Terrestrial and Aquatic Ecology Commons^™

Winter Survival Strategies Of Benthic Invertebrates In Temporary Habitats In A Northern Minnesota Lake, Cal Oldenburg

Journal of Earth and Life Science

During the winter months in the northern hemisphere, above 40 degrees latitude, a freezing event occurs that can last several months. Some lakes may have large portions of the shallow littoral zone frozen completely solid down into the sediments. Invertebrates affected by these events have developed survival strategies to cope with the harsh environment. The two main strategies for invertebrates in these areas are to either migrate to a different area and recolonize the original area when it becomes available again, or to burrow into the sediments and withstand the freezing. A 1- month study took place on Lake Bemidji …

Comparison Of The Effects Of Toxic Cyanobacteria On The Reproductive Success Of Eurytemora Affinis Populations In The Baltic Sea And Green Bay, Wisconsin, Amanda Dwyer

Lawrence University Honors Projects

The Northern Baltic Sea, off the southern coast of Finland, and Green Bay, off Lake Michigan in Wisconsin, both experience large toxic cyanobacteria blooms, especially during the summer and early fall months. Nodularia spumigena is the toxic algae in the Baltic Sea and produces the toxin Nodularin. Nodularin is a toxin that has branched from the toxin Microcystin, which is produced by Microcystis, the toxic algae forming blooms in Green Bay. While the toxin often acts as a defense mechanism to deter zooplankton from grazing, the calenoid copepod Eurytemora affinis, with populations in both the Baltic and Green Bay, …

White Bass Assessment In Regards To Changes In Water Level On Lake Traverse, Aaron Wilson

Journal of Earth and Life Science

Until recently the white bass Morone chrysops has been somewhat ignored by anglers, more so in Minnesota than other states; most likely due to their limited distribution throughout the state. However, with more anglers becoming aware of the sporting and culinary potentials of white bass, interests have risen. With this rise in angler interest, there should be a rise in white bass assessments. Knowing what factors may be influencing white bass population dynamics will allow fisheries professionals to better manage and protect white bass fisheries. White bass are often found in rivers and impoundments were dams are present and water …

Brown Trout Spawning Location And Relationship To Suitable Winter Habitat, Matthew L. Skoog

Journal of Earth and Life Science

Brown trout are a popular game fish throughout much of the world. Understanding habitat requirements is necessary for the successful management of brown trout. This study looks at the spawning habitat preferences and relationship of redd location to wintering habitat of brown trout in the Straight River, Minnesota. Brown trout in the Straight River were found to spawn in similar habitat to brown trout looked at in previous literature. All redds were located on gravel substrate. Seventy eight percent of redds were associated with some sort of cover. Water velocities at the redd sites. (mean=0.456 ms/cm), dissolved oxygen (mean=9.78 mg/L), …

Comparison Of A Length Size Limit Of Northern Pike Population On Two Lakes In North Central Minnesota, Ethan A. Puttonen

Journal of Earth and Life Science

Fisheries managers use length size limits on northern pike (Esox lucis) to improve the size structure in select lakes. The objective of this study was to compare two similar lakes, one with a length size limit and one without, to determine if a length size limit is improving the northern pike size structure. Blueberry Lake showed a higher abundance of larger fish than Stocking Lake. Of the fish caught, 25% in Blueberry Lake were over 600 mm (24 in), and were in the protected slot. Stocking Lake had a smaller portion of fish of this size with only …

Integrating Ecology And Economics For Restoration: Using Ecological Indicators In Valuation Of Ecosystem Services, Eric T. Schultz, Robert Johnston, Kathleen Segerson, Elena Y. Besedin

EEB Articles

Because it can uniquely furnish insights into nonuse values for ecosystem services, survey-based Stated Preference (SP) valuation is widely used to estimate the benefits of ecological restoration. SP surveys ask respondents to select among restoration options yielding different ecological outcomes. This review examines the representation of ecological outcomes in SP studies seeking to quantify values for restoration of aquatic ecosystems. To promote the validity of ecological indicators used in SP valuation, we identified four standards: indicators should be measurable, interpretable, applicable, and comprehensive. We reviewed recent SP studies estimating the value of aquatic ecosystem services to assess whether ecological indicators …

Hydrologic Connectivity And The Contribution Of Stream Headwaters To Ecological Integrity At Regional Scales, Mary C. Freeman, Catherine M. Pringle, C. Rhett Jackson

