Lakes are vanishing across the world (and some may never return)
Lake Poopó, Bolivia with water in 2013 (left) and dry in 2016 (right). Image: Jesse Allen/NASA
Lakes across the world are drying up, largely due to water abstraction, according to new research.
Bolivia’s second largest lake, Lake Poopó has recently dried out to become a 2,700 km2 salt pan. This dramatic loss of an important freshwater ecosystem is due to a combination of silting and water abstraction in the Desaguadero River, which feeds Poopó, and ongoing climate change (temperature have risen 0.7 degrees in the Andes over the last 70 years).
A recent article in the New Scientist brings together evidence from across the world to suggest that Poopó’s vanishing act is not an outlier event. Instead, new research suggests that lakes across the world are shrinking or disappearing – particularly in arid regions – with significant effects on the biodiversity and human populations that they support.
Research by MARS scientist Meryem Beklioğlu from the Middle East Technical University in Ankara, Turkey indicates that lakes on the Central Anatolian Plateau shrunk in size by around half between 2003 and 2010. One Turkish lake, Lake Akşehir, has completely dried up, resulting in the extinction of the Central Anatolian Bleak. Two other endemic fish species, the Eber Gudgeon and a local dace (Leuciscus anatolicus) are now critically endangered.
Many of Turkey’s lakes are shallow, which makes them vulnerable to increasing water abstraction for drinking and irrigation to meet the needs of growing populations in a warming climate. As lakes shrink, their salt levels rise and they become vulnerable to nutrient pollution and eutrophication, placing great stress onto freshwater biodiversity.
Beklioğlu uses computer models to predict how Turkish lakes will fare in the future, and suggests that at current rates of water abstraction, one of the largest lakes in the region, Lake Beysehir, will be completely dry by 2040.
Speaking to the New Scientist, she said “This water is critical for irrigation and for the local economy, but right now we are cutting off the branch we are sitting on.” To address these problems, Beklioğlu highlights the pressing need for sustainable approaches to water management in the region.
MARS scientists studying multiple stressors in Lake Beyeshir, Turkey. Image: METU Limnology Laboratory
MARS scientist Erik Jeppesen from Aarhus University in Denmark suggests that shrinking lakes across southern Europe, the Middle East and central Asia are the result of climate change and growing demand for water.
Speaking to the New Scientist, he said “This region is experiencing a drier climate now, which is also driving increased water extraction. Ultimately, the drying of the lakes along with the loss of groundwater and salinisation, will make the land less viable for agriculture in this region. This will put significant pressure on northern countries to produce more food, leading to deteriorating water quality in northern lakes due to increased fertiliser run-off entering lakes.”
The Freshwater Blog 