Editing Great Salt Lake (section)

==Commerce==
[[File:Great Salt Lake, Utah USA (2006).jpg|thumb|upright|Solar evaporation ponds in the Northeast portion of the lake. Fremont Island is visible to the South (top of image)]]

Great Salt Lake contributes an estimated $1.3&nbsp;billion annually to [[Economy of Utah|Utah's economy]],<ref name="SLTrib Causeway">{{cite news |url = http://www.sltrib.com/sltrib/news/54989110-78/causeway-lake-salt-corps.html.csp |title = Great Salt Lake causeway sinks, prompting emergency repairs |first = Judy |last = Fahys | publisher = The Salt Lake Tribune |access-date = November 21, 2012 |archive-date = November 2, 2012 |archive-url = https://web.archive.org/web/20121102172456/http://www.sltrib.com/sltrib/news/54989110-78/causeway-lake-salt-corps.html.csp |url-status = live }}</ref> including $1.1&nbsp;billion from industry (primarily mineral extraction), $136&nbsp;million from recreation, and $57&nbsp;million from the harvest of brine shrimp.<ref name="Economic powerhouse">{{cite news |url = http://www.sltrib.com/sltrib/politics/53568160-90/advisory-brine-economic-lake.html.csp |title = Great Salt Lake an economic powerhouse for the state |first = Judy |last = Fahys | publisher = Salt Lake Tribune |access-date = October 28, 2013 |archive-date = November 10, 2016 |archive-url = https://web.archive.org/web/20161110092731/http://www.sltrib.com/sltrib/politics/53568160-90/advisory-brine-economic-lake.html.csp |url-status = live }}</ref>

===Brine shrimp===
The harvest of brine shrimp cysts during fall and early winter has developed into a significant local industry, with the lake providing 35% to 45% of the worldwide supply of brine shrimp,<ref name="Economic powerhouse"/> and cysts selling for as high as {{convert|35|$/lb|$/kg}}.<ref name="SLV Leap of Faith">{{cite web|url = http://www7.nationalgeographic.com/ngm/data/2002/02/01/html/ft_20020201.5.html|title = Salt Lake Valley's Leap of Faith |first = Lisa Moore |last = LaRoe | publisher = National Geographic |access-date = August 11, 2006 |archive-url = https://web.archive.org/web/20071011182139/http://www7.nationalgeographic.com/ngm/data/2002/02/01/html/ft_20020201.5.html |archive-date = October 11, 2007 |url-status = dead}}</ref> Brine shrimp were first harvested during the 1950s and sold as commercial fish food. In the 1970s, the focus changed to their eggs, known as cysts, which were sold primarily outside the US as food for shrimp, prawns, and some fish.<ref name="USGS shrimp"/> Today, these are mostly sold in [[East Asia]] and [[South America]].<ref>{{cite web |url = http://www.wildlife.utah.gov/gsl/brineshrimp/southarm.html |title = South Arm (Gilbert Bay) |publisher = Utah Division of Wildlife Resources |access-date = August 12, 2006 |archive-date = July 13, 2006 |archive-url = https://web.archive.org/web/20060713072843/http://www.wildlife.utah.gov/gsl/brineshrimp/southarm.html |url-status = live}}</ref> The amount of cysts and the quality are affected by several factors, but salinity is most important. The cysts will hatch at 2 to 3% salinity, but the greatest productivity is at salinities above about 10%. If the salinity drops near 5% to 6%, the cysts will lose buoyancy and sink, making them more difficult to harvest.<ref name="USGS shrimp"/>

The causeway across the lake was built in the 1950s as a replacement to a wooden trestle.{{r|DNews Causeway}} Prior to December 2, 2016, the causeway constrained the flow of water between northern and southern arms, which has a significant impact on various industries surrounding the lake. The construction of a {{convert|180|ft|m|adj=mid|-long}} bridge created an opening of the causeway for water to flow between the arms of the lake.

