Progress made from across the ocean; the SAEON Stereo-BRUV project in South Africa
Sarah Halse
The first stereo-BRUV attempt in South Africa was very successful, which bodes well for its future in South African monitoring. We managed to collect 144 samples from a variety of depths and profiles both inside and outside the Tsitsikamma Marine Protected Area (MPA).
The Tsitsikamma MPA is situated in the centre of the warm-temperate Agulhas Ecoregion which stretches along the southern coastline of South Africa. The Tsitsikamma MPA is the oldest (proclaimed in 1964), and one of the largest (323 km2), no-take MPAs in Africa. The subtidal communities provide one of the best examples of pre-exploitation inshore ecosystems available in southern Africa, allowing for a more thorough assessment of the remote camera methods ability to survey subtidal rocky reef fish communities in the Agulhas Ecoregion.
This first field trip was somewhat of a learning experience, and we hope the next fieldtrip is July will be smoother and quicker. We figured our way around utilising a smaller boat than usually employed in stereo-BRUV research, to make for the most efficient use of time and funds. Smaller things like catching ropes in propellers, clearing footage that has just been collected and getting a system stuck on a high profile reef at 80 metres are some of the hurdles, which hopefully will not be repeated. These however add to the learning experience that is stereo-BRUV fieldwork.
We’ve seen some beautiful and some not-so-beautiful footage so far, from large schools of striped bonitos (Sarda orientalis), frames with over twenty-four roman (Chrysoblephus laticeps), an important line-fisheries species, pyjama catsharks accidently attacking fellow pyjama catsharks (Poroderma africanum), a beaten up and very large old raggie (Carcharias taurus) and an over inquisitive cowshark (Notorynchus cepedianus). My advice to any aspiring stereo-BRUVers is data storage, and lots of it. The videos tend to be quite large and when you’re working with two per sample the more space you have the better. We’ve also found water quality in this particular Ecoregion to cause a few challenges, however this can all be overcome with bigger sample sizes. Overall the use of stereo-BRUV has been a huge success - already initial analysis has detected larger biodiversity and fish abundances than during angling surveys.
Conference abstracts submitted:
PARKER, D., Götz, A., Winker, H. and A.T.F. Bernard. Optimizing long-term monitoring for assessing subtidal reef fish communities: introduction of the novel stereo-BRUV sampling technique. Western Indian Ocean Marine Science Association Symposium, Maputo, Mozambique, 28th October - 2nd November 2011.
Bernard, A.T.F., Götz, A. and H. Winker. Cost-efficient monitoring of reef fish in the Agulhas Ecoregion of South Africa. Western Indian Ocean Marine Science Association Symposium, Maputo, Mozambique, 28th October - 2nd November 2011.
Popular articles published:
HALSE, S.J. (2013) Pioneering stereo-BRUV for long-term monitoring in Africa. SAEON eNews.
This may be viewed for the full story and some pics at:
http://www.saeon.ac.za/enewsletter/archives/2013/april2013/doc03
