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Show There was a massive redistribution of salt between the north and south arms when the state breached the railroad causeway in 1984. And, during 1987- 1989, the state pumped over 600 million tons of salt out of the north arm of the lake as a result of WDPP. WDPP removed 12 to 14 percent of the total salt load of the lake, much of which has not been returned to the lake but remains out in the West Pond. The natural precipitation of salt on the bottom of the lake during low- lake periods can temporarily sequester large amounts, perhaps as much as 25 percent. These actions have also had an impact on the salinity distribution within the lake as a whole. Increasing the return of salts from the north to the south arm would restore salts to the south. The results of ongoing research by various state, federal and private entities will provide answers as to how changes in the lake will produce changes in its ecology. The salinity of GSL is composed of different ions. Brine shrimp ( focus species) have many different life requirements over the course of their existence. Historical experience has suggested that brine shrimp and cyst production is best when salinities are between 12- 18 percent. When salinities are outside this range, shrimp population productivity is substantially diminished. The following impacts to shrimp may occur: lower absolute cyst production, lower cyst quality and higher susceptibility to disease and poor nutrition, among others. All of these impacts can occur from the interrelationships of food abundance/ quality, predation, water chemistry and other habitat- related constraints. Given the increasing attention to salinity- related issues, DNR believes it is important to know the locations and amounts of salts. Some locations may hold relatively small quantities. An accounting of all salts in the lake, regardless of where they are, will serve as a baseline for future studies and/ or inventories. DFFSL will consult with affected landowners and mineral operators regarding the approach to accounting for salts. 2.3 Other water chemistry topics A better understanding of lake chemistry will provide the fundamental information necessary to understand and optimize the many uses of the lake now and in the future. UGS currently has a brine- chemistry database which was started in 1966 and continues to the present time. Parameters include major ions ( sodium, potassium, magnesium, calcium, chloride and sulfate) and minor elements ( lithium, bromine and boron). Other parameters include field and lab densities, temperature and secchi- disk readings. These elements/ metals are of interest to the mineral extraction industries. In addition to these data, DWQ, in cooperation with the Health Department, has analyzed the lake brines for nutrients, metals and other components. The state has a good database on the salinity, chemistry and other parameters of the lake. Many of the trace component distributions and concentrations are somewhat unknown and available data is limited. These components are often paramount to the overall water quality, bioconcentrate and have profound effects on various life forms at every level in an aquatic system. These components include iron, zinc, copper, fluoride, 292 |