Geology topics
L. J. Britton
Publications and source records attributed to L. J. Britton.
Methods for collection and analysis of aquatic biological and microbiological samples
Chapter A4, methods for collection and analyses of aquatic biological and microbiological samples, contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. Part 1 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity and bioassay. Each method is summarized, and the applications, interferences, apparatus, reagents, analyses, calculations, reporting of results, precisions, and references are given. Part 2 consists of a glossary. Part 3 is a list of taxonomic references. (USGS)
Water-quality assessment of Arvada Reservoir, Denver metropolitan area, Colorado
Water quality data were collected from Arvada Reservoir, Colorado, and from its major inflows, Ralston Creek and Croke Canal, to assess the water quality of the reservoir, to evaluate the effect of water from various sources on the reservoir, and to estimate the trophic state of the reservoir. Data were collected at five sites in Arvada Reservoir, one site in Ralston Creek, and two sites in Croke Canal. The study began in June 1983 (just before filling in May 1984) and continued through September 1985. The reservoir was thermally stratified on most sampling dates from April through September. Dissolved-oxygen concentrations ranged from 0 to 12.0 milligrams per liter, and the reservoir was anaerobic below the 10-meter depth during most of the summer. Secchi-disk-depth measurements ranged from 0.9 to 5.5 meters and generally increased during the study period, possibly because of decreases in nonalgal turbidity after the reservoir was filled. Water from the reservoir generally is of suitable quality for a raw-water-supply source and for maintenance of aquatic life. Total-nitrogen and total-phosphorus concentrations were small, and both were growth-limiting factors in the reservoir. The phytoplankton community was diverse, and the most dominant taxa were diatoms. Phytoplankton densities ranged from 1,400 to 29,000 cells per millimeter, and chlorophyll alpha concentrations ranged from 0.0 to 20.4 micrograms per liter. (USGS)
Water-quality data for Arvada Reservoir, Denver metropolitan area, Colorado
Physical, chemical, and biological water quality data were collected and compiled for five sites in Arvada Reservoir, one site in Ralston Creek, and two sites in Croke Canal, in the Denver metropolitan area, Colorado. The purpose of the data collection was to determine the water quality of Arvada Reservoir, evaluate the effect of source waters on the reservoir , and determine the trophic state of the reservoir. Data collected include reservoir profile measurements with depth and inflow measurements of water temperature, specific conductance, dissolved oxygen, and pH. Secchi disk depth measurements also are reported. In addition, water samples were analyzed periodically for concentrations of major chemical constituents, nutrients, trace elements, and selected radiochemicals; for densities and relative abundance of phytoplankton and zooplankton; and for concentrations of chlorophyll alpha. Results of algal growth potential determinations are included. This report describes sampling site locations and methods of data collection and analyses and presents qualitative and quantitative results of water quality data collected during the study. Sampling began during June 1983 and continued through September 1985. (USGS)
Data compilation of benthic invertebrates from tributary streams in Yampa and North Platte River Basins, northwestern Colorado
Benthic invertebrates were collected from Trout Creek, Fish Creek, and the Williams Fork (tributaries of the Yampa River in Routt and Moffat Counties), and Little Grizzly and Grizzly Creeks (tributaries of the North Platte River in Jackson County). Stream-sampling sites were upstream and downstream from potential, existing, or historical coal-mining areas. Field water-quality measurements of water temperature, specific conductance, pH, and dissolved oxygen were also made to aid in assessing stream water-quality conditions. The purpose of the study was to describe and quantify the benthic invertebrate communities in selected streams in coal-mining areas. Sampling was conducted on a near bimonthly basis throughout the growing season, beginning in April and May 1980, and continuing through September 1981. This report describes the methods of data collection and presents qualitative and quantitative results of benthic invertebrates and associated water-quality data. (USGS)
Reconnaissance of benthic invertebrates from tributary streams of the Yampa and North Platte River basins, northwestern Colorado
Benthic invertebrates were collected from tributaries of the Yampa River in Routt and Moffat Counties, and tributaries of the North Platte River in Jackson County. Field water-quality measurements of water temperature, specific conductance, pH, dissolved oxygen, and bed material size were also made to aid in assessing stream water-quality conditions. The purpose of the study was to describe and quantify the benthic invertebrate communities in selected streams in coal mining areas. Stream sampling sites were located upstream and downstream from potential, existing, or historical coal mining areas. Sampling was conducted on a near bimonthly basis throughout the growing season, beginning in April and May 1980, and continuing through September 1981. The density of benthic invertebrates generally increased downstream in all streams sampled. Most of the variation in densities and taxa among the stream sites was associated with sampling date differences. There were also some strong correlations of benthic invertebrate densities with measured water-quality constituents and properties. However, a larger sample size (greater frequency of sampling) may influence this relation. (USGS)
An introduction to the processes, problems, and management of urban lakes
Lakes are bodies of water formed in depressions on the earth's surface, and as such, act as depositories for a variety of chemical and biological materials. The study of lakes has become increasingly prevalent in recent years. Lakes are a valuable resource, and their multiple uses have made them susceptible to water-quality problems such as algal blooms, sediment deposition and fish kills. These problems are products of the eutrophication process (enrichment, aging and extinction of lakes), which is often accelerated by man. Therefore, it becomes important to understand the properties and processes of lakes which govern lake enrichment, and the measures available to control enrichment. Lakes are described in terms of their physical (light penetration, temperature, sediment, and morphology), chemical (chemical constituents, plant nutrients:, and dissolved gases) and biological (plankton, benthos, and nekton) properties. These properties are all interre]ated, and are important variables to measure to evaluate water quality. In addition, lake processes, such as photosynthesis, respiration, eutrophication, and biogeochemical cycling, are important factors in determining the sources and extent of enrichment, and managing a lake for maximum benefit. Meeting demands for water of high quality requires a general knowledge of lake properties and processes, coupled with lake-basin planning, watershed and lake management, and water-quality control. There are many lake-management and control practices, but the best tools for quality control are preventive measures. Once extensive enrichment has occurred, there are few management or control options available. As lake studies become more common, sampling techniques for data collection need increased accuracy and consistency, in order to make meaningful comparisons between different lakes. Therefore, the report discusses the main factors involved in conducting lake studies. These factors include the types and frequency of measurements useful in lake reconnaissance studies and a review of literature on sampling equipment and techniques. A glossary of selected terms begins the report, which is intended for guideline use by urban planners and managers.