United States Geological Survey: Staff Publications

Cumulatively, headwater streams contribute to maintaining hydrologic connectivity and ecosystem integrity at regional scales. Hydrologic connectivity is the water-mediated transport of matter, energy and organisms within or between elements of the hydrologic cycle. Headwater streams compose over two-thirds of total stream length in a typical river drainage and directly connect the upland and riparian landscape to the rest of the stream ecosystem. Altering headwater streams, e.g., by channelization, diversion through pipes, impoundment and burial, modifies fluxes between uplands and downstream river segments and eliminates distinctive habitats. The large-scale ecological effects of altering headwaters are amplified by land uses that alter …

Interactions Among Environmental Drivers: Community Responses To Changing Nutrients And Dissolved Organic Carbon, Jennifer L. Klug, Kathryn L. Cottingham

Dartmouth Scholarship

Biological communities are frequently exposed to environmental changes that cause measurable responses in properties of the community (hereafter called environmental drivers). Predicting how communities respond to changing environmental drivers is a fundamental goal of ecology. Making predictions, however, can be very difficult, particularly when multiple environmental drivers change simultaneously and there are interactions among the drivers. We investigated the effects of the interaction between changes in nutrient loading and changes in colored dissolved organic matter (measured as dissolved organic carbon, DOC) on the dynamics of phytoplankton communities over a 7‐yr period. In 1991, Long Lake, a small seepage lake in …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume Ii Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Baseline Water Quality Data Inventory And Analysis: Lake Mead National Recreation Area, Volume I Of Ii, National Park Service

Publications (WR)

This document presents the results of surface-water-quality data retrievals for Lake Mead National Recreation Area (LAME) from five of the United States Environmental Protection Agency's (EPA) national databases: (1) Storage and Retrieval (STORET) database management system; (2) River Reach File (RF3); (3) Industrial Facilities Discharge (IFD); (4) Drinking Water Supplies (DRINKS); and (5) Flow Gages (GAGES). This document is one product resulting from a cooperative contractual endeavor between the National Park Service's Servicewide Inventory and Monitoring Program, the National Park Service's Water Resources Division (WRD), and Horizon Systems Corporation to retrieve, format, and analyze water quality data for all units …

Temporal And Spatial Variation In Pelagic Fish Abundance In Lake Mead Determined From Echograms, Gene R. Wilde, Larry J. Paulson

Publications (WR)

Echograms have been used extensively to locate and estimate the relative abundance of marine fish stocks (Cushing 1973). In freshwater, echograms have been used to describe vertical (Netsch et al. 1971; Eggers 1978; O'Brien et al. 1984; Matthews et al. 1985), spatial (O'Brien et al. 1984; Wanjala et al. 1986) and temporal (Baker and Paulson 1983) patterns in fish abundance. Although most uses of echograms have been qualitative, Mullan and Applegate (1969) and Matthews et al. (1985) obtained relative estimates of fish abundance by counting targets (fish) on echograms. However, neither Mullan and Applegate (1969) nor Matthews et al. (1985) …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines. Because …

Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel

Publications (WR)

Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and fiannehnouth sucker), the final preferendum is a less precise indicator of probable distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a …

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 …

The Role Of Nannoplankton In The Phytoplankton Dynamics Of Four Colorado River Reservoirs (Lakes Powell, Mead, Mohave, And Havasu), Jeffrey John Janik

Publications (WR)

Phytoplankton species composition and community size structure were studied in four warm-monomictic Colorado River reservoirs; lakes Powell, Mead, Mohave, and Havasu from March 1981 to February 1982. Sampling was done at approximately monthly intervals from several stations in each reservoir. The Utermohl technique was used to enumerate phytoplankton. The phytoplankton assemblage was divided into the following six size classes using microscopic techniques; netplankton (>64 um), and nannoplankton (>5, 5-11, 12-21, 22-44, and 45-64 um).

Total phytoplankton biomass and community size structure were different among these four reservoirs with considerable spatial and temporal variation present. Average reservoir-wide areal weighted …

The Ecology Of The Mottled Sculpin, Cottus Bairdii, In The Clearwater River, Beltrami County, Minnesota, Mark A. Hanson

Biology Graduate Theses

No abstract provided.

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 …

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.