When sharks are prey

When sharks are prey

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Fri, 12/04/2013 - 13:03

News about the slaughtering of three whale sharks in Suez in the past weeks triggered a wave of anger among marine biologists and environmental organizations across Egypt.

The Hurghada Environmental Protection and Conservation Association (HEPCA) condemned the recurring slaughter of this peaceful and endangered species, describing it as a “serious environmental crime.”

“Some media outlets have reported the news of the slaughter of whale sharks in Suez as a heroic act, even though it is a real disaster,” says Mahmoud Hassan Hanafy, a marine environment professor at Suez Canal University and HEPCA’s scientific adviser.

Hanafy adds that the International Union for Conservation of Nature and Natural Resources, a Switzerland-based environmental organization, lists whale sharks as a “vulnerable” species, and Egypt has signed international agreements that bind it to protect such endangered species.

Regular appearances of whale sharks in the Suez area are an important trend that needs to be scientifically examined, he explains, saying Egypt so far has not gathered much data on this species.

“There are no accurate records or database on whale sharks in Egypt, although the existence of this rare species could be economically exploited, as it provides a guarantee for a healthy marine environment, which attracts divers,” Hanafy adds.

After HEPCA filed a complaint, Tourism Minister Hesham Zaazou ordered an investigation into the hunting of sharks in the Red Sea, but no results have yet been released.

Mohamed Abul Regal, professor of marine ecology and ichthyoplankton (the eggs and larvae of fish) at the Port Said University Faculty of Science, says the whale shark is a slow-moving, filter-feeding shark and the largest living species of fish. Whale sharks can reach 20 meters in length and live up to 60 years — if they are not hunted by Suez fishermen, that is.

Unlike other types of sharks, whale sharks feed on a wide variety of planktonic (microscopic) and nektonic (larger, free-swimming) prey, such as small crustaceans, schools of fish, and occasionally tuna and squid. Phytoplankton, or microscopic plants, and macroalgae can also form part of their diet.

“Ecologically, whale sharks indicate an ecosystem rich in fish that feeds on plankton that will in turn attract more valuable species, such as tuna,” Abul Regal says.

Whale sharks are harmless and have rarely posed a danger to humans. However, there have been a few cases of whale sharks butting their heads against sport fishing boats, possibly after being provoked.

“Usually, these sharks are more at risk from being struck accidentally by vessels while basking or feeding on the surface,” he says.

In some countries, hundreds of whale sharks are hunted down on a yearly basis as food products. Oil from the whale shark’s liver is extracted to create a waterproof liquid for fishing boats, in shoe polishing products and to treat skin diseases.

Hanafy says eating shark meat is not healthy because, as the top predator, sharks accumulate dangerous levels of mercury and other toxic heavy metals. This can eventually cause many health problems, especially for children.

“As a civil society association, our role is to launch monitoring and data collecting programs about these endangered species, to eventually help support decision makers,” Hanafy adds.

In addition to the existing monitoring programs on sea turtles, sharks, coral reefs and dolphins, HEPCA, he says, has a whale shark study program in the pipeline.