The Caspian Sea does not seem to take a break lately, given that all the recent news and views about the sea points to one environmental disaster after another; from rising pollution levels to the threat of besiegement by invasive plant species. Now, the water level is dropping.
The latest available measurement of the Caspian Sea’s water level was taken last September and put the level at -27.43 meters (relative to that of the Baltic Sea).
The Baltic Sea datum is used as a reference point to measure fluctuations in the Caspian Sea’s water level.
Some, including Morteza Eftekhari, the head of Water Research Institute, attribute the drop in water level to prolonged droughts and climate change.
However, others such as Nasser Hajizadeh, the head of the Iranian National Institute for Oceanography and Atmospheric Science, believe that more research is needed to determine whether or not the sea has been influenced by climate change, ISNA reported.
He believes it is unlikely that excessive withdrawal from the Volga River — Europe’s largest river in terms of discharge that runs through Russia and provides 85% of Caspian Sea’s water — has caused the water loss.
“Farming has always been a common practice along this river and water withdrawal is very unlikely to have changed so drastically in recent years,” he said, adding that the sea’s fluctuations are generally affected more by changes in precipitation than any other factor.
“Precipitation, inflow of rivers and evaporation are the main causes of change in the level of the Caspian Sea,” he said.
The Caspian Sea is a closed water body which was separated from the Black Sea in the Pliocene Epoch (around five million years ago) and has experienced numerous cycles of fluctuation ever since. Its area has constantly changed between one million and 150,000 square kilometers and its water level is estimated to have fluctuated within a range of over 300 meters. It experienced a massive drop in water level in the late 1970s but went back to normal in 1991. However, the water level has been gradually dropping since then.
Over the last eight years alone, the sea level dropped by 0.56 meters, and the average annual level of the sea in 2015 was -27.43 meters on the Baltic system.
The Caspian Sea is in critical condition with oil tankers alone dumping over 120,000 tons of pollutants annually. Despite discovering two major oil fields in the sea, Iran has yet to begin extracting the black gold, meaning most of the oil pollution harming the waterway is caused by the other four littoral states, namely Azerbaijan, Russia, Kazakhstan and Turkmenistan.
