Abstract

An emerging tool for the designation of Marine Reserves, Essential Fish Habitat and Effective Juvenile Habitat is the use of acoustic telemetry to interpret habitat connectivity and distribution. The present study investigated acoustic telemetry capabilities with the use of a Vemco V-7 transmitter and VR2/VR2-W receivers at 12 selected sites from a previous tracking study on white grunts (Haemulon plumierii) in La Parguera, southwestern Puerto Rico. Sites reflected location-type: open sand, reef-sand interface, on reef slope, and mixed habitat on reef crest. At each site, 4 transects were performed by guiding a transmitter to simulate fish movement within the 250-m radius of optimal detection range established by Vemco, Ltd.. To elucidate potential presence/absence areas, each GPS-tracking history was combined with a detailed habitat map and the output of Spatial Anaylst application, Viewshed. Using bathymetry as an input, Viewshed focuses on line-of-sight from a given point within a specified range. Data from the range testing show a strong positive correlation between the detections within predicted visible area vs. total detections (r = 0.936), thus proving Viewshed’s accuracy. Correlations were higher in open areas of sand than areas of variable reef structure, where the probability of interference is greater. Technology limitations include environmental parameters, such as current flow and turbidity, properties of sound vs. vision, and behavioral, ecological and social characteristics of tagged species. The combination of these technologies ultimately proved beneficial and may further be investigated at varying temporal and spatial scales for more effective habitat and fisheries management.

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