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Articles 751 - 780 of 1200

Full-Text Articles in Fresh Water Studies

Bulletin 4279 - Streamlining - An Environmentally Sustainable Drainage Network For The Swan Coastal Plain (Peel-Harvey Catchment), Garry Heady, Neil Guise Aug 1994

Bulletin 4279 - Streamlining - An Environmentally Sustainable Drainage Network For The Swan Coastal Plain (Peel-Harvey Catchment), Garry Heady, Neil Guise

Bulletins 4000 -

Community Catchment Centre Pinjarra

A network of over 1400 kilometres of drains and modified natural waterways constructed by the Public Works Department criss-crosses the Peel-Harvey catchment. There are also over 3300 kilometres of minor drains and natural waterways in this same region.

The expansion of agriculture relied on this extensive drainage network, which was designed to ensure rapid drainage of the region. Unfortunately there was little regard to future environmental consequences.

Along with drainage water, these same drains now carry high loads of silt and nutrients. Many of the drains are also degraded and require expensive maintenance annually.


Miscellaneous Publication 10/94 - The Climate And Soils Of South-Western Australia In Relation To Vine Growing, J. S. Gladstones Mar 1994

Miscellaneous Publication 10/94 - The Climate And Soils Of South-Western Australia In Relation To Vine Growing, J. S. Gladstones

Viticulture research reports

The vine industry in Western Australia is at present located mainly in the Swan Valley, some 15 miles inland from Perth. It produces currants for export, wine grapes, and table grapes for both local and export markets, in approximately that order of importance.

Climatically, the Swan Valley is well suited to vine fruit production. With an annual rainfall of about 34 inches, it has a mild, wet, almost frost-free winter, and a warm, dry summer. Olmo (1956) concluded that the Swan was especially well suited to the production of currants, table grapes and sweet dessert wines. However, he considered that …


Study Of Existing Information Concerning Water Quality Within Lake Mead, Vicki Scharnhorst, Southern Nevada Water Authority Feb 1994

Study Of Existing Information Concerning Water Quality Within Lake Mead, Vicki Scharnhorst, Southern Nevada Water Authority

Publications (WR)

The purpose of Task 010A15M of the Southern Nevada Water Authority (SNWA) Treatment and Transmission Facility (TTF) contract is to conduct a study of existing information concerning water quality within Lake Mead and identify additional water quality studies that are needed to supplement existing data. The objective of this task is not to discuss treatability of the raw water source; this is addressed by Task 010A18M, "Define Water Treatment Requirements." In addition, a narrative on the effect of pending Safe Drinking Water Act amendments and a determination of treated water quality goals is included in Task 010A16M, "Review Safe Drinking …


Bulletin 4278 - How To Use Wide Furrow Sowing For Improved Crop Production On Water Repellent Sand, Paul Blackwell, Grant Morrow, Tony Webster Feb 1994

Bulletin 4278 - How To Use Wide Furrow Sowing For Improved Crop Production On Water Repellent Sand, Paul Blackwell, Grant Morrow, Tony Webster

Bulletins 4000 -

Wide furrow sowing is a method for successfully establishing crops of lupins or cereals on non-wetting sands, and improving crop establishment on non-repellent sands. The same principles can be used to assist establishment of fodder shrubs and long-term pasture (e.g. tagasaste and Rhodes grass).


Sport Fisheries Of The Belgrade Lakes, Maine Department Of Inland Fisheries & Wildlife Jan 1994

Sport Fisheries Of The Belgrade Lakes, Maine Department Of Inland Fisheries & Wildlife

Maine Collection

Sport Fisheries of the Belgrade Lake

Maine Department of Inland Fisheries & Wildlife, Augusta, Maine 1994.

