Using acoustic telemetry to assess patterns in the seasonal residency of the Atlantic stingray Dasyatis sabina

Abstract

The Atlantic stingray Dasyatis sabina is found along the Atlantic and Gulf coasts of the United States. It consumes commercially important shrimp and crabs, and its diet overlaps with recreationally valuable red drum Sciaenops ocellatus and pompano Trachinotus spp. Despite the potential economic impact of this species, it is unclear whether the Atlantic stingray is present year-round or only seasonally in coastal habitats. The objective of this study was to assess the seasonal residency patterns of Atlantic stingrays in two creek systems in the Savannah River estuary. Forty stingrays were tracked using acoustic telemetry, and a seasonal residence index was calculated for each individual. Atlantic stingrays were present year-round in the Savannah River estuary, as 15 % (n = 6) of the tagged rays remained in the study areas throughout the year. This is the northernmost region where this species has been documented to be present all year. Of the 85 % (n = 34) of the rays that migrated during winter, 38 % (n = 13) of those were detected within the estuary less than 20 km away. Had trawls or mark-recapture been used instead, the few animals remaining in the creek systems and/or those that migrated may not have been collected. Acoustic telemetry is a more accurate means of studying the residency of fishes than periodic sampling that requires capture, and researchers should consider incorporating this technology in future studies about fish-environment interactions. Underestimating the presence of a species could result in miscalculation of its economic and ecological impact and, by extension, result in the implementation of ineffective or even detrimental management strategies.