BRUV Trip on Lwazi

On the afternoon of the 25^th of May 2019, I set off on a new adventure out at sea. I was tasked to help out with the deployment of Baited Remote Underwater Video devices or “BRUVs” around Dyer Island. BRUVs are metal structures that have a Go Pro attached to them for recording activity as well as a bait container to attract species. This is a non-invasive survey technique that is used to assess marine and aquatic ecosystems throughout the world. The survey method offers a unique insight into understanding the abundance, biodiversity and behaviour of shark and ray species in a multitude of habitats without needing to handle or trap individuals.

We loaded Lwazi; our research vessel with our BRUV gear as well as acoustic receivers for a different project. We then set out to sea with our trusty skipper Francois, who located our drop off points for the BRUVs and then guided us through the deployment of each of them at their relevant GPS spots. These locations have to be replicated as precisely as possible in order to maintain data accuracy. We deployed them by dropping them over the side of the boat and then they sink to the bottom of the ocean. The bait canister then starts giving off a scent to attract the species. This aids us in recording the number and variety of species present in a specified area. Three BRUVs were deployed in total and were then left to record for about an hour.

During this hour, we had the opportunity to be part of a separate project and observed how acoustic receivers that had been previously deployed were gathered and then new ones were deployed in the same spot to replace them. This project is aimed at being able to track the number of white sharks that have been tagged with acoustic tags that arrive in the area. After those were recovered and deployed, we went back to our BRUV sites and recovered those.

The boat ride back to Kleinbaai harbour with the sun setting in the distance was a perfect end to the day. Once back to shore, the footage from the BRUVs was downloaded and will be reviewed and analysed for research on small benthic sharks (Dark Shyshark, Leopard Catshark, Puffadder Shyshark and the Pyjama Catshark).

My experience here has been more than I could have ever imagined and I can’t wait for my next adventure out at sea!