Ecology and Evolutionary Biology Commons^™

Benthic Diatom Community Dynamics In The Colorado River: Interactive Effects Of Periodic Dessication And Current Regime, Christopher Gerard Peterson

Publications (WR)

The response to periodic desiccation of periphyton communities developed in eddy environments or in areas exposed to variable, direct current was examined. Algal communities were incubated on clay tiles for between 2 and 12 weeks in the Colorado River, directly below Hoover Dam from October, 1983 - January, 1984. Mean daily discharge from the dam decreased over this period. To assess the influence of these discharge changes on community dynamics, samples collected over the first 12 weeks of the investigation were compared to samples of the same age collected over the final 8 weeks.

The small diatom taxon Achnahthes spp …

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

Publications (WR)

Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures.

Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982.

A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …

The Voluntary Water Quality Monitoring Program : 1982 Project Report, Barbara Welch, Judy Potvin, Mary Ellen Dennis

Maine Collection

The Voluntary Water Quality Monitoring Program : 1982 Project Report

by Barbara Welch, Judy Potvin & Mary Ellen Dennis

Division of Environmental Evaluation and Lake Studies, Maine Department of Environmental Protection, Augusta, Maine 1982.

Contents: Understanding Maine's Lakes and Ponds / Acknowledgement / Temperature / Dissolved Oxygen / Other Measures of Lake Water Quality / Nutrients / Algae and Chlorophyll a / Transparency / Morphometry / Sampling / Protection / Classification / Answers to Most Frequently Asked Questions / Glossary of Terms / Appendix A : Maximum, Minimum, and Mean Values / Appendix B : Phosphate Content of Common Cleansers …

A Limnological Study Of 43 Selected Maine Lakes, Derrill J. Cowing, Matthew Scott

Maine Collection

A Limnological Study of 43 Selected Maine Lakes

by Derrill J. Cowing and Matthew Scott

U.S. Geological Survey : Water-Resources Investigations 80-69

Prepared in cooperation with the Maine Department of Environmental Protection

U.S. Geological Survey, 26 Ganneston Drive, August, Maine 04330

Interactions In Lambdoid Bacteriophage Populations, Bruce Edward Mitchell

Masters Theses

The lambdoid bacteriophages are ideal subjects for the study of populational interactions at the molecular level because they do not mutually exclude one another in mixed infection of the same host cell. Previous work done in this laboratory using the lambdoid phage pairs λ-434 hy mi and λ-∅80 have demonstrated a density-dependent reduction in progeny yield per infected cell (burst size) as a function of increasing multiplicity of infection (m.o.i.). The λ cI gene which codes for the repress or molecule has been demonstrated to be the cause of the interaction in the λ-434 hy mi phage pair. …

A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman

Publications (WR)

1. The waters of Las Vegas Bay, a heavily utilized recreational resource, receive discharges from a variety of municipal and industrial waste sources. The U.S. Environmental Protection Agency has determined, on the basis of numerous studies, that the present water quality violates state and federal standards and constitutes a public nuisance. Consultants have advised the Sewage and Wastewater Advisory Committee that rapid abatement of the alleged pollution conditions can be achieved by an advanced wastewater treatment (AWT) plant.

2. The major problems in Las Vegas Bay are an objectionable water color, excessive turbidity, noxious odors, and oxygen depletion in certain …

Report On Wastewater Disposal To Board Of County Commissioners, Clark County Nevada, Clair N. Sawyer

Publications (WR)

This report is concerned with the management of waste-waters and subsurface drainage from the City of Las Vegas and its environs and the BMI complex, all in Clark County, Nevada. The prime objective is to recommend a plan of action which will utilize the natural resources of the area in the least costly manner and still protect Lake Mead for recreational purposes and use as a public water supply, At this writing, conditions in the upper Las Vegas arm of Boulder Basin are quite unsatisfactory for some recreational purposes due to the extensive blooms of algae which develop. Experience at …

Karyotype Of Geomys Pinetis (Mammalia: Geomyidae), With A Discussion Of The Chromosomal Relationships Within The Genus, S. L. Williams, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Summary. Four of the five subspecies of Geomys pinetis were karyotyped. All specimens examined had a diploid number of 42 and a fundamental number of 80. This karyotype was compared with the described karyotypes of other species of Geomys and was considered to be derived from an ancestoral form having a karyotype of about 70 acrocentric elements.

