The tiny eggs behind the Great Salt Lake's brine shrimp harvest

Two numbers on the state's brine shrimp page are easy to read as one verdict on the Great Salt Lake. They are not. The Division of Wildlife Resources' 2026-27 harvest season opened at noon on Oct. 1. In its latest sampling run, on Oct. 19, the division counted 155.27 brine shrimp cysts per liter of lake water. In its latest harvest report, dated Oct. 21, companies had taken a cumulative 4,403,016 pounds of raw material from the lake, with none yet from the shore or salt ponds. ^[1]

The first number is a count of eggs in the water on one day. The second is a running total of what has been removed, in pounds, as of a different day. Neither one, alone or together, says whether the lake's ecosystem is secure. ^[1]

What a cyst is, and who else depends on the shrimp

Brine shrimp cysts are embryos sealed in a protective shell that can wait out harsh conditions. The harvest supplies the aquaculture industry. Commercial harvesting on the lake began in 1950, and the division says 21 companies are harvesting in the north and south arms as of 2026. ^[1][2]

The shrimp are also bird food. The division says eared grebes eat almost only brine shrimp while preparing to migrate, and its biologists measured their body mass rising from about 375 grams to about 575 grams during that staging period. Wilson's phalaropes can gain up to 2 grams a day and roughly double their weight before migration. Some other waterfowl and shorebirds also eat the shrimp, which matters most in winter when freshwater wetlands freeze. ^[2]

The shrimp in turn depend on algae. The division calls algae the primary food of brine shrimp and brine flies, and notes that algae release oxygen, which is naturally scarce in very salty water. It describes a balance among salinity, algal species and brine shrimp. ^[3]

Two measures, two calendars

Between the Oct. 7 and Oct. 21 harvest reports, the cumulative lake total rose from 1,283,159 to 4,403,016 pounds, an increase of 3,119,857 pounds. Between the Oct. 5 and Oct. 19 sampling runs, the cyst count rose from 100.46 to 155.27 per liter. ^[1]

Those pairs line up in time but not in meaning, and the state's page does not say why the count rose. A harvest total is cumulative; a sample is a snapshot. The page gives no sampling locations for this season's runs, so one run should not be read as a census of the whole lake. ^[1]

The count also needs the right yardstick. The division's current estimated minimum is 21 cysts per liter at the end of each harvest season. That is an end-of-season target, not a number every October sample is expected to approach. ^[1]

How a season ends

A paper by Gary Belovsky and W. Clay Perschon, published in 2019, describes how the fishery grew substantially in the late 1980s and how the division then managed it adaptively, building harvest models from the shrimp's biology. The authors say the harvest was successful in part because monitoring was careful and harvesting ended once a necessary reserve of cysts, called the escapement, was reached. ^[4]

Last season shows how that works in practice. In January 2026, the division extended the 2025-26 season to as late as Feb. 28, or until its staff decided cyst numbers had reached adequate levels. Its notice said the population could crash if spring cyst numbers dropped below 4 per liter or approached 80, that numbers were then near 100, and that more harvest was needed to reach the optimal 21. ^[5]

The season did not run to Feb. 28. A Feb. 2 sample of the south arm found 21.35 cysts per liter, and the division closed lake and shore harvesting in both arms at sunset, 5:52 p.m., on Feb. 6. Harvesting could continue in salt ponds. Through Feb. 4, companies had reported 40,628,672 pounds: 30,301,738 from the lake and 10,326,934 from the shore. ^[1][6]

That sequence is history, not a forecast. It does not say when this season will close.

Raw pounds, not product

State rule R657-52 requires companies to report daily and weekly harvests by raw weight. Lake-harvested loads are weighed on certified scales; shore-harvested loads are estimated. Raw pounds are not the same as finished cysts sold, so the harvest totals cannot be turned into revenue. ^[7]

The division's harvest page puts the industry's value at $10 million to $60 million, depending on the quality and quantity of cysts harvested. The rule says a harvesting certificate guarantees no minimum harvest and no particular season length. Company receipts, processing yields and export values would need other records. ^[1][7]

Why a count is not the whole story

A 17-year study of the lake, published in Limnology and Oceanography in 2019, found that the share of cysts able to hatch entering winter ranged from 17.8% to 78.8% by year, and overwinter survival from 9.9% to 65.9%. In some years, up to 39.4% hatched when the water was too cold for the young to feed, and they starved. Survival fell most in years with warmer winter water. ^[8]

A laboratory study by Belovsky and colleagues, published online in Hydrobiologia in September 2024, tested salinity, temperature and food together. Food mattered most for survival and development, and the authors concluded that studies of one factor alone have limited value. With more food, reproduction shifted from producing cysts toward bearing live young. ^[9]

The U.S. Geological Survey released a dataset on the lake's nutrients in January 2026. Its samples, from the water, lake bottom, brine shrimp, rivers and air, were collected from June through October 2020. It describes conditions then, not now. ^[10]

None of these sources measures bird numbers or feeding success this fall, or ties the harvest to any change in either. A large harvest can matter to the industry without showing the lake is recovering, and a higher cyst count can be encouraging without explaining why it changed.

Water for the lake

The Legislature's 2026 budget includes $2.8 million a year from the General Fund, under H.B. 410, to create the Great Salt Lake Preservation Program, which leases agricultural water for the lake. ^[11]