Lakes and Reservoirs

Lakes and reservoirs are considered as standing waters and vary from gravel pits, ponds and canals to big natural lakes. In lakes (either natural or man made), water levels do not fluctuate much. Reservoirs are man-made open water storage facilities mostly serving as public utility water supply sources. Reservoirs are also used to store water for irrigation along with river corridors (http //www.euwfd.com/html/ lakes and reservoirs.html). The quality of water in lakes and reservoirs depends partly on the amount being drained in and partly on the speed at which the water moves in (http //www.unep.or.jP/ietc/publications/short series/lakereservoirs-l/5. 

Often a number of physical, chemical, and biological processes have to be considered as they may markedly affect water quality and its spatial variations. Sources of heterogeneity within a body of water that need careful consideration in selecting sampling sites are as follows  

Any of these factors acting alone or in combination may produce both lateral and vertical heterogeneity of water quality. 

Some important topics relevant to the choice of sites for sampling are noted (e.g.. Refs. [3,18]). It must be kept in mind that shallow and/or relatively isolated embayments of lakes and reservoirs may show marked differences in quality from the main body of water. 

Thermal stratification may retard the mixing of streams entering lakes or reservoirs. This important source of materials derived from the surrounding land consequently has to be sampled with due consideration of its spatial variability. 

The choice of the correct sampling point can depend on the depth of a lake [19]. These authors have compared different water sampling techniques in a series of lakes. 

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The stocking of ponds, lakes, and reservoirs to increase the production of desirable fishes that depend on natural productivity for their food supply and are ultimately captured by recreational fishermen or for subsistence is another example of extensive aquaculture. Some would consider such practices as lying outside of the realm of aquaculture, but since the practice involves human intervention and often employs fishes produced in hatcheries, recreational or subsistence level stocking is associated with, if not a part of aquaculture. Similarly, stocking new ponds or water bodies which have been drained or poisoned to eliminate undesirable species prior to restocking, can lead to increased production of desirable species. 

This is the principal linkage between cyanobacterial blooms and eutrophication. Avoidance of cyanobacterial production does not necessarily depend upon eliminating all phosphorus inputs, but upon ensuring that optimum physical and chemical conditions for these organisms do not coincide. It is easy to understand why the biggest blooms in the UK have been in fertile lakes and reservoirs after prolonged spells of warm, dry weather in summer. 

A. W. Fast, in Destratification of Lakes and Reservoirs to Improve Water Quality, ed. F. L. Burns and I.J. Fowling, Australian Water Resources Council, Canberra, 1981, p. 515. 

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). 

Tundisi JG (1983) A review of basic ecological processes interacting with production and stan-ding-stock of phytoplankton in lakes and reservoirs in Brazil. Hydrobiologia 100 223-243... 

Niimberg GK (2002) Quantification of oxygen depletion in lakes and reservoirs with the hypoxic factor. Lake Reserv Manage 18 299-306... 

Example of a Prey-Fish Indicator Yellow Perch Analyses of total mercnry in whole bodies or axial muscle tissue of age-1 yellow perch have provided a useful measure of MeHg concentrations in food webs of many North American lakes. This widely distributed species inhabits lakes and reservoirs across mnch of the north-central, northeastern, and eastern United States and across the central and eastern provinces of Canada (Scott and Crossman 1973 Becker 1983). An ecologically similar congeneric species, the Eurasian perch Perea fluvi-atilis), is distribnted across much of Europe and northern Asia (Thorpe 1977). 

Jackson, T.A. 1991. Biological and environmental control of mercury accumulation by fish in lakes and reservoirs of northern Manitoba, Canada. Canad. Jour. Fish. Aquat. Sci. 48 2449-2470. 

Benoit, J. M., Fitzgerald, W. F. Damman, A. W. H. 1998. The biogeochemistry of an ombrotrophic bog Evaluation of use as an archive of atmospheric mercury deposition. Environmental Research, 78, 118-133. Engstrom, D.R. Swain, E.B. 1997. Recent declines in atmospheric mercury deposition in the upper Midwest. Environmental Science and Technology, 31, 960-967. Engstrom, D.R., Swain, E.B., Henning, T.A., Brigham, M.E. Brezonik, P.L. 1994. Atmospheric Mercury Deposition to Lakes and Watersheds - a Quantitative Reconstruction from Multiple Sediment Cores. In Environmental Chemistry of Lakes and Reservoirs. 33-66. 

Fig. 22 Monthly variations in total water storage volumes in Switzerland from 1940 to 1981. Water storage volumes include medium-term changes in soil moisture, groundwater, snowpack, lakes, and reservoirs. Long-term changes in groundwater and glaciers are not taken into account [71]. Minimum and maximum years are indicated...

Sthapit KM (2005) Sedimentation of lakes and reservoirs with special reference to the Kulekani Reservoir. In Schreier H, Shah PB, Brown S (eds) Challenges in mountain resource management in Nepal. Processes, trends and dynamics in Middle Mountain Watersheds. ICIMOD Publ, Kathmandu, pp 5-12... 

Under natural conditions, Ri may be reduced by wind, so that spread monolayers of hexadecanol or similar materials may significantly retard evaporation. In the last few years they have found commercial application in reducing evaporation from lakes and reservoirs in hot, arid regions where the amount of water lost by evaporation may be so great as to exceed the amount usefully used. Another application is to reduce the evaporation from heated swimming-pools here it is important to save the latent heat of evaporation rather than the water. 

L. A. Baker (ed.), Environmental Chemistry of Lakes and Reservoirs, Advances in Chemistry Ser. 237. American Chemical Society, Washington, D.C., 1993. 

One area in which monolayers have been successfully employed is the retardation of evaporation. Particularly in arid regions of the world, evaporation of water from lakes and reservoirs constitutes an enormous loss of a vital resource. Under some conditions the water level of such bodies may change as much as 1 ft per month due to evaporation. The usual unit for water reserves is the acre-foot, a volume of water covering an acre of surface to the depth of 1 ft. It equals about 1/3 million gallons for each acre of water surface. Considerable research has been conducted both in the laboratory and in the field on the effectiveness of insoluble monolayers in reducing evaporation. An American Chemical Society Symposium in 1960 dealt exclusively with this topic the proceedings of that symposium are given by LaMer (1962). 

Moore, J. N. (1994). Contaminant mobilization resulting from redox pumping in a metal-contaminated river-reservoir system. In Environmental Chemistry of Lakes and Reservoirs, ed. L. A. Baker, pp. 451-71. Washington, D.C. American Chemical Society. Moore, J. N., Ficklin, W. H. Johns, C. (1988). Partitioning of arsenic and metals in reducing sulfidic sediments. Environmental Science and Technology, 22, 432-7. Morrison, G. M., Batley, G. E. Florence, T. M. (1989). Metal speciation and toxicity. Chemistry in Britain, 8, 791-5. 

Environmental chemistry of lakes and reservoirs / Lawrence A. Baker, editor, p. cm.—(Advances in chemistry series, 0065-2393 237)... 

Engstrom, D. R. In Environmental Chemistry of Lakes and Reservoirs Baker, L. A., Ed. Advances in Chemistry 237 American Chemical Society Washington, DC, 1994 Chapter 2. 

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