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Effective conservation and management of highly migratory marine species relies on adequate characterization of focal habitat areas that often vary across seasons (Federal Register, 2017; Kohler and Turner, 2019). The [...]

Basic distribution and movements of elasmobranch species, particularly mesopredatory rays, remain relatively unknown. This is especially true for the whitespotted eagle ray (Aetobatus narinari), a protected species in Florida with poorly described migratory and habitat use patterns. Passive acoustic telemetry was used to reveal multi-scale spatial patterns of A. narinari in Florida waters. Between 2016 and 2018, 54 rays were fitted with acoustic transmitters and tracked via collaborative telemetry networks. Movement patterns between the Atlantic and Gulf coast individuals were distinct; a majority of Gulf coast tagged A. narinari exhibited migratory or transient behaviors while most Atlantic coast tagged individuals remained resident in the Indian River Lagoon (IRL). On both coastlines, water temperatures during times when A. narinari were present were significantly warmer (mean = 27.8 °C) compared to temperatures when A. narinari were absent (mean = 24.9 °C), suggesting temperature may be a major abiotic factor influencing migration patterns. Ontogenetic shifts in habitat use were evident along the Atlantic coast in the IRL, but not along the Gulf coast. Immature rays spent significantly more time (mean = 91.5%) inside the IRL compared to mature counterparts (mean = 60.2%). This is the first multiyear study to examine large-scale movements of A. narinari in U.S. waters and results may be important for adaptive management strategies throughout this species' range. Importantly, our work suggests potential sub-population structuring of A. narinari may be occurring more than previously considered within Florida, which has significant conservation implications for this species., Author(s): Breanna C. DeGroot [sup.1] , Kim Bassos-Hull [sup.2] [sup.3] , Krystan A. Wilkinson [sup.2] [sup.3] , Susan Lowerre-Barbieri [sup.4] [sup.5] , Gregg R. Poulakis [sup.6] , Matthew J. Ajemian [...]

Coastal marine fishes that form spawning aggregations most commonly exhibit a two-point movement pattern, with locations separated by migration: home range to spawning aggregation site and return to home range. However, the bonefish, Albula vulpes, partakes in a unique three-point spawning migration. Bonefish migrate up to 80 km from shallow water home flats to form nearshore pre-spawning aggregations (PSA) before moving offshore to spawn. Although these broad patterns have previously been documented, details of the offshore spawning-associated diving behavior have yet to be rigorously examined. Using active acoustic telemetry and sonar data in 2019 in Abaco, The Bahamas, we provide a complete account of bonefish offshore spawning movements and novel deep diving behavior to 137.9 m. Bonefish were continuously observed at depths [greater than or equal to] 100 m for 2 h; a time period that included multiple depth changes and culminated in a spawning ascent to 67.3 m at 0.57 m s.sup.-1. These new data on bonefish offshore movements and deep dives, coupled with CTD data, suggest that bonefish actively spawn at pycnoclines and thermoclines. Two previous tracking attempts (2013, 2018) at this location reflect spatiotemporal plasticity in spawning, a behavior counter to other aggregation forming fishes. This is the first detailed documentation of such deep spawning for a shallow water coastal fish species. The ecological motivation for diving to the deepest depths remains speculative. Future work must examine the dynamic relationship between bonefish diving behavior, spawning site selection, and oceanographic features., Author(s): Steven M. Lombardo [sup.1] , Aaron J. Adams [sup.1] [sup.2] , Andy J. Danylchuk [sup.3] , Cameron A. Luck [sup.1] [sup.4] , Matthew J. Ajemian [sup.1] Author Affiliations: (1) [...]