ASTANA, March 13 (Xinhua) -- A total of 3,433 Caspian seals have died in Kazakhstan's Mangystau region over the past four years amid deteriorating environmental conditions in the Caspian Sea, the Kazinform news agency reported Friday, citing the Kazakh Institute of Hydrobiology and Ecology.

According to the institute, expeditionary, field and laboratory studies conducted in 2024-2025 across multiple coastal areas of the Caspian Sea found the mass deaths to be multifactorial.

Researchers said the deaths may be linked to unfavorable hydrometeorological conditions, human activities such as entanglement in fishing nets, disease and environmental pollution.

The institute said its findings had been submitted to relevant authorities for response and monitoring, warning that continued mortality could pose risks to the Caspian ecosystem and the species' long-term sustainability. The Caspian seal has been listed as endangered on the International Union for Conservation of Nature Red List since 2008. ■