Marine Evening January 2015 - BRUV's at Dyer Island

January 17, 2015 by dyertrust

Learning more about our inshore fish through Baited Remote Underwater Video Systems.

Marine Dynamics and the Dyer Island Conservation Trust hosted another very successful and informative Marine Evening at the Great White House in Kleinbaai on Tuesday, 27th January 2015.

Guest speaker Leslie Roberson, originally from Seatlle in the USA received her B.A. in Environmental Science from Yale University in 2011. In 2014 she completed her Masters in Applied Marine Science at the University of Cape Town.

She has worked with sea turtle conservation in the Caribbean, sedimentation in the U.S. Virgin Islands, coral resilience in Honduras, and traditional fisheries in Ghana.

For her Masters Thesis, she used underwater video to complete the first survey of reef fish in Bettys Bay Marine Protected Area (MPA).

Leslie explained to the audience why BRU work is so important: The lack of a cheap, yet costeffective and broad--?spectrum fish monitoring technique has delayed surveys and fish monitoring in marine protected areas (MPAs) and other areas of conservation interest in South Africa. Even when surveys are collected, the data is often not used to its full potential due to a lack of scientific and technical expertise and a lack of sufficient training of personnel.

Leslie explaining to the audience what a BRUV System looks like and how it is deployed

Previous surveys have employed underwater visual census and capture survey techniques. The detection power, environmental impact and financial sustainability of these methods have limited their implementation, especially in the cold Benguela upwelling--? driven ecosystems on South Africas west coast. The baited remote underwater video system (BRUVs) has been tested as a standard, non--?extractive methodology that can be applied throughout South Africas near--?shore marine habitat areas.

BRUV surveys have been performed in both protected and exploited areas in South Africa, including False Bay, Bettys Bay, Stilbaai and Tsitsikamma. The standard BRUVs provide data on habitat, species diversity and abundance. The stereo--?BRUVs variation can give estimates of fish length. While fish length is a useful metric because it can be converted to fish size structure data, the stereo--?BRUVs require more complicated equipment for the deployment and additional software and time for the analysis of the length data. Therefore, the single camera BRUVs are more practical as a standard survey tool across South Africa.

The BRUV system operates by lowering a camera rig to the sea floor and recording approximately one hour of footage for later analysis of the habitat, number and behavior of the species within view. Deployments can be made simultaneously in groups of up to four rigs. Cameras are deployed at least 150 m apart to maintain sample independence.

This will be the first study of its nature around Dyer Island.

Staff from both the Dyer Island Conservation Trust as well as CapeNature will be trained to utilize BRUV systems during this study and in the long term this will become a monitoring project for the Dyer Island Conservation Trust and the International Marine Volunteers in the Greater Dyer Island Region.

We thank one and all who attended this evening, it was by far one the most interactive audiences at our Marine evenings.

All visitors was also reminded that the African Penguin and Seabird Sanctuary is nearing completion, and that anyone is welcome to stop by to see the progress on site there will not always be people on had to show them around, but with the sponsorship of the horticultural layout by the Grootbos Foundation, it is worthwhile to stop and see the wonderful progress of the facility.

For any queries you are welcome to contact the DICT at office@dict.org.za, or phone Alouise Lynch on 0829075607.