The paper, “Global Catches, Exploitation Rates and Rebuilding Options for Sharks,” was recently published in the journal Marine Policy
. In the study, the researchers set out to "calculate total shark mortality and outline possible solutions to protect the world’s shark populations".
The details of the study, which was carried out by researchers from Dalhousie University in Canada, the University of Windsor in Canada, Stony Brook University in New York, Florida International University (FIU) in Miami and the University of Miami, have been featured on many news sites in recent days.
In a news release, Boris Worm, professor of biology at Dalhousie, said
“Sharks have persisted for at least 400 million years and are one of the oldest vertebrate groups on the planet. However, these predators are experiencing population declines significant enough to cause global concern.”
The researchers say the rapid decline of the shark population can be attributed to a number of factors including the boom in shark fishing and the “relatively slow growth and reproductive rates of sharks”. There is also a concern that the decline could have a negative impact on other species.
Commenting on the study, Mike Heithaus, executive director of FIU’s School of Environment, Arts and Society and co-author of the paper, said
“This is a big concern because the loss of sharks can affect the wider ecosystem.”
“In working with tiger sharks, we’ve seen that if we don’t have enough of these predators around, it causes cascading changes in the ecosystem, that trickle all the way down to marine plants.”
Boris Worm added
“Sharks are similar to whales, and humans, in that they mature late in life and have few offspring.”
“As such, they cannot sustain much additional mortality. Our analysis shows that about one in 15 sharks gets killed by fisheries every year. With an increasing demand for their fins, sharks are more vulnerable today than ever before.”
30% of shark species are threatened with extinction or near-extinction and up to 73 million are killed every year for their fins, according to statistics
from Pew Environment.