Coast KZN

16 Feb 2018

‘Sound’ help for dolphin research

Dave Savides (Zululand Observer) Picture: Yusuf Suliman of DHL Express with the hydrophone containing a memory card filled with recorded dolphin soundings vital for research purposes (Photo: Dave Savides)

Humpback dolphin soundings ready for researchers

Valuable audio information on Richards Bay’s endangered Humpback dolphins will be analysed by marine biologists this week thanks to a valuable gesture by the business sector.

In addition to a live camera feed that monitors the creatures’ activities in relation to shark nets at Alkantstrand and Newark beaches, the dolphin research team last year installed a hydrophone (underwater microphone) near the harbour mouth.

The KZN Sharks Board offered the researchers the use of the hydrophone to investigate the behaviour of the dolphins near the shark net that catches more Humpback dolphins than any other in KZN.

This should form a strategy to prevent the deaths.

The hydrophone records dolphin sounds, mostly clicks and whistles – since unlike humans, they do not have vocal chords in their throats.

The clicks are produced through the nasal sac on the top of the head and the whistles are generated through the blowhole.

The sounds are used as ‘sonar’ while navigating and hunting prey, as well as for communication and identification.

An added bonus at Richards Bay has been the capturing on the hydrophone of beautiful whale ‘songs’ during the migration season.

But the memory card on the instrument became full and after it was retrieved by the KZN Sharks Board on Tuesday morning, help was sought to get it to Johannesburg for downloading and analysis.

On request, Yusuf Suliman of DHL Express responded unhesitatingly, offering to package and transport the hydrophone at no cost as his company’s contribution to this important scientific research.

‘We are always extremely grateful for the response we get from dolphin lovers, in this case DHL,’ said marine biologist Shanan Atkins of the School of Animal, Plant and Environmental Science at the University of Witwatersrand, who heads the research project.

‘The contribution of citizen scientists and supporters enables us to function optimally.’
A recent SA-wide study indicated the number of Humpback dolphins at roughly 500, which is half that previously estimated.

They are deemed to be the country’s most endangered resident marine mammal, facing a high risk of extinction – making research and preservation a top priority.