Gangster pack is back, but where are boys?
SCIENCE & TECH / 12 Feb '13, 3:30pmBy: BARBARA COLE
Durban - A gang of girls has moved into the Lower South Coast, baffling locals and causing trouble with fishermen.
They move in packs, are increasing in numbers and no one knows where they come from. No one has a clue if they move on and are replaced by others.
Ocean queen: One of the black-tipped beauties that have moved into the South Coast. Credit: SUPPLIED
And although the girls are reproducing, the fathers are seldom seen.
But here to help sort out the problem is scientist Jessica Escobar-Porras, who is trying to find answers about the “gangster pack” of black tip sharks which have become a tourist attraction at the world-famous Aliwal Shoal Marine Protected Area near Park Rynie.
“That’s the big question: where are the males?” says Escobar-Porras, who is doing a four-year doctorate in the conservation genetics of sharks through the University of KZN’s School of Life Sciences and is already halfway through her research.
“It is exciting but also time-consuming,” said Escobar-Porras, who added that while there were black tips in other parts of the world, nothing was known about those in local waters.
Now her expensive research project is about to receive a shot in the arm from members of the Durban Chapter of the Harley Owners Group (HOGs), based in Umhlanga. The HOGs are backing the Shark Angels – a conservation organisation campaigning for the protection of sharks worldwide – as their charity for the year and the Angels have earmarked the funds for Escobar-Porras’s invaluable research.
“These funds are really going to help a lot,” said Escobar-Porras, who hails from Colombia.
Although there were a few sightings of black tip sharks several years ago, there is now a 50-60 strong population and they are being spotted almost every day, she said.
She wants to know if they are all one big family or small families grouped together, or a cosmopolitan type “city” of sharks coming from all different places like Mauritius and the Seychelles.
They are completely different from the black tips in the Atlantic, however, “and our girls are bigger,” said Escobar-Porras.
“They are mainly females: mothers, grandmothers, sisters, aunts. We have only ever seen two males.
“If they are staying, they have to be protected,” she said.
At the moment, some black tips – so named because of their markings – are being injured by game fishermen trying to prevent the sharks from going after their catches. They are also injured by fishing hooks. Some people catch them.
“The fishermen are not being deliberately malicious or hunting them, but there is a conflict of interest,” said Escobar-Porras.
If the sharks are protected, no one will be allowed to take or injure the sharks.
Escobar-Porras’s research involves taking one centimetre tissue biopsies from the sharks which are then sent off to the university laboratory for DNA and genetic analysis.
Two world champion free divers, Fred Buyle and William Winram, both from Europe, as well as a local expert, Mark Addison, who has a shark diving operation at Park Rynie, collect the tissue using a biopsy gun (a spear gun with a special hollow tip). They then pass the tissue to Escobar-Porras who is on board the boat for later sampling in the university laboratory. The GPS position and the temperature are recorded.
l Plans are already under way to get the Sharks Angels riding with the Harley pack, and the bikers underwater to meet their newfound friends. - Independent on Saturday
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