In between documentaries, live footage, and suspicious research on sharks eating fishing boats, viewers of Discovery Channel’s “Shark Week” may have seen a surprising PSA by Oceana featuring Mad Men’s January Jones. Amidst footage of great whites, she declares, “Healthy oceans need sharks. But great whites are in danger of extinction. Too many are being caught in fishing nets. There may be only a few hundred adult great whites left off the West Coast. We should be scared FOR great whites.”
She is right on many counts. Healthy oceans do need sharks — as an apex predator, whites are extremely vulnerable to extinction. The top of the food chain is a dangerous place to be, as the ocean can only support a small population at any given time. Little is known about mating, reproduction, or population numbers of great white sharks, due to their speed and evasiveness. They have been recorded at up to 4,000 feet below sea level, making it impossible to observe and study them in their natural habitat. However, enough is known about them to classify the species as a whole as vulnerable to extinction, due to fishing, pollution, and habitat destruction. On top of their already precarious position, great whites are often misunderstood as violent, ferocious creatures, making it difficult for conservation efforts to find funding and public support.
However, this particular PSA was not on great whites as a whole, but rather focused on a very specific group. Off the coast of California and Mexico, there is a population of great white sharks genetically distinct from others around the world. They favor the coast of central California, and the waters just off of Guadalupe Island in Mexico. In March of 2011, this population was estimated by a team of researchers at only 219 adult sharks. As the lead scientist on the project, Taylor Chapple, stated, the population is “lower than expected, and also substantially smaller than populations of other large marine predators, such as killer whales and polar bears.” Although this estimate comes with little context, such as the overall population trend of great whites or the amount of juvenile sharks in the group, the number seems dire. Any losses in a clade that small could be devastating, particularly the loss of younger sharks. Great whites take an average of 15 years to reach sexual maturity. Those lost before then will never reproduce and replenish the population.
Although the number seems low, the estimate is still controversial among many scientists, given that there is no other population to compare it to. Two hundred nineteen may be a perfectly healthy population for adult sharks, and such a low number is not unheard of in other apex predators. In fact, the National Oceanic and Atmospheric Administration (NOAA) decided this past June that great whites would not be listed under the U.S. Endangered Species Act, despite two petitions for its listing. Many consider the great white to be a major conservation success story, due to their protection under the Marine Mammal Protection act of 1972, Proposition 132 banning coastal nets, and a statewide ban in California on the fishing and sale of all white sharks. The population has appeared as relatively unchanged since the 1990s, leading the NOAA to declare that great whites off the California coast have a “low to very low risk of extinction now and in the foreseeable future.”
The PSA that aired during Shark Week was accurate in its statements: Healthy oceans do need sharks, fishing nets pose a great danger to juvenile sharks, and there are only a few hundred adult sharks left off the California coast. However, this particular species' danger of going extinct pales in comparison to that of other fish around the world. The great white is not even listed among the 20 most threatened shark species, and is not included on the IUCN Red List of species close to extinction. Although the great white is a necessary and vulnerable species, there are others that deserve the same attention.