Ocean’s supersized star spotted

Oprah, a great white shark, was one of 36 tagged in Western Cape from March to May 2012. Picture: www.ocearch.org

Oprah, a great white shark, was one of 36 tagged in Western Cape from March to May 2012. Picture: www.ocearch.org

Published Jun 6, 2014


Durban - Oprah has been spotted off the coast of Durban, which is causing a buzz – not among fans of the former talk-show host, but rather scientists tracking her namesake, a great white shark.

The immature female, one of 36 great white sharks tagged in the Western Cape from March to May 2012, is the latest to transmit a satellite signal with her location.

Since Monday, she was near Durban, possibly attracted by the looming annual sardine run, said Dr Alison Kock, research manager at Shark Spotters in Cape Town.

“Great whites are very opportunistic; they go where food sources are predictable and available in abundance.”

Kock was in Durban on Tuesday along with international scientists, who gathered to share their research of the predators at the second annual Sharks International Symposium hosted this year by the KwaZulu-Natal Sharks Board.

Information sharing is one of the reasons the Ocearch project broke new ground in South Africa. It made data readily available to researchers and the public on its website.

Kock, was one of about 40 scientists researching sharks in the country and who went on Ocearch’s great white shark-tagging expedition. The non-profit organisation began research on top marine predators two years ago.

“It’s the first of its kind. All the different research groups were doing their own thing and once a shark moved to a different area, we lost track of it. This project allowed us to come together as scientists,” she said.

Although this is just one of the projects her organisation is involved in, Kock cannot keep herself from checking the Ocearch Global Shark Tracker, at least once a day.

Scientists are hoping the data it provides can help answer questions about the movement, biology and health of great white sharks off the coast of Southern Africa, especially when they venture into Mozambican waters where they are not protected.

At the time of tagging, Oprah weighed more than 300kg and was 3m long. Kock said she would be much bigger and heavier now. Great whites are estimated to grow about 20cm to 30cm a year.

Kock said it is a myth that great white sharks fed only on seals.

“They are big, so they eat a lot and whatever is easy to catch.” For the younger great whites, that could include sardines.

Oprah was fitted with a Smart Position or Temperature Transmitting Tag (SPOT) in Mossel Bay in March 2012.

The tag, which was attached to her dorsal fin, transmits a signal to a satellite when the fin breaks the surface of the water. The satellite then sends back an estimated location – this is called pinging.

Before Monday’s ping at 3.54pm, she had last been located in Gansbaai last month.

This was exciting news in the world of shark research as merely fitting a tag does not guarantee any data feedback.

At the symposium, Dylan Irion, a scientist with Oceans Research, highlighted what could go wrong with the tags.

He said of the 36 sharks tagged, at least two had died. Tags on three sharks had fallen off and an aerial had broken from another.

A further hindrance to the functioning of a tag was the build up of micro-organisms, plants, algae or animals clinging to the device. This was known as biofouling.

Like other researchers, Irion hopes Oprah will not run into trouble as she completes her migration pattern – she is expected to return to her mating ground as female great whites do every two years.

The shark was named by Ocearch founding chairman and expedition leader, Chris Fischer. He hosts Shark Men, a show on the National Geographic Channel.

Fischer named her Oprah after the former talk show host because of her contribution to education in Africa.

The conference continues until tomorrow. - The Mercury

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