Scientists warn major sea the size of Japan is vanishing. It might be too late to save it

The Caspian Sea, which sits on the boundary of Asia and Europe, is shrinking, according to a study. Published in the journal Earth’s Future, the peer-reviewed study states that it has been receding since the 1990s. The blame can be pinned on humans and climate change. The Caspian Sea spans 371,000 square km, nearly the size of Japan and borders five countries - Russia, Azerbaijan, Iran, Turkmenistan and Kazakhstan. The researchers attribute the reason for its diminishing size to the lack of river inflow, especially from Russia’s Volga River, EarthSky reported.

Led by Jesse Duku of UC Irvine, the team of researchers studied satellite observations, river flow records and climate data to learn about the stresses. The data shows that while evaporation from the sea surface has increased, precipitation has remained largely the same since the early 1990s. However, this contributes only about 40 per cent to the problem. The biggest reason is the low flow of water from Russia’s Volga River. It has been the biggest supplier of freshwater to the Caspian Sea. But now this has changed. Also Read: Sea ice twice the size of Rajasthan goes missing from Antarctica in winter

Five major rivers feeding the Caspian Sea

Ural, Kura, Terek and Atrek are the other four major rivers that drain into the Caspian Sea. The study shows that the inflow of all five of them registered a massive dip between 1991 and 2020. The northern region has witnessed the biggest fall as it is naturally shallow. It has lost a total of 5.5 per cent of its surface area, and projections show that the levels will dip 26 to 46 feet by 2100. Also Read: Single wave as intense as 7-magnitude earthquake bounced off Earth's core and shifted Japan

Scientists also detected chlorophyll a in the northern Caspian, a type used to measure the amount of algae and cyanobacteria. The shrinking sea is threatening the ecology of the region as a consequence. The Caspian Sea is home to more than 850 species of organisms and animals that are found nowhere else in the world. The falling level of water is threatening their existence, particularly the critically endangered Caspian seal and the sturgeon. The latter provides 90% of the world’s black caviar. Also Read: Antarctica feels the heat in June as temperature soars 20 degrees Celsius above normal

Oil leaks into the Caspian

The study further states that the Caspian Sea is a major hotspot for the oil and gas industry, and approximately 1 million tons of oil leak into the waters every year. This adds to the existing stresses, influencing water quality and the ecosystem. The researchers have warned that unless all five countries come together to solve the crisis, a major environmental crisis could unfold.
Meanwhile, the American Geophysical Union says only international action can save it.