US-Canada Great Lakes turning acidic: study seeks to establish details

Subject Geography

Context:

Scientists are building a sensor network to detect the trends in the water chemistry of Lake Huron, one of the five Great Lakes of North America. It is the first step towards developing a system that would be capable of measuring the carbon dioxide and pH levels of the Great Lakes over several years.

Details:

By 2100, even the Great Lakes — Superior, Michigan, Huron, Erie, and Ontario — might approach acidity at around the same rate as the oceans.

Acidification of water bodies:

Acidification of oceans or freshwater bodies takes place when excess carbon dioxide in the atmosphere gets rapidly absorbed into them.
Scientists initially believed this might be a good thing, as it leaves less carbon dioxide in the atmosphere. But in the past decade or so, it has been established that absorption of carbon dioxide leads to a lowering of the pH, which makes the water bodies more acidic.
According to the National Oceanic and Atmospheric Administration (NOAA) of the US government, ocean water has become 30 per cent more acidic in the past 200 years.

Consequences of acidification:

The five lakes would witness a pH decline of 0.29-0.49 pH units — meaning they would become more acidic — by 2100.
Acidification may lead to a decrease in native biodiversity, create physiological challenges for organisms, and permanently alter the structure of the ecosystem.
It would also severely impact the hundreds of wooden shipwrecks that are believed to be resting at the bottom of these lakes.
As per research, their pH levels had declined three times faster in 35 years than in oceans since the Industrial Revolution. This may result in the loss of some species.
As a result of the increase in acidity the ability of water fleas to defend themselves against predators was compromised.

About the Great Lakes:

The Great Lakes are five interconnected bodies of water straddling the US-Canada border that drain into the Gulf of St Lawrence in the North Atlantic through the St Lawrence River.
These five lakes form the largest group of freshwater lakes on Earth by total area and the second largest by total volume containing 21% of the world’s surface freshwater by volume.
The US-Canada border passes through Lakes Superior, Huron, Erie, and Ontario while Lake Michigan lies entirely in the US.
Lakes Michigan and Huron are sometimes considered as a single water body.
- Taken together, they are the world’s largest freshwater lake by surface area.
By itself, Lake Huron is the world’s third-largest freshwater lake, after Lake Superior (one of the five lakes, and the world’s largest freshwater lake) and Lake Victoria.

Significance of the Great Lakes:

The Great Lakes are believed to have been born some 20,000 years ago, when the Earth started to warm and water from melting glaciers filled the basins on its surface.
They contain a fifth of the world’s total freshwater and are a crucial source of irrigation and transportation.
They serve as the habitat for more than 3,500 species of plants and animals.