Contents: Belgrade Lakes Chain, Some Vital Statistics / Some Features of the Seven Major Waters of the Belgrade Chain of Lakes / A Partial List of Fish Species That Occur in the Major Waters of the Belgrade Chain of Lakes / East Pond Oakland and Smithfield / Great Pond Oakland, Belgrade, and Rome / Long Pond Mt. Vernon, Rome, and Belgrade / Messalonskee Lake Oakland and Belgrade / North Pond Smithfield, Rome, and Mercer / Salmon Lake and McGrath Pond Belgrade and Oakland



A Trophic Gradient Analysis Of Lake Powell: The 1994 Utah State University Aquatic Ecology Laboratory Analyses, Wayne A. Wurtsbaugh, Megan Barker, Ron Brunson, David Fogle, Scott Hawxhurst, Chad Mellison, Lis Phillips, Felipe Queiroz, Daniel Zamecnik Jan 1994

A Trophic Gradient Analysis Of Lake Powell: The 1994 Utah State University Aquatic Ecology Laboratory Analyses, Wayne A. Wurtsbaugh, Megan Barker, Ron Brunson, David Fogle, Scott Hawxhurst, Chad Mellison, Lis Phillips, Felipe Queiroz, Daniel Zamecnik

Watershed Sciences Faculty Publications

From 9-11 April, 1994, the Aquatic Ecology Laboratory Class (FW462) of Utah State University sampled the upper reaches of Lake Powell to assess if a trophic gradient existed. We °ampled physical and chemical parameters (temperature, oxygen, conductivity, and total phosphorus), phytoplankton chlorophyll a, littoral and pelagic zooplankton biomass and composition, littoral and profundal benthic invertebrates, and fish abundance measured in the littoral zone (gill nets) and the pelagic zone (hydroacoustics). Data was collected along the upper 50 miles of the reservoir between Bullfrog and the Hite marina near the Colorado River inflow.

Our field trip was done just prior to …


Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher Jan 1994

Habitat Selection By Lacustrine Rainbow Trout Within Gradients Of Temperature, Oxygen, And Food Availability, Chris Luecke, D. Teuscher

Watershed Sciences Faculty Publications

Rainbow trout (Oncorhynchus mykiss [Walbaum]) in Castle Lake, California were concentrated at certain depths during day and evening hours. A fish bioenergetics simulation model based on vertical gradients of temperature, oxygen concentration, and food availability indicated that rainbow trout selected habitats that maximized growth rate. In 1 of the 2 years of study, a strong pattern of diel vertical migration of rainbow trout was evident and was associated with vertical migrations of daphnids in the lake. The simulation model correctly predicted the occurrence and magnitude of fish migration. During the day some trout resided at depths with little potential for …


Aquatic Macrophytes Of Two Small Northwest Arkansas Reservoirs, John J. Sullivan, Arthur V. Brown Jan 1994

Aquatic Macrophytes Of Two Small Northwest Arkansas Reservoirs, John J. Sullivan, Arthur V. Brown

Journal of the Arkansas Academy of Science

Lake Fayetteville and Lake Wedington are small reservoirs of about the same size and age that are located in northwestern Arkansas. We collected macrophytes from eleven transects around each reservoir in the autumn of 1993. Justicia (waterwillow), Typha (cat-tail), Scirpus (bulrush), Potamogeton (pondweed), and Zannichellia (horned pondweed) occur in both reservoirs. Justicia occurs most commonly in both reservoirs. The macrophytes of Lake Wedington are organized in a characteristic zonation pattern with bands from shore toward open water of emergent, floating-leaved, then submersed macrophytes. Macrophyte zonation was not as evident in Lake Fayetteville because of the low occurrence of floating leaved …


Population-Dynamics Of Juvenile Caribbean Spiny Lobster, Panulirus-Argus, In Florida Bay, Florida, David Forcucci, Mark J. Butler Iv, John H. Hunt Jan 1994

Population-Dynamics Of Juvenile Caribbean Spiny Lobster, Panulirus-Argus, In Florida Bay, Florida, David Forcucci, Mark J. Butler Iv, John H. Hunt

Biological Sciences Faculty Publications

Despite a wealth of information on the growth and population dynamics of sub-adult and adult Caribbean spiny lobsters (Panulirus argus), there is far less information about younger juveniles under natural conditions. Here we describe growth and population dynamics of juvenile spiny lobsters (12-68 mm carapace length, CL) that we have studied for 14 months (October 1988-December 1989) using mark-recapture techniques in a hardbottom community in Florida Bay, Florida. We also monitored the supply of postlarvae into the region in 1988 and 1989 using Witham-type surface collectors in an effort to link peak periods of settlement of postlarvae with subsequent cohorts …


Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation Jan 1994

Identification Of Tire Leachate Toxicants And A Risk Assessment Of Water Quality Effects Using Tire Reefs In Canals, S. M. Nelson, G. Mueller, D. C. Hemphill, U.S. Bureau Of Reclamation

Publications (WR)

Cover is an important component of aquatic habitat and fisheries management. Fisheries biologists often try to improve habitats through the addition of natural and artificial material to improve cover diversity and complexity. Habitat-improvement programs range from submerging used Christmas trees to more complex programs using sophisticated artificial habitat modules. Used automobile tires have been employed in the large scale construction of reefs and fish attractors in marine environments and to a lesser extent in freshwater and have been recognized as a durable, inexpensive and long-lasting material which benefits fishery communities.

Recent studies by the U.S. Bureau of Reclamation have quantified …


Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh Jan 1993

Snake River Sockeye Salmon Habitat And Limnological Research, David Teuscher, Doug Taki, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Historically, thousands of Snake River Sockeye salmon returned to the Sawtooth Valley to spawn. Evermann (1896) reported that the Sawtooth Valley Lakes were teeming with red fish. Bjornn (196~) estimated that 4,360 sockeye returned to Redfish Lake in 1955. These numbers no longer exist. In the 1980's, less than 50 Snake River sockeye salmon survived to spawn (Bowler 1990). Since 19-90, only 13 sockeye have returned. Because of recent declines, the Shoshone-Bannock Tribes (SBT) petitioned the National Marine Fisheries Service (NMFS-) to list Snake River sockeye as endangered. As a result, Snake River sockeye were listed and the Bonneville Power …


A Reproductive-Resting Stage In An Harpacticoid Copepod, And The Significance Of Genetically Based Differences Among Populations, D. J. Lonsdale, P. Weissman, Fred C. Dobbs Jan 1993

A Reproductive-Resting Stage In An Harpacticoid Copepod, And The Significance Of Genetically Based Differences Among Populations, D. J. Lonsdale, P. Weissman, Fred C. Dobbs

OES Faculty Publications

Dormancy is an important life-history strategy which allows copepods to increase their fitness by delaying growth and reproduction until harsh environmental conditions have ameliorated. For marine species, the primary strategies identified to date include the production of dormant eggs by shallow-water species, and copepodite overwintering in deep-water species. Herein, we describe a third strategy in which fertilized adult females enter a “reproductive-resting” stage during the late fall that allows them to overwinter and provide a first source of spring naupliar recruitment. This strategy has been observed in the estuarine copepod Coullana canadensis, but may also occur in other species. …


Phytoplankton Relationships To Water Quality In Lake Drummond And Two Drainage Ditches, Christine G. Phillips, Harold G. Marshall Jan 1993

Phytoplankton Relationships To Water Quality In Lake Drummond And Two Drainage Ditches, Christine G. Phillips, Harold G. Marshall

Biological Sciences Faculty Publications

A twelve-month phytoplankton study was conducted in Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Four dominant phytoplankton groups were identified at these sites. These were the Bacillariophyceae, Cyanophyceae, Cryptophyceae and an autotrophic picoplankton component. Over the past 20 years there has been a decrease in the mean pH levels of Lake Drummond and the replacement of one its former major components, the Chlorophyceae, by the Cyanophyceae. Based on water quality analysis results and species diversity indices, Lake Drummond is classified as in an early eutrophic stage of development.


Southern Nevada Effluent Wetlands: A Proposed Cooperative Venture Between The Bureau Of Reclamation & City Of Las Vegas, Bureau Of Reclamation Nov 1992

Southern Nevada Effluent Wetlands: A Proposed Cooperative Venture Between The Bureau Of Reclamation & City Of Las Vegas, Bureau Of Reclamation

Publications (WR)

Throughout North America there is a growing interest in constructed wetlands, both as relatively inexpensive, low-maintenance systems for removing nutrients from wastewater, and as a means of using municipal wastewater to enhance wildlife habitat and create public use opportunities. Because wetlands appear to have good potential as a component in the overall management of scarce water resources, the Bureau of Reclamation (Reclamation) has undertaken several cooperative research and demonstration projects to evaluate their effectiveness in a variety of local environments. While a number of projects have demonstrated that wetlands can be beneficially employed to improve water quality, few such projects …


Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski Jul 1992

Mat Movement In Coastal Louisiana Marshes: Effect Of Salinity And Inundation On Vegetation And Nutrient Levels, Christopher Martin Swarzenski

Biological Sciences Theses & Dissertations

The present research compared and contrasted the physical structure of floating and rooted marshes, their differing responses to open-water salinities and inundation, as well as the nutrient distribution in the porewaters and sediment. The effects of the physical differences in the two marsh types on the ocurrence of the dominant emergent vegetation was discussed.

