Effects of a shark repulsion device on rocky reef fishes: no shocking outcomes

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 408:295-298 (2010) - DOI: https://doi.org/10.3354/meps08591 NOTE Effects of a shark repulsion device on rocky reef fishes: no shocking outcomes A. Broad1, N. Knott1,2, X. Turon3, A. R. Davis1,* 1Institute for Conservation Biology & School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia 2Jervis Bay Marine Park, PO Box 89, Huskisson, New South Wales 2540, Australia 3Centre for Advanced Studies, 17300 Blanes, Girona, Spain *Corresponding author. Email: adavis@uow.edu.au ABSTRACT: Shark repulsion devices (SRDs; e.g. Shark Shield™) use an electric field to deter large and potentially dangerous sharks. The use of these devices is becoming increasingly widespread for a range of recreational activities as well as scientific and commercial diving. We sought to determine if SRDs might modify the behaviour of chondrichthyan and osteichthyan fishes and thereby impact on fish assemblages, as well as potentially bias diver census techniques. To assess the potential impacts of this technology, we attached SRDs to baited remote underwater video (BRUV) units and deployed them on shallow rocky reefs in Jervis Bay Marine Park (New South Wales, Australia). We did not detect any impacts of the SRD on the diversity or relative abundance of shallow-reef fishes. In addition, approach of fishes to the bait did not differ whether the SRDs were on or off. At the smallest spatial scale we investigated, contact with the bait was half as frequent when the SRD was switched on compared to when it was off. Surprisingly, even the cartilaginous species were apparently unaffected by the SRD, with the eastern fiddler ray Trygonorrhina fasciata making contact with the bait several times when SRDs were activated. We contend that the ecological impacts of SRDs at all but the smallest scales are minimal and they are unlikely to introduce bias in assessments of fish assemblages, at least for non-cartilaginous and small cartilaginous species. KEY WORDS: Ampullae of Lorenzini · Baited remote underwater video · Elasmobranch · Electrical pulse · Jervis Bay Marine Park · Sampling bias · Shark-shield · Underwater visual census Full text in pdf format PreviousNextCite this article as: Broad A, Knott N, Turon X, Davis AR (2010) Effects of a shark repulsion device on rocky reef fishes: no shocking outcomes. Mar Ecol Prog Ser 408:295-298. https://doi.org/10.3354/meps08591 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 408. Online publication date: June 03, 2010 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2010 Inter-Research.