Moscow (AsiaNews/Agencies) - The sturgeon of the Caspian Sea, which provide about 90 percent of the world's caviar, are at risk of going extinct in about a decade, unless there are precise limits on fishing and on pollution.  But the outlook is grim, because in the past fishermen have always violated the established limits.

The annual "catch" is of about 1,000 tonnes of sturgeon.  Now the coastal countries (Russia, Kazakhstan, Turkmenistan, Iran, and Azerbaijan) are discussing a moratorium, promoted mostly by Moscow, which wants a general ban by the beginning of 2009.  But in order for this to be effective, alternative sources of income have to be found for thousands of families that depend on fishing, in economically depressed areas where there is systematic poaching because of the lack of supervision by authorities.  Poachers even use explosives to catch more fish faster, with serious damage to the entire environment.

In fact, the stocks of sturgeon have been falling since the beginning of 1991, after the fall of the Berlin Wall.  In 2006, the Convention on International Trade in Endangered Species, a UN agreement, placed a ban on the export of caviar by these countries (except for Iran), but experts have commented that this only encouraged the black market.

Now Moscow wants to use "tough tactics": in April, Russia tightened its controls in the region of  Astrakhan, and prosecuted 28 poachers.  But sources in the area say that authorities and local supervisors often accept fish and caviar in exchange for looking the other way.

Another serious problem is created by the companies that dig up the sea floor in search of oil and gas, without attending to the damage, which is not so much caused by the digging as by its byproducts, like the emissions of hydrogen sulfide, which is deadly to marine life.  For example, in 2001 it killed at least 250,000 tonnes of sprat, a small fish eaten by the sturgeon, which have now disappeared from the Caspian.  In 2011, production will begin at the giant oil deposit of Kashagan, in Kazakhstan, the extraction of which will produce immense quantities of hydrogen sulfide.