1. Collaborative management of a unique fishery on the Great Salt Lake Phil Brown John Luft John Neill Kyle Stone Jim Vanleeuwen Utah Division of Wildlife Resources Great Salt Lake Ecosystem Program

2. Brine shrimp (Artemia franciscana) Zooplankton 5-10mm length Effective filter feeders 3-4 generations per year Winter die-off Produce diapausing eggs (cysts) Doyle Stephens, USGS

3. Small organisms, large role At peak 2008 densities: 5.8 shrimp/liter 94,000 tons in lake 13,400 bull African elephants 1.3 million people The only energy pathway for some important avian species Nutrient cycling Phytoplankton control NH 4 + PO 4 3-

4. Brine Shrimp Harvest Adults harvested in small numbers—1950s Expanded global aquaculture (shrimp, finfish) in 1980s led to harvest of cysts Only cysts are targeted now, collection of adults only allowed as bycatch

5. Brine Shrimp Harvest Rapid expansion in harvest—1990sRapid expansion in harvest—1990s Number of harvest companies rose from 4 to 32 by 1996Number of harvest companies rose from 4 to 32 by 1996 No state/fed wildlife agency oversightNo state/fed wildlife agency oversight Overharvest of resource was a concern for the conservationists and shrimp companiesOverharvest of resource was a concern for the conservationists and shrimp companies Recognized need for DWR regulationRecognized need for DWR regulation

6. Cooperate with companies to establish harvest limit Allow for a commercial harvest only after ecosystem needs are met First program of its kind—no one else had studied a natural brine shrimp population Great Salt Lake Ecosystem Program: 1996 to present

7. Great Salt Lake Ecosystem Program Determine harvestable surplus Understand GSL from an ecosystem perspective Required expertise outside DWR: Wayne Wurtsbaugh, Utah State University Doyle Stephens, USGS Gary Belovsky, Utah State University & Notre Dame

8. Adaptive management Began with back-of-the-envelope calculation with a 50% fudge factor….that turned out to be fairly accurate Massive data collection efforts Predictive model developed by Gary Belovsky predicts maximum cyst production Harvest allowed until cyst densities reach the cutoff 15 years of harvest without population crash Data collection and intensive monitoring continues to this day Figure courtesy of Dr. Gary Belovsky

9. Research partnerships Notre Dame—Community ecology USGS—Limnological modeling USU—Avian ecology and contaminants Westminster College—brine shrimp genetics Utah DWQ—Contaminant studies

10. Phytoplankton 60+ species 3 guilds: Green algae, cyanobacteria, diatoms Bioherms/stromatolites (Cyanobacteria) Brine ShrimpBrine Flies Eared Grebes Phalaropes Gulls Common Goldeneye PAR (sunlight) Existing nutrient pool Salinity Inflowing nutrient supply ? ? ? ? GSL foodweb gaining complexity ? ? ?

11. Still not as complex as freshwater systems Primary producers (many species) Primary consumers (12+ species) Secondary consumers (8 species) Tertiary consumers (5 species) Primary producers (60+ species) Primary consumers (2-3 species) Secondary consumers (1 part- time aquatic species, birds) Tertiary consumers (none) Lake MichiganGreat Salt Lake NOAA Great Lakes Environmental Research Laboratory Great Lakes Fishery Commission

12. Issues of concern—Water quantity Proposed Bear River diversions –250,000 acre-ft per year Proposed mineral evaporation pond expansions –350,000 acre-ft per year Nearly 20% of current river inflow Lake is already ~8 feet lower than natural state

13. Issues of concern—Water quality GSL is downstream of everything Terminal lake—substances accumulate Nutrient loading Mercury Selenium Urban runoff Pharmaceuticals

14. Watershed wide issues Stakeholders now include major municipalities and entire urban areasStakeholders now include major municipalities and entire urban areas –Loss of reciprocity: their cooperation is critical to maintaining health of lake, but they may see little to gain by it. Public perception of GSL is a problemPublic perception of GSL is a problem Few numeric water quality standardsFew numeric water quality standards

15. Questions are welcome For additional information, two manuscripts are in preparation by Dr. Gary E. Belovsky and coauthors for the following topics: Great Salt Lake aquatic foodweb and brine shrimp population dynamics: Belovsky, G.E. et al. The Great Salt Lake ecosystem (Utah, USA): long term data and a structural equation approach. Ecosphere. April 2011. Brine shrimp predictive model used for managementof harvest (in draft form)