Sharks may well be the most fascinating and misunderstood animals in the ocean. Their ancestors swam the seas when dinosaurs roamed the shores, and sharks have survived eons of change on Earth. Today, their future is uncertain.
Despite their powerful presence in the human imagination, sharks remain creatures of mystery. We know little about their lives, including where and how they live, and where their young are born. They're identified internationally as vulnerable to extinction, and protected in many parts of the world.
Since 2002, we and our research colleagues at Stanford University, California State University, Long Beach, and other institutions have worked to expand our understanding of white sharks. We're making significant contributions to knowledge about where white sharks in the eastern Pacific Ocean travel, where they live and about their basic physiology. The new data are generated from electronic tracking tags, photo identification and genetic analyses using tissue and blood samples collected from adult and juvenile sharks.
We're combining field tagging with laboratory studies—and working to advance policies that will identify and protect critical habitat for sharks and other species. We also promote policies in the U.S. and internationally to end practices that threaten all shark species: the targeting of sharks for their lucrative fins, and the use of indiscriminate fishing practices that catch and kill sharks in gear intended for other species.
Despite popular perceptions of sharks as invincible, shark populations around the world are declining because of overfishing, habitat destruction and other human activities. Of the 501 or so species of sharks, 79 are imperiled, according to the International Union for the Conservation of Nature. White sharks are top predators in the sea but they're in grave danger of being depleted.
While over 100 nations fish for sharks, only a handful have enacted regulations to protect them. Most white shark research and conservation groups are located in places where the population of white sharks is highest—off California, South Africa and Australia. These regions, as well as U.S. waters off the East Coast and Gulf of Mexico, have laws that protect white sharks from either harassment or killing and the sale of body parts.
In October 2004, white sharks gained protection in a global wildlife treaty approved by the U.N.-affiliated Convention on International Trade in Endangered Species (CITES). The 166 member countries in CITES approved regulations requiring a controlled system of permits for all international trade in white shark parts and products. Under the new regulations, trade is closely monitored, and may be banned altogether if white shark numbers keep fading.
Shark finning, the practice of cutting fins from a living shark and then tossing its body back into the ocean, is another threat. Millions of sharks worldwide are killed for fins each year. Fortunately, states and countries worldwide are banning this practice. In 2011, an Aquarium-sponsored bill passed with tremendous public support, banning the trade of shark fins in California.
Small in numbers, slow to reproduce and distributed throughout the world, white sharks are vulnerable to exploitation. Their relatively small numbers have been further reduced by fishing to feed the curio trade, by incidental catch in commercial fishing gear that targets other species and by sportfishing. Scientists hope that tagging and other research methods can unlock the mystery of the white shark and assist in global conservation efforts.
The Aquarium is promoting innovative study, awareness and conservation of white sharks. Through our work we can promote public understanding and protection of this ecologically important and threatened species.
Our research involves:
- Juvenile White Shark Research: Juvenile "young of the year" white sharks are found each summer in the Southern California Bight and as bycatch in the fisheries of Mexico and California. Yet we don't know where they're born, who the parents are, where breeding occurs or how they join adult populations. We're studying their movement, habitats, diet, population size and how they're affected by environmental toxins.
- Adult White Shark Research: We're learning how to protect adult white sharks from overfishing and the effects of bycatch by studying their movement, population size and foraging patterns.
- White Shark Genetics: To conserve white sharks, we need to know more about the movement between our coastal white sharks and those of Mexico, Australia, New Zealand and South Africa. Genetic (DNA) studies provide clues about population structure, parentage and the origins of white shark products found in global fish markets.
The Art and Science of Tagging Juveniles
Juvenile sharks are fitted with an externally attached, pop-up satellite tag with a tiny computer that collects and stores data on temperature, depth and light (used to estimate position). On a preprogrammed date, the tag pops off and floats to the surface. At the surface it transmits data to us via satellite. If the tag is recovered, even more data is retrieved. To date, scientists have tagged and tracked 18 juveniles and 167 adults.
Juvenile white shark tagging is coordinated by the Aquarium but partners include the Tuna Research and Conservation Center (TRCC), a collaboration between the Aquarium and Stanford University; the University of Hawaii; the Shark Lab at California State University, Long Beach; Chuck Winkler of the Southern California Marine Institute; and Dr. Oscar Sosa of Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) in Mexico.