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| Tolotti, Mariana Travassos; Forget, Fabien; Capello, Manuela; Filmalter, John David; Hutchinson, Melanie; Itano, David; Holland, Kim; Dagorn, Laurent. |
| Several pelagic fish species are known to regularly associate with floating objects in the open ocean, including commercially valuable species. The tuna purse seine industry takes advantage of this associative behavior and has been increasingly deploying free-drifting man-made floating objects, also known as fish aggregating devices (FADs). Using passive acoustic telemetry, this study describes the associative dynamics of the main targeted tropical tuna species (Thunnus albacares, T. obesus and Katsuwonus pelamis), as well as three major bycatch species, silky shark (Carcharhinus falciformis), rainbow runner (Elagatis bipinnulata) and oceanic triggerfish (Canthidermis maculata). Short-term excursions away from the FADs were frequently performed by all tuna... |
| Tipo: Text |
Palavras-chave: Behavior; Acoustic telemetry; Residence time; Floating objects; Pelagic fish; Tropical tuna. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72077/71042.pdf |
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| Pérez, Geraldine; Dagorn, Laurent; Deneubourg, Jean-louis; Forget, Fabien; Filmalter, John D.; Holland, Kim; Itano, David; Adam, Shiham; Jauharee, Riyaz; Beeharry, Sunil P.; Capello, Manuela. |
| Background Aggregation sites represent important sources of environmental heterogeneity and can modify the movement behavior of animals. When these sites are artificially established through anthropogenic actions, the consequent alterations to animal movements may impact their ecology with potential implications for their fitness. Floating objects represent important sources of habitat heterogeneity for tropical tunas, beneath which these species naturally aggregate in large numbers. Man-made floating objects, called Fish Aggregating Devices (FAD), are used by fishers on a massive scale to facilitate fishing operations. In addition to the direct impacts that fishing with FADs has on tuna populations, assessing the effects of increasing the numbers of FADs... |
| Tipo: Text |
Palavras-chave: Acoustic tagging; Associative behavior; Density of floating objects; Movement behavior; Tropical tuna. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77137/78454.pdf |
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| Walker, Emily; Rivoirard, Jacques; Gaspar, Philippe; Bez, Nicolas. |
| In the open ocean, movements of migratory fish populations are typically surveyed using tagging methods that are subject to low sample sizes for archive tags, except for a few notable examples, and poor temporal resolution for conventional tags. Alternatively, one can infer patterns of movement of migratory fish by tracking movements of their predators, i.e., fishing vessels, whose navigational systems (e.g., GPS) provide accurate and frequent VMS (vessel monitoring system) records of movement in pursuit of prey. In this paper, we develop a state-space model that infers the foraging activities of fishing vessels from their tracks. Second, we link foraging activities to probabilities of tuna presence. Finally, using multivariate geostatistical interpolation... |
| Tipo: Text |
Palavras-chave: GPS; Multivariate geostatistics; Presence index; Spatiotemporal distribution; Trajectometry; Tropical tuna; Vessel monitoring system (VMS). |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00610/72249/71048.pdf |
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