Phomopsis : The Causal Fungus Of Lupinosis, P Mcr Wood, A. G. P. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

It is now well known that lupinosis of sheep and cattle follows ingestion of lupin stubble colonised by the fungus Phomopsis rossiana. The fungus infects green lupins but persists on the stubble and under certain conditions apparently produces a toxin which causes the disease.

As Phomopsis is now widespread on lupins in Western Australia its ecology has been studied in detail as a basis for possible control measures.

This article outlines what is known so far of the disease and its control.

A Statistical Approach To The Study Of The Ecosystems Of Seven Ponds In East-Central Illinois, Gregory Lee Orr

Masters Theses

Gross primary productivity, heterotrophic bacterial numbers, and net phytoplankton densities of seven ponds in Coles County, Illinois, were studied in relation to physical, chemical, and biological habitat variables (light intensity and duration, turbidity, water temperature, pH, dissolved oxygen, sulfur, nitrogen, phosphorus, production, bacteria, and phytoplankton). Ten observations were made for each pond (except where otherwise noted) from 17 June through 25 August 1974. Stepwise multiple linear regression analyses of the data were used in order to determine those environmental factors which were important in predicting (i.e., significantly correlated with) bacterial and phytoplankton densities, and production. A multiple linear regression equation …

Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett

Publications (WR)

Phytoplankton samples were collected in Lake Mend 6 times from September 1910 to June 1971 for 8 stations at depths of 0. 3, 5, 10, 20, and 30 m. These samples were processed through a Millipore filter apparatus and 79 planktonic algae were identified. Algal divisions represented were Bacillariophyta, 42 species; Chlorophyta, 18 ; Cyanophyta, 9; Chrysophyta, 3; Cryptophyta, 3; Pyrrophyta, 2; and Euglenophyta, 2. Blue-green algae were dominant in late summer and fall; green algae, diatoms, and, cryptomonads in winter; and green algae in spring. The early summer flora was best represented by the Chlorophyta, Cryptophyta, and Chrysophyta. Palmer's …

A Diurnal Zooplankton Migration Study In Lake Mead, Robert D. Staker

Publications (WR)

The diurnal vertical movement of zooplankton was first recorded in freshwater lakes by Weismann (1877) in Lake Constance (Bodensee), although Cuvier was credited with observing the migration of Daphniae in 1817 (Gushing, 1955). The migration is best observed in deep oligotrophic lakes and migrations of 50 m per day are described (Worthington, 1931). In addition, two species of chaetognaths are reported to migrate 400 m a day in marine waters off of Lisbon (Waterman and Berry, 1967) while Birge (1895) found little evidence of the phenomenon at all in Lake Mendota, Wisconsin.

Most zooplankton that migrate rise at night and …

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 …

Spatial Distribution & Temporal Occurrence Of Rotifers In The Main Pool & Tailwater Of Barren Lake, Kentucky, David Abel

Biology Graduate Theses

A study of the spatial distribution and temporal occurrence and diversity of rotifers in relation to certain chemicophysical parameters was conducted in Barren Lake, Kentucky, a flood control lake, from January, 1970, through January, 1970. Paired samples were collected from six depths in the main pool area of the reservoir and from an automatic plankton sampler installed in the tailwater area where, from April through September, the effluent was derived from the upper 3 m of the pool . Diel studies were conducted in April, July, 1970, and January, 1971.

