Surveys of fish-habitat associations in the region offshore from James Price Point, Western Australia, using Baited Remote Underwater Video Stations (BRUVS (TM))

Brief description

Baited Remote Underwater Video Stations (BRUVS (TM)) were deployed in coastal waters between Quondong Point and Coulomb Point, to sample demersal and semi-­demersal fishes, sharks, rays and sea snakes. Of the 197 BRUVS (TM) deployed, 154 produced imagery of sufficient quality to classify the benthic substratum, epibenthic cover and to identify and count vertebrates.BRUVS (TM) were deployed below the 5 metre depth contour (lowest astronomical tide) and placed at random within a grid of the entire study area (30x14 km), at spacings not less than 450m apart, to avoid double counting of more mobile fish. Surveys were completed around the neap tides in mid October 2009. Habitats dominated by stony corals were not sampled because they occurred intertidally, or in waters too shallow for access by the survey vessel. Baited Remote Underwater Video Stations (BRUVS (TM)) were deployed to provide baseline estimates of the diversity and relative abundance of demersal and semi-demersal fishes, sharks, rays and sea snakes in the James Price Point coastal area in direct relation to habitat and depth.

Lineage

Maintenance and Update Frequency: asNeeded

Statement: Statement: A BRUVS (TM) consists of a galvanised steel frame onto which a camera housing, bait arm, ballast weights, ropes and floats are attached. A Sony MiniDV tape handicam is used to film through an acrylic port within a PVC underwater housing, pressure-rated to depths of 100m. A flexible bait arm holds a plastic mesh bait bag containing 1kg of minced pilchards (Sardinops sagax neopilchardus) at a distance of approximately 1m in front of the camera lens. BRUVS (TM) frames are ballasted according to the prevailing sea-­state and current conditions to ensure stability on the seabed. An 8mm diameter polypropylene rope with surface floats attached enables the BRUVS (TM) to be deployed and later retrieved from the surface. The scope of the rope length is selected to be approximately twice the water depth.Descriptions of the methods used during BRUVS (TM) surveys can be found in:Cappo MC, Speare PJ and De'ath AG (2004) Comparison of baited remote underwater video stations (BRUVS (TM)) and prawn (shrimp) trawls for assessments of fish biodiversity in inter-reefal areas of the Great Barrier Reef Marine Park. Journal of Experimental Marine Biology and Ecology 302: 123-152.andCappo MC, De'ath AG, Stowar MJ, Johannson C and Doherty PJ (2009) The influence of zoning (closure to fishing) on fish communities of the deep shoals and reef bases of the southern Great Barrier Reef. Part 2 - Development of protocols to improve accuracy in baited video techniques used to detect effects of zoning. MTSRF Research Report No. 38 ISBN 9781921359378. Reef and Rainforest Research Centre and Australian Institute of Marine Science. 44 p.