Walvis Bay — An isolated community of bottle-nose dolphins; killer whales killing leatherback turtles (never heard of before); and uncommon lethal box jellyfish are just the tip of the iceberg of what the sea off Namibia’s central coast has to offer.
“There is still much to learn. But even with Namibia’s excellent fisheries management, not much is really known of what else lives in the waters out here, or how they behave,” said Dr Simon Elwen of the Namibian Dolphin Project and member of the Pretoria University’s Mammal Research Institute.
He was speaking at the recent handover of a donation of N$206 000 from Nedbank’s ‘Go Green’ Initiative towards the project.
The Namibian Dolphin Project was established in 2008 and it is a research and conservation project working in Walvis Bay and Lüderitz. The goals of the project are to gather data on the abundance, distribution and habitat use of whales and dolphins in Namibia.
Dr Elwen was giving a short presentation of what has been recorded until now, which he described as unique compared to the behaviour of similar species elsewhere.
The local population of common bottle-nose dolphins, which are prevalent around the globe, are special in the sense that this fairly small community of about 80 members is “very isolated”, according to Dr Elwen. The dolphins live and move mainly between Walvis Bay and Swakopmund, and may sometimes be found off Lüderitz or just north of Swakopmund.
“Their nearest neighbours are somewhere along the coast in south Angola,” he said.
There are concerns that development along the central coast, and eco-tourism, may be affecting the behaviour of these ocean creatures, as their numbers have apparently decreased by about seven percent since 2008.
“We are concerned about this, and although human threats are real and increasing, it is not obvious how or whether this is in fact impacting on these dolphins’ behaviour. There is a concern though that there are possible permanent movements away from the area by some individuals,” he said.
According to him, the project is working very closely with local tour operators in capturing more data, but also educating the operators in how to lessen the impact the industry has on the animals.
The other concern is the development of Namport’s container terminal expansion, and desalination projects that will cause pollution, noise and possible chemical effluent, which will also affect the dolphins’ normal behaviour.
The behaviour of local whales, especially killer whales or orcas, is also unique in that there have been more reports of orcas hunting and killing leatherback turtles.
“This has never been recorded before, so it will be interesting to get more information on why this happens here,” Dr Elwen said.
Over the last few years several leatherback turtles have washed ashore and their deaths could not be explained, prompting the authorities to call for an investigation into the mortalities.
Dr Elwen also noted an increase of box jellyfish, which he described as “potentially lethal”, off Lüderitz. He added that two of these jellyfish had been spotted near Walvis Bay recently.
According to him, much data still needs to be collected regarding the movement and behaviour of whales and dolphins especially. The project will therefore expand its operations to offshore marine protected areas near Lüderitz over the next two years, which will be assisted by Nedbank’s ‘Go Green’ fund.