Documents

The Caspian Sea, world largest lake, is bordered by Azerbaijan Republic, Islamic Republic of Iran, Kazakhstan, Republic, Russian Federation and Turkmenistan. Its biodiversity is comprised of 1354 plant, animal and more than 122 fish species. Out of 122 fish species and subspecies living in the Caspian Sea, 40 species are commercial and presently 25 species are the main exploited fish. The Caspian Sea fishes are divided to four main groups, including 53 species Marine fishes (43.5%), 42 species (13.4%) of freshwater origin, 18 species (14.7%) anadromous and 9 species (7.4%) semi-anadromous. At present sturgeons, kilka and Caspian Sea seals are considered as shared stocks between Caspian Sea range states.

The article examines recent Caspian Sea level change by using both satellite radar altimetry and satellite gravity data. The altimetry record for 2002–2015 shows a declining level at a rate that is approximately 20 times greater than the rate of global sea level rise. Seasonal fluctuations are also much larger than in the world oceans. With a clearly defined geographic region and dominant signal magnitude, variations in the sea level and associated mass changes provide an excellent way to compare various approaches for processing satellite gravity data.