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Full-Text Articles in Ecology and Evolutionary Biology

The Importance Of Winter Dinoflagellate Blooms In Chesapeake Bay— A Missing Link In Bay Productivity, Nicole C. Millette, Sophie Clayton, Margaret R. Mulholland, Leah Gibala-Smith, Michael Lane Jan 2023

The Importance Of Winter Dinoflagellate Blooms In Chesapeake Bay— A Missing Link In Bay Productivity, Nicole C. Millette, Sophie Clayton, Margaret R. Mulholland, Leah Gibala-Smith, Michael Lane

OES Faculty Publications

It is widely assumed that phytoplankton abundance and productivity decline during temperate winters because of low irradiance and temperatures. However, winter phytoplankton blooms commonly occur in temperate estuaries, but they are often undocumented because of reduced water quality monitoring in winter. The small body of in situ work that has been done on winter blooms suggests they can be of enormous consequence to ecosystems. However, because monitoring is often reduced or stopped altogether during winter, it is unclear how widespread these blooms are or how long they can last. We analyzed an over 30-year record of monthly phytoplankton monitoring samples …


Assessing Chemical And Biological Recovery From Acid Rain Deposition In Montane Vermont Lakes, Sydney Diamond Jan 2021

Assessing Chemical And Biological Recovery From Acid Rain Deposition In Montane Vermont Lakes, Sydney Diamond

Graduate College Dissertations and Theses

Vermont’s inland lakes are changing rapidly in response to anthropogenic disturbance pressures. While changes in water chemistry are well documented across the state, the biological response of primary producer communities to these shifts remains poorly understood. This project investigated the response of phytoplankton communities to the interacting effects of recovery from acidification and climate change in high-altitude lakes. We analyzed long-term monitoring and meteorological data in four of Vermont’s acid-impaired lakes and found that as pH and acid-neutralizing capacity has increased, so have concentrations of dissolved organic carbon (DOC) in most lakes. To assess the biological response to these processes, …


Water Quality Assessment In The Occurrence Of Acanthaster Spp. (Crown-Of-Thorns Starfish, Cots) On Coral Reefs In Menjangan Island, Bali, Indonesia, Novia Arinda Pradisty, Eghbert Elvan Ampou, Rizki Hanintyo Sep 2020

Water Quality Assessment In The Occurrence Of Acanthaster Spp. (Crown-Of-Thorns Starfish, Cots) On Coral Reefs In Menjangan Island, Bali, Indonesia, Novia Arinda Pradisty, Eghbert Elvan Ampou, Rizki Hanintyo

Makara Journal of Science

Aquatic stressors are known to cause biological impairment that can result in biodiversity loss in several Marine Protected Areas (MPA), including in Menjangan Island, West Bali National Park. The objectives of this study were to correlate the changes in water quality parameters with the biological effect of Crown-of-Thorns starfish (CoTS) population dynamics and to assess the most applicable parameters for continuous environmental monitoring. Field observations and surveys were conducted three times in 2017, during the wet season, dry season and season transition, in order to assess the effect of seasonal variability. Redundancy Analysis (RDA) was performed to determine the relationship …


The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev Sep 2019

The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a collective prediction among ecologists that climate change will enhance phytoplankton biomass in temperate lakes. Yet there is noteworthy variation in the structure and regulating functions of lakes to make this statement challengeable and, perhaps, inaccurate. To generate a common understanding on the trophic transition of lakes, I examined the interactive effects of climate change and landscape properties on phytoplankton biomass in 12,644 lakes located in relatively intact forested landscapes. Chlorophyll-a (Chl-a) concentration was used as a proxy for phytoplankton biomass. Chl-a concentration was obtained via analyzing Landsat satellite imagery data over a 28-year period (1984-2011) and using …


Long-Term Monitoring In Central Puget Sound: Are Local Climate Anomalies Impacting Phytoplankton Populations?, Gabriela Hannach, Lyndsey M. Swanson, Kimberle Stark Apr 2018

