Biochemistry, Biophysics, and Structural Biology Commons^™

Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman

Publications (WR)

Algal bioassay tests were conducted with Selenastrum capricornutum and natural algae on inner Las Vegas Bay, Lake Mead, Nevada, from December 1992 through September 1993, to identify any nutrient limitation in an area of the reservoir that has experienced problems associated with severe nutrient enrichment. Three areas were sampled based on a gradient of water quality conditions that existed in Las Vegas Bay (LVB). Disodium ethylenedinitrilotetraacetate (EDTA) significantly stimulated algal growth compared to non-EDTA treatment. Algal bioassays indicated that phosphorus (P) was the primary limiting nutrient at all stations for most of the test dates. Chl a response with EDTA …

Limnological Monitoring Data For Lake Mead During 1987: Technical Report No. 20, Larry J. Paulson

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1987. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.

Water Quality Trends In The Las Vegas Wash Wetlands, F. A. Morris, L. J. Paulson

Publications (WR)

The Las Vegas Wash is a wetlands ecosystem that acts to buffer the effects of wastewater discharges on the receiving waters of Lake Mead. The wash is the terminus for the 4,144 km2 Las Vegas Valley drainage basin, emptying into Las Vegas Bay of Lake Mead (Colorado River). It is in the northern Mojave desert, which receives an average of only 10 cm of rainfall annually. The Las Vegas Wash is technically an artificial wetland supported almost entirely by the perennial flows from sewage treatment plants. These flows contribute an average of 3-7 t of nutrients (nitrogen and phosphorus) and …

Nutrient Interactions Among Reservoirs On The Colorado River, Larry J. Paulson, John R. Baker

Publications (WR)

Interactions among physical, chemical and biological processes in reservoirs can significantly alter the characteristics of the discharge (Neel 1963, Wright 1967, Hannan 1979) that, in turn, can influence the ecology of the river downstream .(Ward and Stanford 1979). Investigations of the Colorado River, system reveal that reservoir-induced changes in the river can also affect downstream reservoirs. The formation of Lake Powell, in 1963 was accompanied by reductions in suspended sediment and nutrient loading and changes in the seasonal temperature and discharge cycles of the Colorado River. In this paper, we evaluate how these changes have influenced the nutrient and trophic …

Potential Use Of Hydroelectric Facilities For Manipulating The Fertility Of Lake Mead, Larry J. Paulson, John R. Baker, James E. Deacon

Publications (WR)

Analysis of historical nutrient data for Lake Mead indicates that the fertility of the reservoir has decreased which may be the cause for a corresponding decline in the largemouth bass population. However, it appears that fertility can be manipulated by altering the operation of the dam. The depletion of nutrients in the euphotic zone by phytoplankton and subsequent accumulation in the hypolimnion during summer and fall provide a natural nutrient gradient from which water of varying fertility can be drawn for discharge. This combined with alterations in the depth or seasonal pattern of discharge can possibly be used to enhance …

Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki

Publications (WR)

The ¹⁴C light and dark bottle technique for measurement of primary production was utilized as a means of assessing the amount of inorganic carbon being converted Into organic form by the photosynthesis of phytoplankton populations In the Boulder Basin of Lake Mead.

Spatial and time series changes of productivity levels observed at eight sampling locations within Boulder Basin Indicate that the Influence of treated municipal arts' industrial effluent flowing into Les Vegas Bay is contributing high levels of available nutrients at Las Vegas Wash Inlet to cause productivity to approximate those levels associated with polluted waters.

Productivity levels at …

Phytoplankton Successions And Lake Dynamics In Las Vegas Bay, Lake Mead, Nevada, Ervon R. Koening, Richard W. Tew, James E. Deacon

Publications (WR)

Phytoplankton successions, applications of the general growth equation, and physical measurements have been employed to investigate events occurring at the interface between industrial and sewage effluent contained in Las Vegas Wash and the waters of Lake Mead, Nevada. The data indicate that the entering waters tend to form a density current interrupted at intervals by dynamic effects generated in the lake. The dynamic relationships described here for the spring months suggest that a much more thorough understanding of physical, chemical and biological interactions is necessary to permit solution of the numerous problems of Las Vegas Bay discussed or alluded to …

A Mathmatical Model Of Primary Productivity And Limnological Patterns In Lake Mead, Lorne G. Everett

Publications (WR)

The temporal and spatial changes in chemical and biological properties of Lake Mead have been investigated, thereby indicating the sources of water pollution and the time of highest pollution potential. Planktonic organisms have been shown to indicate the presence of water problems. Macro- and micro-nutrient analyses have shown that primary productivity is not inhibited by limiting concentrations. A mathematical model has been developed, tested with one set of independent data, and shown worthy of management utility. Although the model works very well for the Lake Mead area, the physical reality of the Multiple Linear Regression equation should be tested on …

Report On Water Pollution Problems In Las Vegas Wash And Las Vegas Bay, Environmental Protection Agency

Publications (WR)

This report was prepared by the Federal Water- Quality Administration, Pacific Southwest Region, now the Environmental Protection Agency (EPA), Region IX, at the request of the State of Nevada, Department of Health, Welfare, and rehabilitation. In a letter, dated December 5, 1969, this agency asked for technical assistance, as authorized by the Federal Water Pollution Control Act, in developing discharge standards appropriate for Las Vegas Bay, Lake Mead, and the Lower Colorado River. The subsequent study was performed by EPA from January through August, 1970. The establishment of Nevada State Water Quality Standards for these waters will enable responsible officials …

A Conceptual Draft Of A Dynamic Hydro-Biological Model For Lake Mead, L. G. Everett, Bureau Of Reclamation

Publications (WR)

Food and energy transformation in an aquatic system must be understood in order to develop a simulation approach. This report provides a comprehensive study of an aquatic ecosystem. The objectives of this report are to show:

(1) the biological relationships in an aquatic system

(2) the role of nutrients in the biological cycle

(3) the role of abiotic factors in a limnetic environment

(4) the status of the art of "Eutrophication modeling".