Among the sturgeon species native to the Danube basin is the Beluga sturgeon, which is famous for its expensive caviar. Beluga sturgeons spawn in the gravel banks of the Lower Danube and migrate downstream to spend the rest of the year in the Black Sea. Until the 19th century, giant Beluga sturgeons migrated from the Black Sea up the Danube as far as Germany and were important mainstays for many fishing communities, but today, this ancient fish is on the brink of extinction.
The Atlantic sturgeon (Acipenser sturio) is already extinct, while the Ship sturgeon (Acipenser nudiventris) is close to extinction. The Danube sturgeon (Acipenser gueldenstaedti), the Beluga (Huso Huso) and the Stellate sturgeon (Acipenser stellatus) are highly endangered and extremely rare, while the Starlet (Acipenser ruthenus) is dependent on stocking programmes for survival.
Sturgeons can become very old and are sexually mature at a late age; the Beluga reaches sexually maturity at the age of 15. During the spawning season, from spring to summer, sticky, brownish-green eggs are laid. After 2 weeks, the young sturgeon are ready to feed, and they migrate to the ocean between their 1st and 3rd years.
On the brink of extinction
Sturgeons have outlasted the dinosaurs, but now five of the six iconic fish species in the Danube basin are teetering on the brink of extinction due to impacts of human activities. Dams that block the migration routes of sturgeons, the loss of spawning habitats and overexploitation of the fish, driven by caviar consumption, are the main human activities that threaten and impact sturgeon populations.
In 2011 Bulgarian authorities announced a one-year ban, joining the efforts of neighbouring Romania, which imposed a ban for the period 2006-2016.
Conservation of Danube Sturgeons
Sturgeons are important to conserve not only for their economic value, but also for their place in evolution, their fascinating life-cycle and role as indicators of healthy river ecosystems. The complex marine-freshwater life-cycle of these ancient creatures and, at the same time, high value to the fishing industry, make these fish especially vulnerable to impacts from human activities. To help Danube Sturgeons, it would be useful to:
Secure critical spawning habitats.
Initiate action to halt illegal fishing and trade of Danube sturgeons.
Initiate action to restore migration routes across the Iron Gates Dams.
WWF is working with the International Commission for the Protection of the Danube River (ICPDR) and the governments of Serbia and Romania to explore the feasibility of making the Iron Gates Dams passable to sturgeon and other migrating freshwater species, effectively doubling their Danube range.