Long-Term Monitoring In Central Puget Sound: Are Local Climate Anomalies Impacting Phytoplankton Populations?, Gabriela Hannach, Lyndsey M. Swanson, Kimberle Stark

Salish Sea Ecosystem Conference

Puget Sound is a large and productive estuarine system at the southern end of the Salish Sea. King County’s comprehensive, long-term marine monitoring program tracks water quality in Puget Sound’s Central Basin through year-round collection of data for a suite of physical, chemical and biological parameters. Phytoplankton monitoring began with traditional microscopy methods in 2008, and expanded to include a particle imaging system in 2014. These data are critical to assess how changes from climate, physical conditions and other stressors linked to anthropogenic activity from the region’s growing population may impact the Sound’s biodiversity and trophic structure. Currently, twice-monthly surface …


Seasonal Dynamics Of Oceanographic Conditions, Phytoplankton, And Zooplankton In The Malaspina Strait, Strait Of Georgia, Svetlana Esenkulova, Karyn Suchy, Richard Ian Perry, Kelly Young, Maycira Costa, Ryan Flagg, Moira Galbraith, Isobel Pearsall Apr 2018

Seasonal Dynamics Of Oceanographic Conditions, Phytoplankton, And Zooplankton In The Malaspina Strait, Strait Of Georgia, Svetlana Esenkulova, Karyn Suchy, Richard Ian Perry, Kelly Young, Maycira Costa, Ryan Flagg, Moira Galbraith, Isobel Pearsall

Salish Sea Ecosystem Conference

Plankton dynamics in the Salish Sea may directly impact resident and migratory fish populations that are of major economic importance in the region. The Malaspina Strait in the northern Salish Sea is of particular interest as it is an important migration route for juvenile salmon. Here, we present data collected at three stations in the Malaspina Strait as part of the Citizen Science initiative of the Salish Sea Marine Survival Project. Sampling was conducted at bi-monthly (or higher) frequency from February to October, 2015 to 2017. Relationships between the regional hydrography, environmental parameters (temperature, salinity, dissolved oxygen, etc.), nutrient concentrations, …


Salish Sea Model Ecosystem - Lower Trophic: Episodic Nutrient Supply In The Northern Strait Of Georgia, Elise Olson, Susan E. Allen Apr 2018

Salish Sea Model Ecosystem - Lower Trophic: Episodic Nutrient Supply In The Northern Strait Of Georgia, Elise Olson, Susan E. Allen

Salish Sea Ecosystem Conference

Salish Sea Model Ecosystem - Lower Trophic (SMELT) is a three-dimensional biogeochemical model coupled to a NEMO-based physical model of the Salish Sea, run operationally at UBC as part of the SalishSeaCast system. In this presentation, we will first establish the model's skill at reproducing nitrate concentrations by comparison with data from the Pacific Salmon Foundation’s citizen science program and Institute of Ocean Sciences repeat surveys. We will then discuss episodic nitrate supply to the surface waters of the northwest Strait of Georgia. This phenomenon is evident as a region of elevated mean (March-November) and standard deviation (April-September) of surface …


How Did Large Scale Climate Anomalies Impact 2015 Phytoplankton Blooms In Puget Sound?, Juhi Lafuente, Christopher Krembs, S. L. Albertson, Allison Brownlee, Julia Bos, Laura Hermanson, Mya Keyzers Apr 2018

How Did Large Scale Climate Anomalies Impact 2015 Phytoplankton Blooms In Puget Sound?, Juhi Lafuente, Christopher Krembs, S. L. Albertson, Allison Brownlee, Julia Bos, Laura Hermanson, Mya Keyzers

Salish Sea Ecosystem Conference

The Washington State Department of Ecology has been routinely monitoring marine water quality throughout the Puget Sound since 1973. An established historic baseline from 1999 to 2008 allows us to examine how water quality varies year to year as a result of both natural and human influences. The recent large scale climate anomaly, the Blob, impacted this region when a mass of warm water entered Puget Sound in fall 2014. In conjunction with higher than normal air temperatures, patterns of estuarine circulation and stratification were regionally altered in Puget Sound. Changes to these physical patterns affect ecosystem functions starting at …