The main difference in physical structure of the two marsh types was the presence of a mineral, non-buoyant layer at 25-45 cm depth in the rooted marsh, which could serve as an anchor for the overlying highly organic mat layer found in both marsh types. Porewater …


A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp Jan 1992

A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp

Watershed Sciences Faculty Publications

Between 26 April and 2 May 1992, students in a utah state university aquatic ecology class visited Lake Powell to do a study of trophic gradients of the reservoir. The main axis of the reservoir was surveyed, as well as less detailed analyses of Moki and Escalante Canyons. The work was conducted in collaboration with personnel from the u.s. Bureau of Reclamation headed by Bill Vernieu, and from the u.s. Geological Survey (Dick Marzolf). Some of their data appear in the physical-chemical section of this report.

Each student was responsible for compiling a report on one of the following specific …


Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe Jan 1992

Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe

Watershed Sciences Faculty Publications

This report outlines long-term planning and monitoring activities that occurred in 1991 and 1992 in the Stanley Basin Lakes of the upper Salmon River, Idaho for the purpose of sockeye salmon (Oncorhynchus nerka) recovery. Limnological monitoring and experimental sampling protocol, designed to establish a limnological baseline and to evaluate sockeye salmon production capability of the lakes, are present:ed. Also presented are recommended passage improvements for current fish passage barriers/impediments on migratory routes to the lakes. We initiated O. Nerka population evaluations for Redfish and Alturas lakes; this included population estimates of emerging kokanee fry entering each lake in the spring …


Phytoplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson Jan 1992

Phytoplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson

Journal of the Arkansas Academy of Science

Phytoplankton samples were collected quarterly from 1981-1990 at five stations representing discharge water from Arkansas Nuclear One, a nuclear generating station, and four "control" or "dispersal evaluation" stations. Seventy-five taxa representing five divisions were identified and enumerated. Community structure was evaluated using abundances, number of taxa, and Margalef's Richness, Shannon's Heterogeneity and Pielou's Evenness indices. No long-term trends were identified, but the beginning of cyclic variations, with a 7-year periodicity, in abundance, number of taxa, and Shannon's and Pielou's indices were apparent. Margalef's index values were constant during most of the study period. For all samples, t-tests and Mann-Whitney U …


The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin Jan 1992

The Effects Of Beaver-Created Wetlands On Surface Water Quality Of Streams And Rivers In Dupage County, Illinois, Brian Conklin

Masters Theses

Dam construction by beavers creates wetlands which have the potential to improve water quality, especially in areas near urban centers. However, beaver dams may also cause flooding problems which can result in the removal of the beaver(s) and the destruction of their dam. A further understanding of how beaver-created wetlands affect water quality will provide additional data which can be utilized in beaver management decisions.

In this study, 41 chemical parameters were examined from water taken above and below beaver-created wetlands that existed in DuPage County, Illinois between May and September 1991. This study was designed to examine the effects …


Zooplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson Jan 1992

Zooplankton Community Abundance And Diversity In Dardanelle Reservoir, Arkansas, 1981-1990, John D. Rickett, Robert L. Watson

Journal of the Arkansas Academy of Science

Zooplankton samples were collected quarterly from five stations representing the discharge bay and four "control" or "dispersing impact" stations. Rotifers dominated all samples numerically and by the number of taxa. All major groups (Rotifera, Cladocera, Copepoda, and Protozoa) exhibited greatest abundances during the summer. Quarterly variations in abundance and number of taxa were documented. Except for an increase in taxonomic analysis detail between 1981 and 1984 resulting in several more taxa added to the list, no long-term increases, declines or repeating cycles were apparent. Margalef's Richness Index reflected this change and showed a long-term increase with evidence of a 5- …


