At the Great Salt Lake, record salinity and low water imperils millions of birds

Utah’s Great Salt Lake is smaller and saltier than at any time in recorded history. In July, the U.S. Geological Survey (USGS) reported that the world’s third-largest saline lake had dropped to the lowest level ever documented. And last week researchers measured the highest salt concentrations ever seen in the lake’s southern arm, a key bird habitat. Salinity has climbed to 18%, exceeding a threshold at which essential microorganisms begin to die.

The trends, driven by drought and water diversion, have scientists warning that a critical feeding ground for millions of migrating birds is at risk of collapse.

“We’re into uncharted waters,” says biochemist Bonnie Baxter of Westminster College, who has been documenting the lake’s alarming changes. “One week the birds are gone from a spot we usually see them. The next week we see dead flies along the shore. And each week we have to walk further to reach the water.”

After years of inaction, the prospect of a dying lake, plus the risk of harmful dust blowing from the dry lakebed, is galvanizing policymakers to find ways to restore water to the shrinking lake.