title: The aggregation of tuna around floating objects: what could be the underlying social mechanisms?
abstract: Several empirical and theoretical studies have shown how the exploitation of food sources, the choice of resting sites or other types of collective decision-making in heterogeneous environments are facilitated and modulated by social interactions between conspecifics. It is well known that many pelagic fishes live in schools and that this form of gregarious behavior provides advantages in terms of food intake and predator avoidance efficiency. However, the influence of social behavior in the formation of aggregations by tuna under floating objects (FOBs) is poorly understood. In this work, we investigated the collective patterns generated by different theoretical models, which either include or exclude social interactions between conspecifics, in the presence of two aggregation sites. The resulting temporal dynamics and distributions of populations were compared to in situ observations of tuna behavior. Our work suggests that social interactions should be incorporated in aggregative behavior to reproduce the temporal patterns observed in the field at both the individual and the group level, challenging the common vision of tuna aggregations around FOBs. Our study argues for additional data to further demonstrate the role of social behavior in the dynamics of these fish aggregations. Understanding the interplay between environmental and social factors in the associative behavior of fish with FOBs is necessary to assess the consequences of the widespread deployment of artificial FOBs by fishermen.
authors: Unit of Social Ecology, Université Libre de Bruxelles (ULB), Campus de la Plaine, Bd du Triomphe, Bat N0, No. 5, 1050 Brussels, Belgium; UMR 212, Exploited Marine Ecosystems, Institut de Recherche pour le Développement (IRD), Avenue Jean Monnet, 34203 Sète Cedex, France; Institut Français de Recherche pour l'Exploitation de la Mer (Ifremer), Laboratoire de Technologie et Biologie Halieutiques, 8 Rue Toullec, 56100 Lorient, France. Electronic address: Marianne.robert@ifremer.fr.
authors: Marianne
authors: M
authors: Robert
authors: UMR 212, Exploited Marine Ecosystems, Institut de Recherche pour le Développement (IRD), Avenue Jean Monnet, 34203 Sète Cedex, France.
authors: Laurent
authors: L
authors: Dagorn
authors: Unit of Social Ecology, Université Libre de Bruxelles (ULB), Campus de la Plaine, Bd du Triomphe, Bat N0, No. 5, 1050 Brussels, Belgium.
authors: Jean Louis
authors: JL
authors: Deneubourg
mesh_terms: D000818:Animals; D000835:Animals, Wild; D001522:Behavior, Animal; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology*; D008962:Models, Theoretical; D009068:Movement / Q000502:physiology*; D012919:Social Behavior; D014413:Tuna / Q000502:physiology*
keywords: Fish aggregating devices; Models of aggregation; Monte Carlo multi-agents simulations; Social behavior