Earlier today, Wednesday 15 May 2019, the Department’s SA Agulhas II docked at the at the East Pier Quay in Cape Town after returning from its annual Marion Island 2019 relief voyage.
This Marion Island Relief voyage had a full-list of ship-based scientific activities that included biological, chemical and physical oceanography as well as benthic biodiversity. The ship-based team, led by Chief Scientist Mthuthuzeli Gulekana, comprised of participants from the Department of Environmental Affairs (DEA), South African Environmental Observation Network (SAEON), the South African Weather Services (SAWS) and the University of Cape Town (UCT).
The team juggled their dedicated ship time between research and logistical services, worked 24/7 and managed to complete 90% of the planned activities, these include, but are not limited to using high definition cameras and videos to monitor the benthic biodiversity communities and seabed habitats. Using sophisticated equipment called the CTD to determine the salt and heat content of the seawater as deep as 5000 metres and conducting ocean acidification studies by measuring acidity (pH, total alkalinity) of the seawater around our Marion Island MPA.
Moreover two moored instruments were recovered, serviced and re-deployed to collect year-long trends of current speed and direction, as well as heat and salt content which contributes to long-term monitoring data of the ecosystem around the Prince Edward Islands.
Data was also collected to monitor macro and micro plastics in an attempt to report on marine pollution, as well as collecting weather data using automated weather systems on board the ship and launching meteorological balloons to measure atmospheric conditions.
The preliminary results show that the ocean environment around Marion and Prince Edward Islands is still in a relatively pristine state. This was demonstrated by the seabed pictures showing a healthy ecosystem and no signs of bottom trawling usually caused by fishing.
The observed sea temperatures and water salinity were variable but expected as the environment is influenced by major Southern Ocean climate. Micro and macro plastics were present in the Southern Ocean and this was not unexpected, however the size of the plastic pieces found was surprising for the Southern ocean.
This is because the Southern Ocean is far from any land (mass), major sources of marine pollution are mainly land based and the streams and rivers carry it into the ocean. Therefore plastics which were expected to be found would be smaller and in less quantity, because smaller size plastics would indicate that they have been in the water the longest and have been broken down.
The plastics quantity and size relatively increased on the approach towards the South African coast. On the base there were also numerous island-based scientific research programmes, which include, marine mammals, botany, geomorphology and space weather, under the island-based Chief Scientist, Professor Nico de Bruyn from the University of Pretoria.
Source: Department of Environmental Affairs