Mediterranean sharks: Hunters or prey
Updated: 2008-06-12 07:41
ROME: The number of sharks in the Mediterranean Sea has fallen by 97 percent in the last 200 years, putting its ecological balance at risk, says a report.
Released by the Washington-based Lenfest Ocean Program yesterday, the report used records such as fishermen's logs, shark landings, museum specimens and visual sightings to estimate the number and size of the Mediterranean sharks over the past two centuries.
There were only enough data on five of the 20 big shark species present in the Mediterranean that were useful to the study - the hammerhead, thresher, blue and two species of mackerel shark, which averaged a decline of 97 percent.
"It will have a major impact on the ecosystem because large predatory sharks are at the top of the food chain," said Francesco Ferretti, the report's lead author.
Losing the creature on top of the food chain can mean smaller fish thrive and consume more of their prey. This upsets the ecological balance. "If we lose these sharks we are going to lose this important portion of the ecosystem functioning," Ferretti said.
An International Union for Conservation of Nature report issued last month said 11 kinds of sharks faced extinction because of over-fishing, caused partly by booming demand for shark fin soup in Asia.
Fishermen all over the world catch and trade sharks for their lucrative fins, often discarding their carcasses, the report said. Indonesia and Spain are among the top culprits.
Ferretti said the practice was not thought to be common in the Mediterranean because of the small number of sharks now present there. More of a problem was "by-catch" - in which sharks are caught in long-line fishing nets meant to snag tuna and swordfish.
"Now (modern) fishing has created a big impact on the shark population,"Ferretti said.
(China Daily 06/12/2008 page1)