It's official: sharks in danger

Anonim

It's official: sharks in danger
A survey on shark fishing denounces the worrying decline of these predators.

A hammerhead shark (Sphyrna lewini), whose populations have decreased by almost 90 percent. © Philip Colla / OceanLight.com-Science. Click here to download the image as a background for your computer. (attention, the image is almost 70 kbytes).
A hammerhead shark (Sphyrna lewini), whose populations have decreased by almost 90 percent.
© Philip Colla / OceanLight.com-Science.
Click here to download the image as a background for your computer. (attention, the image is almost 70 kbytes).

An article in the scientific journal Science warns the international community: almost all shark species are in danger. The fishing vessels that are dedicated to the capture of sharks almost all use the longline, a fishing gear consisting of hundreds of hooks and miles of kilometers. Many species end up in this network of floating hooks, and not just those of food interest. Among the species caught, sharks are becoming very important, due to the decrease in other fish and the increase in demand for fish meats and shark fins by oriental cuisine. The result of this research, conducted by Canadian scientists from the Dalhousie University in Halifax, says that all shark species, with the exception of the mako (Isurus oxyrinchus) have decreased over the last 8-15 years by a percentage that always exceeds the 50 percent and can reach 80-90 percent, endangering marine food webs.
Massacres on the high seas. Hammerhead shark populations, for example, have fallen by at least 89 percent, and the white shark by 79 percent. The authors strongly argue that overfishing is threatening the survival of most sharks in the northwestern Atlantic. Not even closing to fishing large areas could be useful, because the fishing effort would simply have moved further, and the sharks move a great deal, ending up sooner or later in the nets. The only solution would be to close most of the Atlantic areas in front of the American coasts and decrease fishing, so as to have an ecosystem approach (that is, that keeps in mind the survival of many species), rather than trying to safeguard a species by time.

(News updated January 20, 2003)