Application of telemetry and stable isotope analyses to inform the resource ecology and management of a marine fish

Abstract

1. Animal movement and resource use are essential considerations for effective environmental management, but they are challenging to quantify in expansive natural ecosystems such as oceans.2. We used a novel combination of fish tracking with expansive acoustic telemetry networks, stable isotope analysis and integrated modelling techniques to characterize the spatial and trophic ecology of a marine fish species, permitTrachinotus falcatus, and to address specific resource management needs in the Florida Keys. Tracking-based movement patterns indicated that permit remained primarilywithin the designated fisheries management unit (92% of individuals), but they moved frequently among distinct habitat types and fisheries. Movement metrics from 109 individuals were integrated into Bayesian isotope mixing models, revealing variable reliance on seagrass-versus offshore/pelagic-based energy channels amongst individuals. Variance was driven mainly by fish habitat use and home range size (km 2 ).4. A telemetry-based regional isoscape, informed by individual-level estimates of resource use (% seagrass reliance; median = 70%, 29%-100% range), illustrated connectivity among habitats and fisheries. Specifically, seagrass flats were highly connected with the Florida reef tract, with frequent movements between these habitat types and a high reliance on seagrass-based prey. There was a distinction between these fish and those occupying artificial reefs, with the latter showing high use of pelagic/offshore (i.e. planktonic) energy channels. Synthesis and applications.This study used a novel combination of telemetry, stable isotope analysis and integrated modelling techniques to identify two distinct ecotypes of a nearshore fish species, permit, in the Florida Keys. Of the two ecotypes, nearshore Florida Keys permit support multiple valuable fisheries; for these fish management should prioritize conservation of seagrass flats as | 1111

Tracking the migration and distribution of Caspian Kutum (Rutilus kutum, Kamenskii, 1901) along the southern coastline of the Caspian Sea based on stable isotope analysis

“…Using Bayesian stable isotope, mixing models provided valuable insights into permit ecology and conservation (Brownscombe et al, 2022). Quinzán et al (2016) studied the influence of the environment on the migration pattern of Atlantic pomfret ( Brama brama ) in North‐eastern Atlantic waters; results show the key factor of this species' migration is a strong influence of temperature at 200 m depth along with the upwelling in the Galician (NW Iberian) waters.…”

A participatory climate vulnerability assessment for recreational tidal flats fisheries in Belize and The Bahamas

“…Stable isotope analyses indicate that permit may rely heavily on seagrass beds for foraging (Brownscombe et al, 2022). Permit remain within a home range of 100 km but move frequently among distinct habitat types within this area (Brownscombe et al, 2022), indicating some potential for redistribution by adults under unfavorable climate conditions.…”

“…Juvenile permit are found in both estuary and open coastal sandy beach habitats (Adams and Blewett, 2004;Andrades et al, 2012), whereas adults move between shallow flat sandy areas (< 3 m) to forage and deeper reef areas (15-40 m) to spawn (Brownscombe et al, 2020). Stable isotope analyses indicate that permit may rely heavily on seagrass beds for foraging (Brownscombe et al, 2022). Permit remain within a home range of 100 km but move frequently among distinct habitat types within this area (Brownscombe et al, 2022), indicating some potential for redistribution by adults under unfavorable climate conditions.…”

What acoustic telemetry can and can’t tell us about fish biology

“…The true strength of network analyses is that they offer a scalable method with which to quantify linkages, measure relative centrality or importance of receivers, explore connectivity and determine the extent to which landscape (structural) and behaviour (functional) processes facilitate or impede movement between habitat patches or resources (Baguette & Van Dyck, 2007;Bélisle, 2005). Indeed coupling movement networks with Stable Isotope Analyses (SIA) has led to important and novel discoveries around energy landscapes, for example, the classification of permit (Trachinotus falcatus) into two distinct ecotypes within the Florida Keys, US; one, with a heavy reliance on movements between the Florida reef tract and seagrass beds and their associated prey, and a second that primarily occupy artificial reefs relying almost exclusively on pelagic prey, with clear implications for the management of the fishery (Brownscombe et al, 2022).…”