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We thank Marie-Claire Demers, Rhiannon Kiggins, Mark Fackerell and Simon Rees for assistance with fieldwork. We acknowledge support from JBMP and Booderee National Park staff. We thank Geoff Hurt for assistance and construction of the BRUV units. We thank the 3 anonymous reviewers for their constructive comments. We also thank the Ecological Society of Australia and The Nature Conservancy, Australia, for project support.

Mid-water baited remote underwater video systems (BRUVS) are becoming an increasingly popular tool for examining pelagic fish assemblages in a non-destructive, fisheries independent manner. As the technique is relatively novel, critical methodological questions such as the most appropriate attractant for pelagic fish to mid-water RUVS remain unresolved. In this study, we compared the relative effectiveness of 4 attractant treatments (sight: metallic reflectors, sound: bait fish recordings, scent: pilchards and their combination) on the time of first arrival, total abundance of pelagic fish and the relative abundance of 3 pelagic fish species: Trachurus novaezelandiae, Sarda australis and Seriola lalandi. Recordings were made using mid-water RUVS in the Jervis Bay Marine Park, Australia. RUVS using a combination of all attractants recorded the highest abundances and shortest time of first arrival of pelagic fish. This result was primarily driven by Trachurus novaezelandiae. Although not significant, the abundance of Sarda australis was also greatest on the RUVS with all attractants. In contrast, the type of attractant had no effect on the abundance of Seriola lalandi. Bait, the standard attractant used in BRUVS surveys, was a poor performer for pelagic fish in all instances. We suggest that future studies using this sampling method employ multiple attractants. Disciplines Medicine and Health Sciences | Social and Behavioral Sciences Publication Details Rees, M. J., Knott, N. A., Fenech, G. V. & Davis, A. R. (2015). Rules of attraction: enticing pelagic fish to midwater remote underwater video systems (RUVS). Marine Ecology: Progress Series, 529 213-218. This journal article is available at Research Online: http://ro.uow.edu.au/smhpapers/3002

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 addi- tion, approach of fishes to the bait did not differ whether the SRDs were on or off. At the smallest spa- tial 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 small- est scales are minimal and they are unlikely to introduce bias in assessments of fish assemblages, at least for non-cartilaginous and small cartilaginous species.

In the past decade there has been a rapid increase in the study of the ecological consequences of marine invasions, but we still have data for only a small proportion of established marine invaders. This is exemplified by Port Phillip Bay, Australia, for which we have quantitative data on the impacts of only a handful of the >160 introduced and cryptogenic species present. Some of the most conspicuous of these invaders are the large epibenthic suspension feeders living on soft sediments. In this study, we examined the impact of 2 of the most common epibenthic suspension feeders in Port Phillip Bay, the introduced polychaete Sabella spallanzanii and an introduced solitary ascidian, Styela clava, by manipulating their densities in the field across the range of naturally occurring densities. Because of their physical presence at the sediment–water interface and suspension feeding activities, we predicted varying impacts across different macrofaunal groups (suspension feeders, deposit feeders, recruits and mobile species). These predictions were not supported for either introduced species despite good power. For individual taxa, there was a significant negative relationship between Sabella density and the abundance of lumbrinerid polychaetes and gammarid amphipods, and between Styela density and the abundance of lumbrinerids, tanaids, crustaceans as a group, and the bivalve Laternula rostrata. Nonetheless, these taxa only represent a small proportion of those present, and importantly, the effects generally emerged at Sabella and Styela densities (>1 to 2 ind. m–2) greater than those typically recorded on Port Phillip Bay sediments. Therefore, we suggest that the effects of Sabella and Styela on soft sediment assemblages in Port Phillip Bay are likely to be negligible.