The Beluga sturgeon has been placed on the Critically endangered list in the Caspian Sea. The Caspian Sea which is the biggest lake on Earth is bordered by Iran and Russia. The beluga sturgeon is fished for its unfertilized eggs that are used to make the World's best caviar. The high demand for the fish that creates the "best" black caviar is pushing the sturgeon to critically low numbers. The United States has banned the importation of the beluga sturgeon since 2005 as it is on the endangered species list. The decline in population numbers is seen in the other 27 species of sturgeon across the globe. In order to increase the population size of the sturgeon, scientists from the Institute for Ocean Conservation Science said focus should be placed on reducing the overfishing of the adult fish. Also, hatchery supplementation should not be relied upon to help increase the sturgeon population. Currently harvest rates are four to five times greater than the fishing levels that would maintain a stable population.