Cape Town - A team of researchers from the Department of Environmental Affairs (DEA) returned on Thursday from a four-week expedition aboard the Research Vessel Algoa.
The expedition took place with the overarching aim of documenting, and exploring, some of the uncharted areas of the largest known submarine canyon off the South African west coast - the Cape Canyon.
Covering an area of over 30 000 square kilometres, the expedition collected information on the geology, oceanography and biodiversity. One of the most notable successes of the expedition is the capture of visual evidence of the rocky habitat of the Cape Canyon seafloor.
The Cape Canyon is but one of a substantial amount of underwater canyons off South Africa’s coasts. These underwater features are reported to potentially play a significant ecological role and the unique structure of these canyons also connects the coastline to the deep-sea environment.
Pumpkin urchins, brisignids, yellow hydroids, white lace coral and solitary corals (Photo: Department of Environmental Affairs)
The DEA Oceans and Coast Branch, in light of the canyon’s varied potential ecological services, initiated a 3-year collaborative project in order to provide insights on the functionality of the Cape Canyon in relation to nearshore and offshore areas.
The survey made use of a variety of ship-based sampling methods, including a tow-camera system that captures image and video of the seabed, a dredge which collects invertebrate animal samples from above the seabed, a bottom sampler used to collect sediment from the seafloor and a Conductivity Temperature Depth (CTD) device that collects information on temperature, salinity, conductivity and collects water samples at different depths to analyse environmental variables.
In addition to these sample collecting methods and equipment, an acoustic device was employed to produce a map outlining the topography of the canyon.
The data collected on this trip will go toward informing and complimenting, South Africa’s Marine Spatial Planning efforts.
White soft corals and lace corals (Photo: Department of Environmental Affairs)
Eel with white soft coral in the foreground, encrusing sponges on the rocks (Photo: Department of Environmental Affairs)