Arctic lake fauna endangered by melting permafrost

Melting permafrost and ice is impacting the health of Arctic lakes, with serious consequences for wildlife, animal nutrition and global climate

by Lorenzo Ciotti
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Arctic lake fauna endangered by melting permafrost

A study recently published on Nature highlights how permafrost thaw in the Arctic will result in an increase in lake surface area over the next 60 to 150 years. The extent of lake area change in Arctic areas through melting permafrost has important implications for wildlife.

In fact, the appearance of thermokarst lakes changes the type of diet of the animals that live there and modifies the nesting sites of the lakes. Arctic glaciers and permafrost are melting due to global warming, a consequence of the severe climate crisis we are experiencing. Melting permafrost and ice is impacting the health of Arctic lakes, with serious consequences for wildlife, animal nutrition and global climate.

An increase in rainfall in the winter is not leading to an increase in Arctic lake area. On the contrary, the intensification of rainfall appears to be an accelerator for the permafrost thaw. The number of sites studied showing lake area expansion is nearly equal to the number of sites showing lake surface shrinkage.

This indicates that lake expansion is approximately equal to lake drainage in the area where permafrost is present.

Arctic lake fauna endangered by melting permafrost

Arctic air temperatures have risen by 2.7°C since the early 1970s and double the global average over the past two decades.

As a result of permafrost melting, there is the formation, growth and drainage of thermokarst lakes, which can exceed 40% of the land surface in some arctic lowlands. The extent of lake area change in Arctic areas through melting permafrost has important implications for wildlife.

In fact, the appearance of thermokarst lakes changes the type of diet of the animals that live there and modifies the nesting sites of the lakes. Finally, the study suggests how long-term changes in lake areas could accelerate or mitigate climate change.

The appearance and expansion of the thermokarst lake causes an increase of methane and carbon dioxide in the atmosphere. The appearance of thermokarst lakes is a common phenomenon, but studies in recent decades show that climate change is causing land flooding or drying out.

These lakes form when excessive glacier melt causes the appearance of topographic depressions, into which water can expand through mechanical erosion and lateral thermal erosion.