The northern arm of the lake has a much higher salinity, to the point that the native [[brine shrimp]] cannot survive in its waters. In the southern portion of the lake, where the vast majority of the fresh water inlets are found, the salt level can dip below what is necessary for the brine shrimp to survive. With the opening of the bridge, the salinity of the northern arm of the lake will likely drop as less saline water from the southern arm of the lake flows into the northern arm. The brine shrimp harvesting industry could benefit from the freer flow of water.<ref name="SLTrib Causeway"/> There were concerns from the brine shrimp harvesting industry that the conditions in the southern arm of the lake were becoming too saline for the brine shrimp, following several years of lower precipitation in the lake's watershed. The precipitation in the watershed was above normal for the water year beginning on October 1, 2016. The additional water allowed the levels of both arms of the lake to rise,<ref name="usgs-water-data-20160430-20170430" /> creating better conditions for a healthy brine shrimp population.

===Oil and minerals===
Great Salt Lake Minerals Company (a subsidiary of [[Compass Minerals]]) extracts minerals from the northern bay. The company potentially benefited from the higher salinity of the north-west arm of the lake but had difficulty accessing water from the lake because of lower water level. Prior to the opening of the causeway, the intake channels had to be extended to reach the water.

[[Morton Salt]], [[Cargill Salt]], Broken Arrow Salt and the [[Renco Group]]'s U.S. Magnesium each extract minerals from the southern bay and could benefit from a more natural mixture of water between the two sides of the lake.<ref name="DNews Causeway" /> US Magnesium operates a plant on the southwest shore of the lake, which produces 14% of the worldwide supply of magnesium, more than any other North American magnesium operation.<ref name="Economic powerhouse"/> Mineral-extraction companies operating on the lake pay [[royalties]] on their products to the State of Utah, which owns the lake.<ref name="UGS Salt">{{cite web |url = https://geology.utah.gov/popular/great-salt-lake/commonly-asked-questions/#toggle-id-25 |title = What minerals are produced from Great Salt Lake? |publisher = Utah Geological Survey |access-date = August 26, 2023 |archive-date = November 8, 2010 |archive-url = https://web.archive.org/web/20101108155232/http://geology.utah.gov/online/PI-39/pi39pg11.htm |url-status = live }}</ref>

Solar evaporation ponds at the edges of the lake produce [[salt (chemistry)|salt]]s and [[brine]] (water with high salt quantity). Minerals extracted from the lake include: [[sodium chloride]] (common salt), used in [[water softening|water softeners]], [[salt lick]] blocks for livestock, and to melt ice on local roadways (food-grade salt is not produced from the lake, as it would require costly processing to ensure its purity); [[potassium sulfate]], used as a commercial fertilizer; and [[magnesium chloride|magnesium-chloride]] brine, used in the production of [[magnesium]] metal, [[chlorine gas]], and as a dust suppressant.

The lake's north arm contains deposits of oil, but it is of poor quality and it is not economically feasible to extract and purify it.<ref name="DN-Tales"/> As of 1993, approximately {{convert|3000|oilbbl|m3}} of [[crude oil]] had been produced from shallow wells along the shore.<ref>{{harvp|Hassible|Keck|1993|p= 20}}.</ref> The oil field at Rozel Point produced an estimated {{convert|10000|oilbbl|m3}} of oil from 30 to 50 wells, but has been inactive since the mid-1980s. Oil seeps in the area had been known since the late 19th century, and attempts at production began in 1904.<ref>{{cite web|url = http://geology.utah.gov/surveynotes/geosights/rozelpoint.htm|title = 'Bubblin' Crude' at Rozel Point, Box Elder County, Utah |first = Mark |last = Milligan |publisher = Utah Geological Survey |access-date = November 21, 2012 |archive-date = March 23, 2011 |archive-url = https://web.archive.org/web/20110323204429/http://www.geology.utah.gov/surveynotes/geosights/rozelpoint.htm |url-status = live}}</ref> Industrial debris from this field remained in place near ''[[Spiral Jetty]]'' until a cleanup effort by the Division of Oil, Gas and Mining and the Division of Forestry, Fire, and State Lands was completed in December 2005.<ref>{{cite web |url = http://geology.utah.gov/surveynotes/geosights/rozeljetty_revisited.htm |title = Rozel Point and ''Spiral Jetty'' Revisited, Box Elder County, Utah |first = Mark |last = Milligan |publisher = Utah Geological Survey |access-date = November 21, 2012 |archive-date = August 27, 2013 |archive-url = https://web.archive.org/web/20130827221644/http://www.geology.utah.gov/surveynotes/geosights/rozeljetty_revisited.htm |url-status = live}}</ref>