Are Great White Sharks Endangered?

Trophy hunting for great whites may make them endangered

Trophy hunting is one of several reasons why white sharks may be listed as endangered.

No – great white sharks are not listed as Endangered, but they are currently listed as a Vulnerable species on the IUCN Red List of Threatened Species. Reasons for this include their relative scarcity compared to other sharks, their slow reproduction speed, and the high demand for shark related products.

However, with new population studies publishing results, it wouldn’t be surprising if white sharks are listed as endangered in the near future.

In 2012, Oceana, Shark Stewards, and the Center for Biological Diversity all filed petitions to list white sharks as endangered. This prompted the National Marine Fisheries Service and the California Department of Fish and Wildlife to conduct a census of the white sharks on the California coast.

Identifying individual sharks by their dorsal fins, they estimated that only 219 white sharks (both adult and juvenile) were living off Central California, with about double that amount living along the Pacific coastline in the United States.

Of course, these numbers are controversial – the study assumed that the California population of white sharks was closed (i.e. no sharks left or joined the population during the time period of the study). Another census suggests that the actual population may be more around 2000.

The more important question, says research scientist Sal Jorgensen of the Monterey Bay Aquarium, should be “is the number of white sharks rising or falling?”

Another study, based out of the white shark hot spot of Gansbaai, South Africa, published its results a few days ago. Using 1683 images of dorsal fins collected over 4000 hours of research by the Dyer Island Conservation Trust, the study identified 532 unique individuals.

The study then used statistical methods to estimate the overall numbers of the white shark “super-population” living off the African coastline, thought to migrate as far as Australia. Their results: even the “super” population contained only 908 individuals, which was half of what researchers were expecting.

In their conclusion, the researchers suggested that even though white sharks have been protected in South Africa since 1991, the population hasn’t recovered enough to sustain growth. This will certainly generate followup studies and rebuttals, so it will be interesting to see how many studies end up with this same conclusion.

Either way, tagging white sharks off Cape Cod, supported by the Atlantic White Shark Conservancy, helps researchers understand the local population, which in turn helps paint a clearer picture of the white shark population overall.

Sources:

Phys.org – Are Great White Sharks Endangered? 

IUCN Red List – Carcharodon carcharias 

IOL Scitech – It’s a Great White Shock

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