (FADs) in the Western Indian Ocean. Drifting FAD associated fishes from both equatorial (Seychelles) and tropical waters (Reunion Island) were examined by divers. A total of 32 species (belonging to 16 families) were observed associated with drifting FADs in equatorial waters, and 24 species (14 families) were found around FADs in tropical waters. Twenty species were found in both regions. The highest number of species observed at a single FAD was 18 (12 +/- 2, mean +/- SD) in equatorial and 13 (10 +/- 3) in tropical waters, not counting circumnatant species loosely associated with the FAD. Some... |
| Tipo: Text |
Palavras-chave: Indian Ocean; Reunion Island; Seychelles; Fish aggregations; Visual census; Drifting FAD; Pelagic fishes. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3734.pdf |
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| Dagorn, L; Pincock, D; Girard, C; Holland, K; Taquet, Marc; Sancho, G; Itano, D; Aumeeruddy, R. |
| Automated acoustic receivers are now widely used by biologists to study the behavior of fish. However, currently available acoustic receivers require physical recovery of the units to download stored data. Such operation is often difficult in remote study areas like in the open ocean. We present a new satellite-linked acoustic receiver (Vemco VR3-Argos) that allows downloading data through a satellite uplink (Argos). The VR3-Argos can last up to one year, sending GPS positions and tag data at regular time intervals. We illustrate the advantages of this new technology with tagging data from 121 fish of seven species (yellowfin tuna, bigeye tuna, skipjack tuna, wahoo, dolphinfish, silky shark and oceanic triggerfish) caught and released around drifting fish... |
| Tipo: Text |
Palavras-chave: Pelagic fish; Tuna; Fish telemetry; Acoustic receiver; FAD. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3731.pdf |
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| Taquet, Marc; Sancho, G; Dagorn, L; Gaertner, J; Itano, D; Aumeeruddy, R; Wendling, B; Peignon, C. |
| We adapted a visual census method, mainly used in demersal and reef fish studies, to characterize fish communities associated to drifting fish aggregating devices (FADs) in the Western Indian Ocean. Drifting FAD associated fishes from both equatorial (Seychelles) and tropical waters (Reunion Island) were examined by divers. A total of 32 species (belonging to 16 families) were observed associated with drifting FADs in equatorial waters, and 24 species (14 families) were found around FADs in tropical waters. Twenty species were found in both regions. The highest number of species observed at a single FAD was 18 (12 +/- 2, mean +/- SD) in equatorial and 13 (10 +/- 3) in tropical waters, not counting circumnatant species loosely associated with the FAD. Some... |
| Tipo: Text |
Palavras-chave: Indian Ocean; Reunion Island; Seychelles; Fish aggregations; Visual census; Drifting FAD; Pelagic fishes. |
| Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00602/71370/69818.pdf |
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| Gaertner, J; Taquet, Marc; Dagorn, L; Merigot, B; Aumeeruddy, R; Sancho, G; Itano, D. |
| This study provides a baseline measure of pelagic fish species diversity around fish aggregating devices (FADs) in the Western Indian Ocean. Using data from visual censuses made by SCUBA divers around drifting FADs we (1) analysed 11 diversity indices describing 4 main components of pelagic diversity: number of species, evenness, taxonomic diversity and rarity and (2) discussed the viability of using visual censuses around FADs to monitor temporal and spatial changes in diversity patterns of pelagic fishes in the future. Our results not only show that a single index, such as species richness or the Shannon-Wiener index, cannot provide a complete description of pelagic fish diversity around FADs, but also that some components of diversity appear to be... |
| Tipo: Text |
Palavras-chave: Indian Ocean; Drifting FADs; Diversity; Pelagic fishes. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4674.pdf |
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| Taquet, Marc; Dagorn, L; Gaertner, J; Girard, C; Aumerruddy, R; Sancho, G; Itano, D. |
| 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... |
| Tipo: Text |
Palavras-chave: Indian Ocean; Meeting point; Ecological trap; Behavior of fish; Ultrasonic telemetry; Acoustic tagging; FAD; Dolphinfish. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3733.pdf |
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