About 2,500 dead seals have been found on the coast of the Caspian Sea in southwestern Russia, conservation authorities said, a significant setback for the endangered species.
The ministry had earlier said that 700 Caspian seals were found, and then a broader count brought the total to 1,700. But “unfortunately, the figure has grown significantly and currently stands at 2,500,” the ministry said in a post on Telegram. The ministry said autopsies conducted on some of the first few hundred seals found determined that they probably died of natural causes.
Kazakhstan, one of five countries bordering the Caspian Sea — along with Russia, Azerbaijan, Iran and Turkmenistan — has on a few occasions this year reported the deaths of dozens of the seals, but not as large a number as Sunday’s toll.
The animals’ remains will be examined in a laboratory to try to establish the cause of death, the ministry said.
Zaur Gapizov, the head of the Caspian Environmental Protection Center, told the Associated Press that it was likely the seals died a couple of weeks ago and that there were no signs they were killed or caught in fishing nets.
“Any mass mortality like this is a concern,” Simon Goodman, an ecologist at the University of Leeds and an expert on Caspian seals, said in an email. He said it was important to investigate the deaths rigorously, but that doing so “often proves to be challenging in the Caspian region.”
“Unfortunately, events like this do occur fairly regularly, raising a flag that their causes and consequences need to be better understood, to guide appropriate conservation action,” he said.
Goodman said that the largest threat to Caspian seals is fatalities from being caught in illegal sturgeon-poaching gear, though habitat loss, disturbance from human activities and the effects of climate change are also concerns.
Caspian seals are the only marine mammal in the Caspian Sea and exist nowhere else in the world. Goodman said the seals are likely to have been isolated in the sea, away from other seal species, for at least 1 million years. They faced sharp population declines in the 20th century as they were hunted for their blubber and fur.
Dagestan’s Natural Resources Ministry estimated the seal’s population ranged from 270,000 to 300,000, though the Caspian Seal Project estimated it was closer to 100,000, noting that the seal is a “key indicator for the health of the Caspian Sea.” Goodman said that based on a 2005-2012 survey, the population was estimated to be around 168,000. The International Union for Conservation of Nature (IUCN) has listed the seal as endangered on its Red List of Threatened Species since 2008.
Last year, IUCN listed three areas in the Caspian Sea as “Important Marine Mammal Areas” in an effort to further conserve the population of the seals, which can grow up to 4 feet and 7 inches in length.
Russia has on occasion launched missiles aimed at Ukraine from the Caspian Sea, but there were no indications those launches had an impact on the seals.
Natalia Abbakumova contributed to this report.