Search

Individual fish movement patterns and behaviors influence population-level traits, and are important for understanding their ecology and evolution. Understanding these behaviors is key for managing and conserving migratory animal populations, including Atlantic tarpon (Megalops atlanticus), that support an economically important recreational fishery. Using acoustic telemetry, we tracked individual movement patterns of M. atlanticus inhabiting the eastern Gulf of Mexico and the southeast coast of the US over successive years. Net-squared displacement models revealed considerable individual-level variation in movement patterns with high individual-level repeatability in the timing of migrations and migratory pathways. Although distinct migratory subgroups existed, M. atlanticus generally migrate northward in the spring and summer to putative foraging grounds and remain in these areas for, on average, four months and then migrate southward in the fall. Subadult M. atlanticus exhibited similar migratory patterns as adults, while large juveniles exhibited either resident or nomadic behaviors. For migratory individuals, fish size did not influence movement patterns. Given that distinct migratory subgroups seasonally mixed in southern Florida for spawning activity, our study indicates that M. atlanticus along the eastern Gulf of Mexico and southeastern coast of the US should be considered a single interconnected stock. With that in mind, using M. atlanticus angler and guide knowledge, we assessed the vulnerability of M. atlanticus to potential threats across their range and along migratory pathways. Collectively, the far-ranging nature of M. atlanticus and their diversity in movement patterns highlights the need for more uniform and cohesive management and conservation efforts. [ABSTRACT FROM AUTHOR]

Intertidal and subtidal zones consist of heterogeneous habitats and dynamic environmental conditions, providing diverse options for fish to take advantage of marine resources. We explored how various environmental factors affected habitat use of an ecologically and economically important tropical marine fish, bonefish (Albula vulpes), on a fringing reef flat in Culebra, Puerto Rico, using a fine-scale acoustic telemetry positioning system. Machine learning algorithms and Bayesian inference via integrated nested Laplace approximation indicated diel period was the most important predictor of bonefish habitat use; bonefish occupied seagrass and mixed bottom (seagrass, macroalgae, sand) habitats most often at night, a deep-water soft sediment lagoon during the day, and infrequently used a shallow coral rubble reef crest. Zero-truncated (presence only) positioning frequency revealed more constrained utilization distributions during daytime and periods of higher water temperatures. Bonefish occupancy was highest in seagrass and mixed bottom habitats at lower water temperatures, and declined rapidly throughout the flat above 30 °C, which is consistent with temperature-mediated physiological constraints on performance (i.e. collapse of aerobic scope). Other factors including lunar phase, tidal state, and tide height had limited influence on bonefish habitat use. Building on a body of research, we propose several drivers of bonefish habitat use patterns amongst the diverse regions and habitats occupied, including predation risk, angling pressure, tidal variations, and temperature-related physiological performance. Our results emphasise the importance of conserving important seagrass foraging habitat through management and restoration., Author(s): Jacob W. Brownscombe [sup.1] , Lucas P. Griffin [sup.2] , Tyler O. Gagne [sup.2] , Christopher R. Haak [sup.2] , Steven J. Cooke [sup.1] , John T. Finn [sup.2] [...]