In the video above, people are shocked that a fisherman accidentally caught two great whites off of the pier at Manhattan Beach in Los Angeles in the same day (both sharks were released). But, in fact, this isn’t too surprising given that the waters off of Southern California are the main nursery grounds for our west coast population of great white sharks.
Researchers believe young great white shark “pups” spend their first couple years in the warm ocean waters off Southern California and Northern Mexico, where they feed on several species of forage fish like squid, mackerel, anchovies, sardines and hake. Researchers also believe Southern California waters may serve as birthing sites for great white pups as well. After reaching about 6 years of age, great whites get big enough to join the other adult sharks that feed on seals and sea lions, playing an important ecological role as some of the ocean’s few natural predators. Ultimately, this helps keep our ocean food web in balance, ensuring healthy marine wildlife populations and vibrant fishing opportunities.
Unfortunately, some of our less selective fishing methods known as set and drift gillnets overlap with great white shark nursery grounds, and continue to catch these great white shark pups as they swim into the entangling mesh. In fact, over 80% of the reported bycatch of white shark pups occurs in these gillnets, which are intended to catch halibut, swordfish, white seabass, and other fish. No one knows the full extent of this white shark bycatch, but it does appear that white shark interactions are more common in certain discrete areas that may be congregation sites where the shark pups are feeding. While it is illegal to intentionally catch and sell white sharks, there are currently no limits on the bycatch, nor are there sufficient fishery observers to accurately document the number of interactions.
Our West Coast great white sharks are a genetically distinct and isolated population from all other great whites around the world, and they are facing a perilous situation. Recent population estimates of only a few hundred West Coast adults put these sharks at risk of extinction. Great white sharks take about a decade to reach maturity, grow slowly, and bear few young over their lifetime. While many factors may be at play, bycatch is the biggest source of mortality that we can do something about.
For as much as we have learned about great white sharks in the last three decades, there is still so much about the secret lives of young great white shark pups that remains a mystery. But, as we have seen with other endangered species, listing this population could increase funding research on these iconic, powerful ocean predators. An “endangered” status will also set the stage for new safeguards to prevent incidental catch of great white sharks in commercial entangling nets that threaten the very future existence of this top predator that has been swimming in our oceans for millions of years.
Thanks to over 44,000 Oceana supporters who signed our petition to the National Marine Fisheries Service, this population is currently under full review for protection under the Endangered Species Act. Thanks for your support in helping us protect this incredibly powerful, but vulnerable, ocean predator!
- Disabled Killer Whale Survives with Help from Its Pod Posted Tue, May 21, 2013
- Oceana CEO Andy Sharpless Discusses His New Book, The Perfect Protein Posted Wed, May 22, 2013
- Happy World Turtle Day! Posted Thu, May 23, 2013
- Washington Passes Legislation to Fight Seafood Fraud Posted Fri, May 24, 2013