Mediterranean sharks see 99% decline, now "functionally extinct"

Just a few weeks after six shark species were added to the IUCN Red List of Endangered Species, a new study says that shark populations in the Mediterranean have declined a shocking 99% over the last two centuries, putting the entire Mediterranean ecosystem at risk.

The study, published this week in the journal Conservation Biology, analyzed population trends for five species and found that their numbers have dropped between 96 and 99.99% from historic levels. The authors place the blame solely on human activity, specifically overfishing.

Species affected by this dramatic loss include hammerhead (Sphyrna spp.), blue (Prionace glauca), mackerel (Isurus oxyrinchus and Lamna nasus), and thresher sharks (Alopias vulpinus). Hammerheads have not been seen in the Mediterranean for at least 13 years.

At least 15 other species considered for the study did not have sufficient historic records to be examined thoroughly.

According to the authors of the study, "So far, the lack of quantitative population assessments has impeded shark conservation in the Mediterranean Sea. Our study fills this critical information gap, suggesting that current levels of exploitation put large sharks at risk of extinction in the Mediterranean Sea. Possible ecosystem effects of these losses involve a disruption of top-down control and a release of midlevel consumers."

Lead author Francesco Ferretti of Dalhousie University told The Daily Telegraph that large sharks were considered pests by fishermen, who may have killed them off to keep fish populations higher.

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