Caspian Sea 2011

2010

geons and thus, in a single tonne, there are far more specimens compared to other species. Stel- late constituted about 30 per cent of the total sturgeon catch in the Caspian in the 1970s and 1990s, but dropped to about 20 per cent of the total in 2004. The decline in the Stellate sturgeon stock is most notable in the Ural Basin where, in 1990, it comprised 75 per cent of the commercial sturgeon catch. The total official Stellate catch in 2008 was only 90 tonnes. Small amounts of Bastard sturgeon or Ship ( Aci- penser nudiventris Lovetsky, 1828) have traditionally been found in the Caspian. Its total annual catch never exceeds 100 tonnes and it represents only 1 per cent or less of the total sturgeon catch. It seems population levels of Ship sturgeon are mo­ re or less stable, limited to the Ural River, where commercial catch of Ship is prohibited. On top of that, Kazakhstan grows juvenile Ship and re- leases it into the sea. Iran has continued its com- mercial catching until now.

The structure of sturgeon catches has changed over the years. In recent times, Persian sturgeon has played a more important role due, in large part, to the drastic reduction in catches of other species, however there are no verifyable data on the structure of Iranian catch. The main reasons behind the serious decline in these bioresources over the years were initially believed to be the reduction in spawning grounds (WB 2008), illegal fishing in the post-Soviet era and oil and gas development in the region (CEP 2007a). The construction of several dams along spawning rivers (mainly the Volga River) signifi- cantly altered water flows and destroyed about 90 per cent of the sturgeon’s spawning grounds (UNEP/GRID-Arendal 2006). Now, only the Ural River provides spawning opportunities unaffected by dams - and is able to support long-distance spawning migration. But nevertheless, the most up-to-date analysis reveals that insufficient and ineffective control over catches of sturgeon is now the most critical factor depressing sturgeon stocks (WB 2008). Also because of the illegal stur- geon catches in number of countries have raised between 1998 and 2006 (WB 2008). According to experts, the poaching are recently shifted from the territory of Russia to Kazakhstan in the north- ern part of the Caspian Sea. Kazakhstan waters and its territories are under pressure from poach- ers from Azerbaijan, Kazakhstan and Russia. Tulka (kilka) stock collapse Three endemic species of tulka are recognized in the Caspian Sea: Clupeonella caspia – (Caspian tulka/common tulka); Clupeonella grimmi (Southern Caspian or Big-eye tulka), and Clupeonella engrau- liformis (Anchovy tulka) (UNDP 2009b). Each spe- cies has its own peculiarities in terms of distri- bution, food preference, spawning time and other biological and ecological characteristics (UNDP 2009b). Tulka catches dramatically changed over the period 1970-2008 in all countries. Over a 20- year period, starting in 1970, catches decreased annually in Azerbaijan, Turkmenistan, Kazakh- stan, and Russia. The total tulka catch declined from 410 thousand tonnes in 1970 to 132 thou- sand tonnes in 1996. A temporary tulka catch re-

Collapse of Tulka in the Caspian

Catches, thousands of tonnes

Azerbaijan Iran

400

Russia Turkmenistan Total Kazakhstan

300

200

100

0

1960 1970 1980 1990 2000 2008

1930 1940 1950

Source: personal communication with Igor Mitrofanov

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