South Africa: Demand for Shark Meat Overwhelms Scientists

February 28, 2008

Cape Argus (Cape Town)

26 February 2008Posted to the web 27 February 2008

Cape Town

The increasing international demand for shark meat and shark fins, which is pushing some species towards extinction, has caught marine scientists and managers by surprise, says one of Cape Town's few shark scientists.

"We just weren't ready to deal with the situation," says Alison Kock, a PhD student who is researching False Bay's Great Whites and who works at the Shark Research Centre at the Iziko Museum.

"Regulations either aren't in place or are not effective in conserving most species."

A particular area of concern is Mozambique, where levels of exploitation of many shark species is substantially higher than on the South African coast but where enforcement capacity is limited, says Geremy Cliff of the Natal Sharks Board. Tanzania is also an area of concern.

The two shark scientists were commenting after the announcement last week that nine shark species are being added to the 126 already on the world's endangered list and a warning that oceans are being emptied of sharks by over-fishing and finning.

While the scalloped hammerhead shark, whose population has declined by 99 percent over the past 30 years in some regions, is particularly vulnerable, the smooth hammerhead, shortfin mako, common thresher, big-eye thresher, silky, tiger, bull and dusky sharks will also be added to the list.

Cliff confirmed that eight of the nine species referred to by Julia Baum, a marine ecologist at Scripps Institution of Ocean-ography, had been caught in the province's shark nets.

He said his colleague, Dr Sheldon Dudley both are also members of the Shark Specialist Group was using the Sharks Board's catch records to monitor the population status of the sharks caught in nets.

This data showed population declines of just two of the nine newly listed species: the bull (or Zambezi) and the scalloped hammerhead shark.

"While the shark net catches have impacted on some species more heavily than others, most of the species that are caught in the shark nets are wide-ranging, with the tropical species inhabiting Mozambican and Tanzanian waters, where exploitation levels may be very high."

For example, their data showed that the great hammerhead shark not one of the nine had undergone a significant decline in catch rates in the nets, Cliff said.

"Between 1978 and 1993 we caught an annual average of 13 great hammers. Since 2000 we have only caught two per annum, with none since 2004.

"This species, very much a tropical one, has either changed its dispersal habits and is no longer visiting our waters, or it has been heavily fished to the north of us."

The local nursery ground of the scalloped hammerhead included the Tugela Banks, where the prawn trawlers had caught large numbers of neo-nates (baby sharks), he added.

Kock confirmed that some of the populations of the nine species were being impacted locally, including the shortfin mako through targeted fishing.

"Unfortunately most of the shark fishing that is taking place is not illegal, but rather there are not adequate regulations in place protecting these shark populations effectively at this stage," she said.

"However, South Africa is still in a good position to make a difference in conserving some of these shark populations if we start immediately."

"The perception has been that really wide-ranging species can't become endangered because if they are threatened in one area, surely they'll be fine in another area," said Baum.

"But fisheries now cover all corners of the earth and they're intense enough that these species are being threatened everywhere."