Nelson Mandela University (NMU) plunged into the big blue on Wednesday with presentations on deep sea canyons, climate change and measures taken to protect SA’s only resident whale species.
It was the first day of the “science to impact” symposium, celebrating the work of NMU’s Institute for Coastal and Marine Research and pioneering ocean scientist Prof Mandy Lombard.
Most of the 35-odd speakers scheduled to speak over the next three days studied at some point under Lombard or have partnered with her.
She has headed up the NMU-based SA Research Chair on marine spatial planning for the past decade, a key factor in the leading role played by the university in ocean science, nationally and internationally.
Njabelo Mdluli, 27, who did his masters under Lombard, explained his work on the deep sea canyons off iSimangaliso Wetland Park in northern KwaZulu-Natal.
“Our understanding was these canyons might be interrupting the flow of the Agulhas Current.
“But was this happening and if so what was that doing to the production of plankton, as the vital base of the marine food chain?”
He said after extensive sampling in the waters above the six different canyons, he realised the middle one was throwing up particularly positive results.
“I was seeing lots of phytoplankton, which pointed to a large volume of nutrients, which clearly must have been brought up off the ocean floor.
“The water temperature in that area was also colder, supporting the fact that this upwelling dynamic was happening.”
Mdluli said it seemed that the “geomorphology” of each canyon — including its shape and size and the nature of the sea floor — underpinned its capacity to support plankton.
“So we need more work done on the geomorphology of these underwater canyons, including the ones here off Algoa Bay.”
He said while his research might seem obscure to some, it spoke to the heart of things.
“It’s all about tracking and understanding the basis of life on earth.”
Earlier, in her keynote presentation, Prof Elizabeth Wentz, from Arizona State University, described how helping communities to visualise multiple causes and effects empowered them to act.
An initial project in Rhode Island focused on the problem of sewage spills into the local river system and thereby the ocean.
“This was happening when it rained but how much rain needed to fall to trigger a situation where fishing and swimming were hazardous?
“We realised it depended on several factors including the geography at different points of the coast and how quickly the sewage was dissipating there.
“We punched in all our findings and produced a model which helped to inform and protect that community.”
Wentz said in Costa Rica she found that pesticides were running into the environment from banana plantations and affecting human drinking water.
“It was found that this was in turn negatively affecting male fertility.
“But through our data integration and visualisation work the affected communities were able to act to improve policy on the use of pesticides.”
She said in Arizona, climate change was pushing up the already high temperatures, resulting in a number of deaths each year.
“The people who can afford to, run their air conditioning 24/7 through the summer, while those struggling financially are at risk.”
By highlighting this link, she and her team had managed to convince the authorities to give further assistance to people in mobile homes.
This was a step in the right direction though the increased use of electricity meant increased pressure on water supplies needed to cool power generators and this issue would also have to be tackled.
“Each project is a small wind blowing towards ... a more resilient planet,” Wentz said.
Plettenburg Bay-based marine mammal expert Dr Gwenith Penry described her work to protect Bryde’s whales by getting the seabed octopus trap fishery to change its technique.
She said the whales chased their prey, ranging from fish to crabs and lobsters, at high speed along the sea floor.
“This explained how the rope connecting the octopus traps became lodged in the whales’ mouths, anchoring them to the seafloor.
“Because Bryde’s are resident in South African coastal waters, seasonal closures would not help.
“The only viable option whereby the fishery could continue without entanglements was to remove all rope from the water column by using sinking groundlines and acoustic or time-release surface-marker buoy lines.”
Penry said while this policy change had been implemented the octopus trap fishermen had mostly not yet returned so its effectiveness still needed to be tested.
The Herald
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