The coastal waters off San Diego County are home to a variety of sharks, from the leopard sharks hanging out in La Jolla Cove to the large mako sharks in deep water beyond the continental shelf.
Experience these local predators up close during Shark Week at the Birch Aquarium at Scripps from July 18 to 24. The annual event features shark exhibits, talks and dive shows, as well as hands-on encounters with shark pups and scavenger hunts.
By learning about these fascinating creatures, visitors of all ages will hopefully lose any misconceptions or unnecessary fears they have of them, and come to understand and appreciate their importance, said Michelle Hofmann, the aquarium's interpretive programs coordinator.
"We want to connect people to sharks in a positive way so they will want to support them," Hofmann said.
While their toothy mouths and pointy fins instill fear into many humans, the scariest thing about sharks is their chances for survival.
Threat of their own
Many of the almost 400 species of sharks worldwide are facing increasing threats from overfishing, by-catch and finning.
Many sharks are caught and killed in commercial fishing nets set for other fish, like tuna, which is called by-catch.
However, some sharks are being more intensely targeted for their fins, which are a profitable delicacy used in dishes such as shark fin soup. Finning often means a sharks' fins are cut off and the body is thrown back into the ocean. An estimated 100 million sharks are harvested each year, Hofmann said.
"The fishing industry is catching sharks at a faster rate than can be sustained by reproduction," said Jeffrey Graham, a marine biologist with Scripps Institute of Oceanography. "We're going to go through a period of time when a lot of sharks drop down to very low numbers."
Slow to reproduce
Having been so successful at the top of the marine food chain, sharks have not evolved to reproduce quickly or in great numbers - there's been no need. Some sharks take between as many as 15 years to reach sexual maturity, and produce 100 pups every one to two years (as compared to millions of eggs laid by tuna).
Some sharks lay eggs, while others, like the blue shark (another open ocean species in the area), carry pups to term. If pregnant females are caught before they give birth, it has a long-lasting impact.
"You may be removing the next five years of sharks, taking out lots of mothers," Graham said, who has studied sharks for almost 30 years.
Affected food chain
Taking out the apex predator of an ecosystem can have widespread consequences. For example, when a reef shark was wiped out by fisherman, its prey, grouper fish, exploded. That, in turn, decimated a smaller fish that cleaned the reef. Without this smaller fish, the reef died, taking the entire ecosystem it supported with it.
"If you love to snorkel you should love sharks; if you love coral reefs you should love sharks," Hofmann said.
Upsetting the balance of an ecosystem can also impact fisheries, Graham said. For example, taking out sharks that keep the stingray population in check can significantly disrupt scallop fishery operations.