The Ministry of Natural Resources and Environment of Russia has said that 2500 dead seals have been found on the southern coast of the country.
The newspaper “The Guardian” quoted local authorities as saying that they had estimated the number of dead cells at seven hundred on Saturday.
Later, the Ministry of Natural Resources reported an increase in their number.
Officials in Russia’s Dagestan province said it was still unclear what caused the mass killings, but they were likely due to natural causes.
Information available on the number of seals in the Caspian Sea (bordered by Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan) varies considerably.
The Fisheries Agency says the total number of Caspian seals is between 270,000 and 300,000, while the Caspian Environmental Protection Center puts the number at 70,000.
The International Union for Conservation of Nature (IUCN) has included capsaicin seals on the Red List of Endangered Marine Life.
The head of the Environmental Protection Center, Zavor Gupizov, said it appears that the seals died about two weeks ago.
He added that there is no evidence yet whether they have been killed or trapped in fish nets.
Experts from the Federal Fisheries Agency have also checked the coastal area and according to the information received from there, no signs of deadly pollution were found in the water.
However, laboratory tests of the samples collected from this location are awaited.
It should be noted that there have been cases of Caspian seals being found dead in such a large number before, which have been linked to natural causes.
Kazakhstan, which has the longest coastline along the Caspian Sea, has reported at least three cases of this species this year.