The largest saltwater lake in the western hemisphere has hit its lowest level in almost 200 years as researchers and politicians warn of serious threats to wildlife and people on its shores.
- Almost 800 square miles of lake bed is exposed
- Exposed lake bed forms dust clouds laced with calcium, sulfur and arsenic
- Water flowing to the lake is being diverted for drinking, industry and agriculture
The surface of Utah’s Great Salt Lake hit its lowest point since 1847 on July 3, falling to an average of 4,190 feet (1,277 meters) above sea level, according to the US Geological Survey (USGS).
It is a grim milestone for the lake amid a two-decade drought.
It is expected to decrease further until autumn or early winter, when incoming water equals or exceeds evaporation.
The nearby metropolis of Salt Lake City is already subject to dust storms that experts fears could get worse.
“To save the Great Salt Lake, so that we don’t become Dust Lake City, is to make a conscious choice that the lake is valuable and that the lake needs to have water put into it,” said atmospheric scientist Kevin Perry.
For years, water that would otherwise end up in the lake has been diverted for human consumption, industry and agriculture.
Combined with the ongoing drought and exacerbated by climate change, ever more lake bed has been exposed.
The lake contains little more than one-fourth the volume of water now as it did at its high point in 1987, USGS said.
The lake has lost nearly half its surface area from the historic average, exposing some 800 square miles (2,000 square km) of lake bed — an area larger than the Hawaiian island of Maui.
Layers of earth that were formerly underwater have swirled into dust clouds laced with calcium, sulfur and arsenic, a naturally occurring element linked to cancer and birth defects.
Exposed lake bed is also contaminated with residue from copper and silver mining.
“If you breathe that dust over an extended period of time, like decades or longer, then it can lead to increases in different types of cancer, like lung cancer, bladder cancer, cardiovascular disease, diabetes and such,” Mr Perry said.
10 million birds and a multi-million-dollar industry ‘at risk’
Underwater reef-like structures host a micro-organism that is food for brine shrimp, in turn an important food for birds, but the structures dry out and turn gray when exposed.
Westminster College’s Great Salt Lake researcher Alvin Sihapanya cupped his hands in the water and showed off two palms full of water teeming with tiny shrimp.
“It’s super sad and devastating that these guys are exposed,” Mr Sihapanya said of the structures.
The National Audubon Society’s Saline Lakes Program outreach associate Max Malmquist said an estimated 10 million birds from more than 330 species migrated through or lived at the lake each year.
Half of the North American continent’s ruddy ducks stage here, while half of its redheads nest here, according to the society’s Great Salt Lake branch.
Some 90 per cent of the world’s eared grebe population stage here, feasting on the brine shrimp.
The shrimp are also harvested in a multi-million-dollar brine industry, forming part of a lake-generated economy that officials estimate to be worth up to $US2 billion annually.
With public awareness and pressure to act growing, Utah Governor Spencer Cox signed into law 11 bills related to water conservation and policy in the last legislative session.
Longer-term solutions will require major consumers in agriculture, industry, and municipalities to consume less water and give more to the lake.
“As we hit these new record lows, we start to run the risk that all of those values that we derive from the Great Salt Lake could be at risk,” said Utah State Representative Tim Hawkes.
“And that’s what’s driving this political pressure to do something.”