Magazine article USA TODAY

Populations Smaller Than Previously Thought

Magazine article USA TODAY

Populations Smaller Than Previously Thought

Article excerpt

Many shark populations around the world are known to have declined over the past several decades, yet marine scientists lack important baseline information about what a healthy shark population looks like. A clearer picture now is coming into focus--thanks to a team of scientists who investigated the size of an unfished community of reef sharks.

Researchers from the University of California, Santa Barbara, and colleagues conducted an eight-year study of a healthy shark population on Palmyra, a remote, uninhabited atoll in the central Pacific Ocean. This pristine ecosystem is part of a marine refuge that extends 50 nautical miles from its shores. No fishing is allowed within these borders, which protect a diverse array of species, including grey reef sharks. The investigators were surprised to find far fewer sharks than expected. The study results appear in the journal Scientific Reports.

"We estimated a population size of between 6,000 to 8,000 grey reef sharks at Palmyra, which works out to a density of about 20 sharks per square kilometer," says lead author Darcy Bradley, a postdoctoral researcher in the Sustainable Fisheries Group, a collaboration of the campus' Marine Science Institute and School of Environmental Science & Management. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.