The IPEE RAS expedition has returned from the Dagestan coast of the Caspian Sea with collected materials to find out the reasons for the mass mortality of Caspian seals.
At the beginning of December 2020, the first information about Caspian seals stranding on the Dagestan coast appeared (the species is listed in the Red Data Book of the Russian Federation). Nataliya Shumeyko, Head of Kaspika Caspian Seal Conservation Agency, employee of A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IPEE RAS), left for the area of stranding after the very first messages on it. Financial support for the expedition was provided by IPEE RAS partners – NCOC N.V. and LLP “Kazakhstan Agency of Applied Ecology”.
The researches in Dagestan were organized jointly with Magomedrasul D. Magomedov, Chief Researcher at the Caspian Institute of Biological Resources of the Dagestan Scientific Center of the Russian Academy of Sciences (CIBR DSC RAS) and Irina Suvorova, Senior Veterinarian at Moskvarium Center for Oceanography and Marine Biology. Later, when it became known about the seals died in the fishing nets, employees of the All-Russian Research Institute of Fisheries and Oceanography (VNIRO) joined the expedition of the IPEE RAS, PIBR DSC RAS and Moskvarium. This helped to expand the range of researches.
For molecular-virological, toxicological, hormonal, genetic, histological and morphological studies, the samples of biological material were taken from 13 dead seals. These animals were mainly adult females – five of them were pregnant. One of 13 animals was damaged in fishing net.
In addition, the members of the expedition monitored dead seals at 10 sections of the sandy coast with a total length of 30 km, where over 300 dead seals were found. All the found animals were photographed. The GPS-coordinates of their location were recorded – that will be used to create a map of stranding. Extrapolation of the obtained data shows that about two thousand seals can be thrown onto sandy beaches, the length of which along the Dagestan coast of the Caspian Sea is 160 km (the average occurrence is more than a dozen individuals per kilometer of the Dagestan coastline).
The data received by now is not sufficient to form a hypothesis about the reasons for the death of such a large number of Caspian seals. All collected samples will be transferred for research to various laboratories, and the efforts of various organizations will be combined to find out the cause for the death of Caspian seals.
The coast near Makhachkala. In the photo (from left to right): Nataliya R. Shumeiko, Head of Kaspika Caspian Seals Conservation Agency, employee of IPEE RAS; Magomed M. Magomedov, Chief Researcher at PIBR DSC RAS; Irina V. Suvorova, Senior Veterinarian at Moskvarium Center for Oceanography and Marine Biology; Shamal M. Nasimov, First Deputy Prosecutor of the Makhachkala Interdistrict Environmental Prosecutor’s Office.