The volume of water in the Great Salt Lake has been reduced by more than two-thirds since pioneers once settled in the Salt Lake Valley. Much of the lake’s surface is now exposed. This fall, water levels dropped to record lows.

Photographs of empty marinas and the cracked crust of the lake’s surface often illustrate the decline of the lake. But perhaps the most worrisome symptom lies below the surface of what little water remains. The lake’s salinity levels have increased dramatically in recent years, approaching dangerous thresholds for the creatures at the base of its food web.

“As the lake sinks, the water evaporates but salts remain,” said Wayne Wurtsbaugh, professor emeritus of water sciences at Utah State University. “We are getting to the level where high salinity is stressing organisms that are adapted to that environment, mainly brine flies and brine shrimp.”

About 10 million migratory birds, some 338 species, depend on the lake’s habitat for survival.

“We could see nonlinear collapses of food webs, and that will happen before the lake disappears,” said Ben Abbott, a Brigham Young University professor who led the scientific group that warned of an emergency.

Brine shrimp are a critical food source for the aquaculture industry. Low water levels also threaten other economic commodities. The decline of the lake pushed US Magnesium, the nation’s largest magnesium producer, to apply to extend channels which are used to absorb and evaporate brine from the lake to extract the metal. The Utah Department of Environmental Quality denied his request late last year.

Meanwhile, unhealthy dust from the lake’s dry surface, containing arsenic and other heavy metals, finds its way into communities near the lake, threatening more than 2 million residents in a region already struggling with air quality.

State officials in recent years have become aware of the lake’s problem: that upstream water use chokes the terminal lake. The rivers and streams that feed the Great Salt Lake are overallocated, which means that farmers and other water users are collectively entitled to more water than normally flows each year. The amount of water that reaches the lake, particularly during a drought, is insufficient.

In the past year, lawmakers have passed several bills designed to reshape the state’s relationship with water. A bill created a water trust designed to benefit the lake and its wetlands. The Nature Conservancy and the Audobon Society were appointed to direct the trust, which received $40 million from the Legislature. Another bill makes it a «beneficial use» for farmers allow water to flow into the lake. Previously, not using all of the allocated water risked losing the future use of that water.

On the other hand, the governor of Utah, Spencer Cox, last November closed the Great Salt Lake Basin to allocations for new water useseffectively limiting the line of water users who wish to use what flows into the lake.

The recent report by scientists and conservationists says that such measures are not enough and that the impacts of those measures would take too long and that a concerted effort was needed to rescue the lake.

“The lake needs water this year,” Abbott said.

Lawmakers say they are prepared to solve the problem with new funding.

Last session, “we passed important laws that gave us the tools to help us save the lake,” said Casey Snider, a Republican state representative. «In this session, we now have the option to pull the funding levers.»

Cox, in his annual budget, included $132.9 million for the lake, incorporating $100 million for short-term water leases to «graze» agricultural water into the lake, and another $217.9 million for water supply and conservation measures in the whole state.

“We will do more than that. I’m confident. Probably a lot more,» said Utah House Speaker Brad Wilson. «There is probably no more important issue than investing in and supporting our water strategy for the lake.»