Using Physical, Chemical And Biological Indicators To Assess Water Quality On The Ouachita National Forest Utilizing Basin Area Stream Survey Methods, J. Alan Clingenpeel, Betty G. Cochran Jan 1992

Using Physical, Chemical And Biological Indicators To Assess Water Quality On The Ouachita National Forest Utilizing Basin Area Stream Survey Methods, J. Alan Clingenpeel, Betty G. Cochran

Journal of the Arkansas Academy of Science

The Ouachita National Forest (ONF) has developed a series of Best Management Practices (BMP's) designed to protect water quality and associated beneficial uses (fisheries, municipal water supplies, etc.). A monitoring program is necessary to document the effectiveness of that protection. The Basin Area Stream Survey (BASS) methodology provides a monitoring link from BMP's to the aquatic ecosystems. The goal of BASS is to identify the physical, chemical and biological characteristics of a stream in a format that will allow comparisons with other streams, and indicate when a stream is being impacted. Six index streams within two ecoregions were selected and …


A Study Of The Summer Steelhead, Oncorhynchus Mykiss In Several Intermittent Tributaries Of The Satus Creek Basin, Washington, Joel Denney Hubble Jan 1992

A Study Of The Summer Steelhead, Oncorhynchus Mykiss In Several Intermittent Tributaries Of The Satus Creek Basin, Washington, Joel Denney Hubble

All Master's Theses

The summer steelhead, Oncorhynchus mykiss population was studied in three intermittent tributaries in the Satus Creek Basin. There was a strong tendency for post emergent fry, resulting from redds located in intermittent reaches to move downstream. However, survival to perennial flow conditions was very low. Steelhead production in Dry Creek appears to be lower than in Logy Creek, because of elevated water temperatures and minimal spring and summer stream flow.


Seasonal Phytoplankton Development Within Three Rivers In The Lower Chesapeake Bay Region, Harold G. Marshall, Lewis F. Affronti Jan 1992

Seasonal Phytoplankton Development Within Three Rivers In The Lower Chesapeake Bay Region, Harold G. Marshall, Lewis F. Affronti

Biological Sciences Faculty Publications

The seasonal and inter-annual concentrations of phytoplankton were studied over a 50 month period in the lower James, York and Rappahannock Rivers (USA). Differences in the onset, duration and magnitude of major seasonal growth periods varied from year to year. There was a tendency for spring, summer and fall maxima, with a winter period of reduced abundance. An additional study of picoplankton over a 12 month period indicated greatest abundance during summer and fall, with least development in winter.


Performance Of Annual Legumes And Their Mixes Under Different Crop:Pasture Rotation., P. Evans Jan 1991

Performance Of Annual Legumes And Their Mixes Under Different Crop:Pasture Rotation., P. Evans

Experimental Summaries - Plant Research

Trial 86KA64, 86KA65 and 86KA66

Performance of annual legumes and their mixtures under different crop:pasture rotations.

Seed reserves, especially in the 1:1 rotation treatment, are on average below 100 kg/ha and in many cases below 50 kg/ha for all three soil types. Because of this the 1991 season will be used to fertilize, control weeds, and apply a grazing management system to favour legume production and seed set. No crop will be sown in 1991.

Sub clover flowering, sequential sowings.

Location: Katanning

To provide seven different temperature and photoperiod regimes, eight cultivars of sub clover ranging in maturity from Nungarin …


Littoral And Limnetic Zooplankton Communities In Lake Mead, Nevada-Arizona, Usa, Patrick J. Sollberger, Larry J. Paulson Jan 1991

Littoral And Limnetic Zooplankton Communities In Lake Mead, Nevada-Arizona, Usa, Patrick J. Sollberger, Larry J. Paulson

Publications (WR)

Zooplankton were collected from adjacent littoral and limnetic sites in Lake Mead, Nevada-Arizona, USA. Limnetic species dominated both littoral and limnetic zooplankton communities; littoral species rarely exceeded 2% of monthly total zooplankton densities. Low species richness of littoral taxa and high similarity in species composition between littoral and limnetic habitats appeared to result from uniform horizontal physical and chemical environments, due to horizontal mixing, and from the absence aquatic macrophytes. Significant differences in spatial distribution occurred in phytoplankton biomass, total zooplankton density, and fish "abundances; highest concentrations of these factors occurred nearest an inflow high in nutrients and progressively declined …


Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration Dec 1990

Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration

Publications (WR)

The Lake Mead Fertilization Project is a research program designed to investigate the potential for using large-scale artificial fertilization to enhance the game fisheries of this reservoir through an increase in the population of threadfin shad, the system's primary forage species. A substantial decline in the population of largemouth bass, together with poor condition of adult striped bass, are the two major issues affecting the Lake Mead game fisheries. Both issues have been hypothesized to be a result of an inadequate amount of forage in the reservoir. Previous studies have in turn suggested that a major factor limiting the shad …


Phytoplankton In Lake Drummond And Two Drainage Ditches In The Great Dismal Swamp, Virginia, Christine Gregory Phillips Jul 1990

Phytoplankton In Lake Drummond And Two Drainage Ditches In The Great Dismal Swamp, Virginia, Christine Gregory Phillips

Biological Sciences Theses & Dissertations

A twelve month study was conducted on the phytoplankton of Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Surface water samples were collected for nutrient and chlorophyll analysis from June 1989 to November 1989. The dominant phytoplankton component was the pico-nanoplankton (< 3 micron) category. A total of 57 species were identified from Lake Drummond, 51 species from Washington Ditch, and 31 species from the Jericho Ditch. Three major phytoplankton groups were identified at these sites: bacillariophyceans, cyanophyceans and cryptophyceans. The dominant species was the diatom Asterionella formosa. Nutrient and chlorophyll concentrations increased from summer to fall. Based on nutrient and chlorophyll g concentrations and species diversity indices, Lake Drummond is classified as eutrophic.


Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager May 1990

Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager

Publications (WR)

Procambarus clarkii are found in extremely low numbers throughout Lake Mead, AZ-NV. The crayfish are an important dietary component for game fish. Enhancement of the crayfish population would broaden the fishery forage base. Crayfish were stocked and monitored in a study cove on Saddle Island to determine if the Procambarus clarkii population could be enhanced. A trapping survey of the area after the following reproductive season yielded low numbers of crayfish. A comparison of pre-stocking and post-stocking catch per trap day (CPTD) values revealed no significant increase in the population. Procambarus clarkii growth is limited by environmental factors in Lake …


Survival Of Trout Strains As Affected By Limnological Parameters, Wayne A. Wurtsbaugh, Timothy Modde, Chris Luecke, Cheryl Courtney Mar 1990

Survival Of Trout Strains As Affected By Limnological Parameters, Wayne A. Wurtsbaugh, Timothy Modde, Chris Luecke, Cheryl Courtney

Watershed Sciences Faculty Publications

Juvenile rainbow trout Oncorhynchus mykiss. (ca. 80 mm S.L.) stocked into mid-elevation reservoirs in Utah are vulnerable to predation from piscivorous fish and birds. I determined how effectively juvenile trout used cover to avoid these predators by using direct observations (snorkel transects) on habitat selection in two reservoirs. Observations of juvenile trout were conducted within five weeks of stocking in 1988 and 1989. During the day juvenile trout were abundant in complex inshore habitats. Juvenile trout actively fed during the day but the time of peak feeding was variable. Large Daphnia made of > 95% of the diet of juvenile trout. …


Trophic Interactions Between Fish And Invertebrates In Bear Lake, Utah-Idaho, Wayne A. Wurtsbaugh, Charles P. Hawkins Mar 1990

Trophic Interactions Between Fish And Invertebrates In Bear Lake, Utah-Idaho, Wayne A. Wurtsbaugh, Charles P. Hawkins

Watershed Sciences Faculty Publications

An intensive study of the limnology, invertebrates and fishes of Bear Lake was conducted in 1987 in order to define the productivity and food web of the community. Limno10gica1 parameters and invertebrates were measured at approximately monthly intervals while fish distribution and feeding was analyzed in February, June, August, and October. Samples were collected at three to eight stations along a transect running from the shallow littoral area on the west side of the lake, to the deep profundal zone.