Conservationist group WWF on Tuesday urged Romania and Bulgaria, home to the last viable wild sturgeon populations in the European Union, to protect the species, threatened by illegal fishing and caviar trade.

"Sturgeon is a species threatened by overfishing, by the pressure of the caviar market and by infrastructure projects that hamper its migration up the Danube", WWF Romania programme director Magor Csibi told a press conference.

Csibi said that despite a 10-year sturgeon fishing ban imposed by Romania in 2006, followed by Bulgaria in 2011, poaching continues, especially in the Danube Delta, where the local economy depends on fishing.

"Romania and Bulgaria are home to the only viable wild sturgeon populations left in the European Union, but unless this sophisticated illegal fishing is stopped, these fish are doomed," said WWF's Jutta Jahrl, author of a new report conducted jointly with TRAFFIC, a wildlife trade monitoring network.

The survey conducted on 30 caviar samples collected from shops, restaurants and street vendors from Romania and Bulgaria "demonstrates that caviar allegedly from wild sturgeons is still being offered for sale (in the two countries) despite the current ban."

"This is the 11th hour, if we do not take steps to restore wild sturgeon populations there will be no sturgeon left for our children and grand-children," Romania's junior environment minister Lucia Varga said.

WWF figures show that sturgeon catches dropped in Romania from 1,144 tonnes in 1940 to just eight tons in 2005, before the ban was imposed.

Romania was among the world's top five caviar exporters, with 26 tonnes exported between 1998 and 2006, according to WWF-TRAFFIC.

After unilaterally deciding to stop exports in 2006, it hopes to one day restart exporting farm-raised caviar.