The South African maritime research vessel SA Agulhas II is back in Cape Town after her annual Marion island relief voyage which also saw tasks performed as part of South Africa’s international responsibility in the Southern Ocean.
“This Marion Island relief voyage had a full list of ship-based scientific activities including biological, chemical and physical oceanography as well as benthic biodiversity. The ship-based team, led by chief scientist Mthuthuzeli Gulekana, included 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),” according to a DEA statement.
“The team juggled time between research and logistic services, worked 24/7 and managed to complete 90% of planned activities. These included, but were not limited to using high definition cameras and videos to monitor benthic biodiversity communities and seabed habitats. Using sophisticated equipment called the CTD saw salt and heat content of seawater as deep as 5000 metres determined and ocean acidification studies by measuring acidity (pH, total alkalinity) of seawater around the Marion Island MPA (maritime protected areas) was also conducted.
“A pair of moored instruments was recovered, serviced and re-deployed to collect year-long trends of current speed and direction, as well as heat and salt content contributing to long-term monitoring data of the ecosystem around the Prince Edward Islands.
“Data was also collected to monitor macro and micro plastics to report on marine pollution, as well as collecting weather data using automated weather systems aboard and launching meteorological balloons to measure atmospheric conditions.
“Preliminary results show the ocean environment around Marion and Prince Edward islands is in a relatively pristine state. This was demonstrated by seabed pictures showing a healthy ecosystem and no signs of bottom trawling usually caused by fishing,” the statement said.
The statement notes macro and micro plastics were present in the Southern Ocean – “not unexpected, but the size of pieces found was surprising”.
This because the Southern Ocean is far from any land mass and major pollution sources are mainly land-based with streams and rivers carrying it into the ocean.
“The plastics quantity and size increased on the approach to the South African coast,” the statement said further.