Barren Lake began to stratify in late April, was completely …

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation

Publications (WR)

Progressive increases in concentration of dissolved solids in the Colorado River water from Lake Powell to Imperial Dam seem to alter plankton dynamics and biological productivity of the river. Also, changes in biological productivity and micronutrients concentrations occur within the same reservoir. Development of a digital simulation model to predict micronutrients concentrations and biological productivity is necessary for diagnosing changes in plankton population and effluent-carrying capacity of the system.

The objectives of the study are: (1) to determine trace metal balance at different locations in Lake Mead, (2) to measure biological productivity and conduct plankton population counts at each sampling …

Enteric Bacteria In Aquatic Turtles, David Alger Gapp

Dissertations, Theses, and Masters Projects

No abstract provided.

Biological Studies Of Selected Reaches And Tributaries Of The Colorado River, Nelson Thomas, Federal Water Pollution Control Administration

Publications (WR)

This report fulfills the request of the Colorado River Basin Project, Denver, Colorado, to determine the effects of municipal and industrial wastes on the aquatic life in selected waters of the Colorado River Basin. These studies were conducted with the assistance of personnel from the Colorado River Basin Project.

Ecological Study Of The Effects Of Strip Mining On The Microbiology Of Streams, Ralph H. Weaver, Harry D. Nash

KWRRI Research Reports

The microflora of Cane Branch of Beaver Creek in McCreary County, Kentucky, which drains an area that was strip-mined between 1955 and 1959, was studied and compared with that of Helton Branch which drains a comparable area where there has been no mining. Differences include: the establishment of Ferrcbacillus ferrooxidans, for which procedures were developed for direct colony isolation from the stream; fewer saprophytic bacteria; more numerous and more diversified filamentous and unicellular fungi; and characteristic differences in algal flora. Representatives of 42 genera of filamentous fungi were identified. Of these, 21 were isolated only from Cane Branch. Representatives of …

Studies On The Planktonic Protozoa And Other Microbiota Of A Eutrophic Lake, Neil Howard Chance

Masters Theses

No abstract provided.

Preliminary Report: Monolayer Behavior Studies, 1959, Bureau Of Reclamation

Publications (WR)

During the fall of 1959, monolayer behavior studies were made on two lakes in the southwest; Boulder Basin of Lake Mead, Nevada, and Lake Sahuaro near Phoenix, Arizona.

These studies were made to evaluate the effect of geographical and climatological conditions on movement and behavior of monolayers. The Lake Sahuaro tests also were used to provide data for design and development of improved methods of application and maintenance of a film on this lake in anticipation of full scale, evaporation-reduction tests to be performed there during the summer of I960.

The Lake Mead studies produced the following general points of …

Microorganisms And Soil Structure, T. M. Mccalla

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Laboratory tests were made to determine the effectiveness of different compounds and microbial groups in increasing the stability of Peorian loess lumps against the action of falling water drops. The influence of these on percolation tests in the laboratory was also determined.

Many organic substances-dextrose, sucrose, starch, peptone, cullulose, and gum arabic-did not themselves contribute directly to soil-structure stability, though these substances do furnish energy material for soil microorganisms, which can convert them readily into either microbial tissue or decomposition products that increase soil-structure stability. Lignin, proteins, oils, fats, waxes, resin, and paraffin increased the stability of lumps of …

Studies On The Microcrustacea Of Three Montane Lakes In Glacier National Park, Montana, Robert O. Megard

Biology ETDs

Grinnell Lake, Lake Josephine, and Swiftcurrent Lake, at an elevation of approximately 5,000 feet in northwestern Montana, are comparable with lakes in the montane zone defined by Pennak for lakes at elevations between 8,200 feet and 10,500 feet in the Rocky Mountains of northern Colorado. Five species of Copepoda, six Cladocera, and four Ostracoda were collected in the lakes studied. The population of microcrustacea in these lakes was most dense in or slightly above the masses of rooted aquatic vegetation growing to a height of six to 10 inches above the bottom wherever the water was between three feet and …