New shark cable set for False Bay

A line marks the spot where the new electronic shark repellent cable was placed off Glencairn beach. Picture: INSTITUTE FOR MARITIME TECHNOLOGY

A line marks the spot where the new electronic shark repellent cable was placed off Glencairn beach. Picture: INSTITUTE FOR MARITIME TECHNOLOGY

Published Sep 26, 2014

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Cape Town - Cape Town beaches may have electronic devices set up in the sea to keep great white sharks offshore – if the new gadgets prove effective.

Staff of the KwaZulu-Natal Sharks Board gave a briefing on Thursday on their new electronic shark repellent cable, which is to be installed off Glencairn beach in False Bay on Wednesday.

The 100m cable, designed to emit a low-frequency, low-power electronic field, will be fixed to the seabed with vertical “risers”.

The idea is that sharks, which are extremely sensitive to electric fields, will move away from the area once they detect the electronic field.

In line with the conditions of a permit from the Department of Environmental Affairs, the cable is to be activated on November 1, by which time most migratory southern right whales would have left False Bay for the Antarctic.

It is to be removed at the end of March.

Geremy Cliff, head of research at the sharks board, emphasised the cable was being tested. It would be deployed so as not to exclude sharks from approaching Glencairn beach.

“It is important for the public to understand this is a scientific experiment. The cable won’t create a safe haven for them in Glencairn.”

The cable was invented by the sharks board and uses the same technology as its “shark pod”, used by surfers.

The board had been looking at alternatives to the shark nets and drums used on the KZN South Coast.

Cliff said it was decided to test the device at Glencairn because white sharks spent a lot of time in False Bay, there was a good understanding of their movements along the coast from Muizenberg to Glencairn, the water was fairly shallow and calm, and there were good vantage spots on the nearby Elsies Peak to observe sharks’ behaviour when they encountered the cable.

A video camera will be installed on the peak to record sharks’ reactions.

“We have an exposed coastline in KwaZulu-Natal, not the luxury of False Bay, and although we do get white sharks up there, they’re not nearly as common. If we get a reasonable number of interactions with sharks, the experiment could be completed this summer.”

The cable has been tested for human safety at the highest intensities, without problems. The Institute for Maritime Technology, a division of Armscor and in Simon’s Town, was contracted to design and build the cable.

The sharks board said nothing would be done to attract sharks to the area and the beach would stay open. The experiment has the backing of the city council.

Gregg Oelofse, head of environmental policy and strategy, described the experiment as “really exciting”.

“If it proves effective it could potentially replace shark nets in KwaZulu-Natal and it could potentially be used off beaches in Cape Town.”

Cape Times

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