Lake Superior

An accompanyiag effect of eutrophication that is more readily observable ia Table 1 is a decrease ia siUca coaceatratioa ia Lake Oatario. Some decliae ia dissolved siUca appareatiy has occurred ia all of the lakes except Lake Superior. This decliae is brought about by the growth of diatoms, a species of aquatic microorganisms ia the upper layers of lake water that is widespread ia all types of water impouadmeats where the water is clear and exposed to the sun. The siUca is used by these microorganisms to form their skeletons and is later precipitated and becomes part of the bed sediment. 

A major portion of our water-based recreational activities occurs in the tliousands of lakes, reservoirs, and otlier small, relatively quiescent bodies of water. The ecosystems of lakes tlu-oughout tlie world are of primary concern in water qiuility management. The lakes and reservoirs vary from small ponds and dams to the magnificent and monumental large lakes of tlie world such as Lake Superior (one of the Great Lakes) and Lake Btiikal in tlie Soviet Union, the deepest lake in the world (1620 m 53 lO ft). 

The Great Lakes have suffered the invasion of numerous exotic species of which the smelt, alewife and sea lamprey are probably the best known. More recently, two more species have entered the lakes probably via ballast water from foreign ships. The ruffe (Gymnocephalus cemuus) a small percid, feeds on the eggs and larvae of other percids and whitefish. The ruffe is currently considered to be a threat to Lake Superior s 5- 10 million whitefish fishery. The zebra mussel (Dreissena polymorpha) was discovered in Lake St. Clair in 1985 (31). It has subsequently been discovered at locations throughout the Great Lakes and is of major concern not only environmentally but economically. It has already colonized numerous industrial and domestic water intakes in sufficient numbers to entirely block water flow and is also an intermediate host to parasites which eventually invade fish. 

Whyte, J.J., Van den Heuvel, M.R.M., and Clemons, J.H.M. et al. (1998). Mammalian and teleost cell line bioassays and chemically derived 2,3,7,8-TCDD equivalent concentrations in lake trout from Lake Superior and Lake Ontario, North America. Environmental Toxicology and Chemistry 17, 2214-2226. 

Rolfhus KR, Sakamoto HE, Cleckner LB, Stoor RW, Babiarz CL, Back RC, Manolopoulos H, Hurley JP. 2003. The distribution of mercury in Lake Superior. Environ Sci Technol 37 865-872. 

Barret, J.J., Faraick, W. and Jarvis, I. (1988) Rare-earth element geochemistry of some Archean iron formations north of Lake Superior, Ontario. Can. J. Earth Sci., 25, 570-586. 

By far the most important ores of iron come from Precambrian banded iron formations (BIF), which are essentially chemical sediments of alternating siliceous and iron-rich bands. The most notable occurrences are those at Hamersley in Australia, Lake Superior in USA and Canada, Transvaal in South Africa, and Bihar and Karnataka in India. The important manganese deposits of the world are associated with sedimentary deposits the manganese nodules on the ocean floor are also chemically precipitated from solutions. Phosphorites, the main source of phosphates, are special types of sedimentary deposits formed under marine conditions. Bedded iron sulfide deposits are formed by sulfate reducing bacteria in sedimentary environments. Similarly uranium-vanadium in sandstone-type uranium deposits and stratiform lead and zinc concentrations associated with carbonate rocks owe their origin to syngenetic chemical precipitation. 

Baker, J.E., Eisenreich, S J. (1990) Concentrations and fluxes of polycyclic aromatic hydrocarbons and polychlorinated biphenyls across the air-water interface of Lake Superior. Environ. Sci. Technol. 24, 342-352. 

Bloater, Coregonus hoyi liver Lake Superior vs. Lake 2.4 FW vs. 7.4 FW 1... 

Lake Superior, Siskiwit Lake, Isle Royale, 1983, whole ... 

Frank, R., R.L. Thomas, H.E. Braun, J. Rasper, and R. Dawson. 1980. Organochlorine insecticides and PCB in the surficial sediments of Lake Superior (1973). Jour. Great Lakes Res. 6 113-120. 

Swackhamer, D.L. and R.A. Hites. 1988. Occurrence and bioaccumulation of organochlorine compounds in fishes from Siskiwit Lake, Isle Royale, Lake Superior. Environ. Sci. Technol. 22 543-548. 

A. T. Lincoln to C. R. Van Hise, 19 October 1899, U. S. G. S. Lake Superior Division Official Correspondence, Box 6, State Historical Society of Wisconsin. 

The primary method for the disposal of liquid pesticide wastes in California in the past has involved soil evaporation pits, ditches, and ponds (Winterlin et al. 1989). A core soil sample taken from one such pit in northern California contained 44 mg/kg disulfoton at a depth of 90 cm (Winterlin et al. 1989). Disulfoton was detected in six of seven bottom soil samples from tail water pits used to collect irrigation runoff in Haskell County, Kansas, in 1974. The maximum and mean concentrations of disulfoton in these samples were 32.7 and 13.42 pg/kg respectively (Kadoum and Mock 1978). At a detection limit of 0.01 mg/kg, disulfoton was not detected in sediment samples collected from Lakes Superior and Huron, including Georgian Bay, in 1974 (Glooschenko et al. 1976). 

National Science Foundation (NSF), and the Chemical Oceanography program invests substantial resources in that area. The upper water column in the center of Lake Superior might be a good place to collect water for preparation of a freshwater trace metal reference material. 

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