Beluga  (Huso huso)

Classified as Endangered (EN - A2d) on the IUCN Red List 2002. Listed on Appendix II of CITES and Appendix II of the Convention on Migratory Species (CMS or Bonn Convention) (1).

The beluga is the largest sturgeon in the world and the largest European freshwater fish; it can reach up to 5 metres in length (3). This ancient fish has an elongated body shape and a flattened, slightly upturned snout (2), with the mouth located underneath (4). There are five rows of bony plates (or 'scutes') that run the length of the body, one along the back, one on each flank and two on the undersurface (2). The short, fleshy barbels in front of the mouth are feathered at the ends (3). The body is predominantly dark grey or greenish whilst the belly tends to be white (2).

Found in Europe, principally in the Caspian Sea with spawning occurring mainly in the Volga River (5). Beluga are also found in and around the Black, Caspian and Azov Seas as well as the Adriatic (3).

Belugas are anadromous fish, spending most of their life at sea but migrating to fresh water in order to spawn (4).

These large fish can take up to 18 years to reach sexual maturity and even then will only spawn once in every 2 to 4 years (3). Adults migrate upstream in the spring or autumn to spawn in shallow pools; a single female can produce between 300,000 and 7.5 million eggs, which are attached to stones on the pool floor (3). Once they have emerged, juveniles migrate downstream to the sea (3).

The fleshy barbels in front of the mouth are used to search for prey on the seafloor and riverbed (6); juveniles feed mainly on small invertebrates whereas adults tend to consume fish such as anchovy, gobies and herring (3). Belugas spend the majority of their time in the lower reaches of the water column, near to the substrate (2).

Sturgeon have survived since the time of the dinosaurs but some populations of the beluga are today threatened with commercial extinction, principally as a result of overfishing (5). The eggs are highly prized as caviar, for both their quality and quantity (4). The beluga is the most famous of the caviar sturgeons, and is featured in the Guinness Book of Records as the most expensive fish (2). Previously effective management of Caspian Sea fisheries have recently collapsed and illegal fishing is now rife; the U.S Fish and Wildlife Service estimated in 1998 that more than 50% of worldwide caviar trade was illegal (5). In addition, habitat destruction through the pollution of coastal habitats and the alteration of river systems through dams, pollution and silting have further affected beluga numbers (4). The Volgograd Dam for example, has blocked almost all beluga spawning grounds (5).

The Convention on International Trade in Endangered Species (CITES) (7) imposed a six-month ban on sturgeon catches in June 2001, but conservationists are concerned that this has not gone far enough to save the beluga sturgeon (8). The majority of the sturgeon population is now supported artificially (9); hatcheries may be the sole reason belugas still persist in the Caspian Sea (5). The United States is the biggest importer of caviar and the Fish and Wildlife Service is currently considering listing the species under the Endangered Species Act, effectively banning importation (8), but time is running out in the fight to save this ancient fish

Caviar Emptor:
http://www.caviaremptor.org/

Authenticated (13/8/03) by John Waldman, Hudson River Foundation.
www.hudsonriver.org

• Anadromous: in fish: those species that spend most of their lives at sea but migrate to fresh water to spawn.
• Barbels: fleshy projections near the mouth of some fish.
• Invertebrate: animals with no backbone.

1. UNEP-WCMC database (August, 2002) www.unep-wcmc.org
2. Fishbase (September, 2002) http://www.fishbase.org/Summary/SpeciesSummary.cfm?genusname=Huso&speciesname=huso
3. Cihar, J. (1991) Freshwater Fish. Aventinum Publishing, Prague.
4. Paxton, J.R., Eschmeyer, W.N. [eds.] (1994) Encyclopedia of Fishes. University of New South Wales Press, Sydney.
5. Natural Resources Defence Council, Wildlife Conservation Society, SeaWeb (Dec, 2000) Roe to Ruin: The Decline of Sturgeon in the Caspian Sea and the Road to Recovery. Available at: http://www.caviaremptor.org/roe_to_ruin.PDF
6. Nelson, J.S. (1984) Fishes of the World [2nd edn.]. John Wiley & Sons Inc, New York.
7. CITES (September, 2002) http://www.cites.org/
8. Caviar Emptor (September, 2002) http://www.caviaremptor.org/
9. Caspian Environment Programme (September, 2002) http://www.caspianenvironment.org/