During an expedition to the shores of the Caspian Sea within the Republic of Dagestan in May, changes in the coastline, beaches, cliffs, and aeolian forms of the Caspian coast were studied. The expedition was organized by the Southern Branch of the P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences as part of the Russian Science Foundation project 25-17-00104, "Development of Large Coastal Accumulative Forms of the Southern Non-Tidal Seas of Russia under Changing Natural and Anthropogenic Factors," with the active participation of the Dagestan State Nature Biosphere Reserve.

The aim of the research was to study the structure and dynamics of the relief elements of accumulative coastal forms of the Caspian coast under conditions of sharp changes in sea level.

Incision of a river channel into coastal marine sediments
as a result of falling sea levels and extreme flooding,
the mouth of the Artuzen River

Scientists carried out a route survey of test areas within the Agrakhan Peninsula (new delta of the Terek River and Chechen Island); in the area of ​​Novokayakent (the mouth area of ​​the Artusen River near Lake Papas); in the delta region of the Samur River. As a result of the work carried out, current information was obtained on the morphometric characteristics of landforms, vegetation, the condition and composition of sediments of various origins, the course and consequences of extreme natural phenomena.

The collected materials from the expedition's research still need to be processed and analyzed. However, the scientists were able to draw some preliminary conclusions based on the data obtained.

The consequences of the general decline in the Caspian Sea level are noticeable everywhere.

A section of the dried-out strait bed between the Agrakhan Peninsula and Chechen (now ex) Island is covered with a carpet of flowering grasses. At the same time, desertification is occurring in the higher elevations—many plant species are disappearing, and the dunes are beginning to move again.

At river mouths, the lowering of the erosional base resulted in a sharp intensification of erosion processes, significantly exacerbated by numerous and prolonged floods. For example, the cordon on the banks of the Terek River, where the expedition was based, no longer exists. In turn, the erosion of river banks contributed to the influx of enormous quantities of solid sediment into the coastal zone, leading to an increase in the area of ​​the deltas.

"Natural mechanisms are much more complex than we imagine. The causes of sea level decline remain a highly debated topic. Even more mysterious is the cause of the Caspian Sea level rise observed at the end of the 20th century. Consequently, predicting a new rise is currently impossible—and it could begin literally at any moment. Meanwhile, the entire coastal strip of the sea and the adjacent dried-up lagoons are being frantically built up—without any consideration of the possible consequences," noted Marina Krylenko, PhD in Geography and head of the Laboratory of Lithodynamics and Geology at the Southern Branch of the Shirshov Institute of Oceanology of RAS and head of the expedition.

Drainage strip near the mouth of the Samur River

The dried-up bottom of the Caspian Sea in the north of Chechen Island

Lighthouse on Chechen Island

The dry bed of the strait between the Agrakhan Peninsula and Chechen Island

Aeolian forms on the Agrakhan Peninsula

The geobotanical description is being carried out
by DSc Ramazan Murtazaliev (Caspian Institute of Biological Resources,
Dagestan Federal Research Center of RAS)