Soundtoxins: A Puget Sound Harmful Algae Monitoring Partnership, Teri King, Lyndsey Claassen, Jerry Borchert, Vera Trainer Apr 2018

Soundtoxins: A Puget Sound Harmful Algae Monitoring Partnership, Teri King, Lyndsey Claassen, Jerry Borchert, Vera Trainer

Salish Sea Ecosystem Conference

SoundToxins is a diverse partnership of aquaculture businesses, federal, tribal, state, and local governments, education institutions, and Puget Sound residents that monitor for harmful algae in Puget Sound, managed by NOAA’s Northwest Fisheries Science Center and Washington Sea Grant. The intensively trained partners provide early warning of harmful algal bloom (HAB) events by evaluating water samples gathered weekly from 35 stations throughout Puget Sound looking specifically for Dinophysis, Alexandrium, Pseudo-nitschia and Azadinium and alerting health and natural resource agencies of their presence and concentration. The online database and mapping allows for near-real time viewing of data entered by SoundToxins partners …


Has Primary Productivity Declined In The Strait Of Georgia Since The 1970s?, Sophia Johannessen Apr 2018

Has Primary Productivity Declined In The Strait Of Georgia Since The 1970s?, Sophia Johannessen

Salish Sea Ecosystem Conference

A strong decline in phytoplankton productivity has been proposed as a principal cause of the decline in salmon survival in the Strait of Georgia over the last four decades. The best estimate of total annual primary productivity in the Strait in the 1970s was 280 gC m-2 yr-1 (Harrison et al., 1983). We tested whether or not primary productivity had declined since that time by calculating recent productivity from regional nitrogen budgets. We constructed the budgets using measurements (collected 2001-2011) of dissolved and particulate nitrogen and stable isotopes of nitrogen in seawater, river water, sinking particles, bottom sediments, atmospheric deposition, …


Harmful Algae In The Strait Of Georgia, Citizen Science Data, Svetlana Esenkulova, Isobel Pearsall Apr 2018

Harmful Algae In The Strait Of Georgia, Citizen Science Data, Svetlana Esenkulova, Isobel Pearsall

Salish Sea Ecosystem Conference

The Citizen Science Program was initiated by the Pacific Salmon Foundation, Fisheries and Oceans Canada, and Ocean Networks Canada in 2015. This Program was designed to achieve oceanographic monitoring of the Strait of Georgia on temporal and spatial scale that had never been done before. Samples and measurements were taken at approximately 80 sites on a bi-monthly (or higher) frequency from February to October, 2015 to 2017. This presentation will be focused on the spatial and temporal distribution of harmful algae based on the analysis of about 5000 phytoplankton samples. Preliminary results indicate that during the sampling period in the …


Associated Dataset: Climate Change Impacts On Southern Ross Sea Phytoplankton Composition, Productivity And Export, Daniel E. Kaufman, Marjorie A.M. Friedrichs, Walker O. Smith Jr., Eileen E. Hofmann, Michael S. Dinniman, John C.P. Hemmings Jan 2017

Associated Dataset: Climate Change Impacts On Southern Ross Sea Phytoplankton Composition, Productivity And Export, Daniel E. Kaufman, Marjorie A.M. Friedrichs, Walker O. Smith Jr., Eileen E. Hofmann, Michael S. Dinniman, John C.P. Hemmings

Data

This dataset includes data used in the publication Kaufman et al., 2017, JGR-Oceans, which investigates how these climatic changes in the Ross Sea, Antarctica, may alter phytoplankton composition, primary productivity and export. A one-dimensional version of the Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was adapted for use in the Ross Sea (MEDUSA-RS). Glider measurements were used to force MEDUSA-RS, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance was evaluated with glider observations, and experiments were conducted using projections of physical drivers for mid- and late-21st century. Additional scenarios examined the …


Sea Surface Temperature Rises Shift Migration Patterns Due To Ecosystem Changes, Alexia Skrbic, Hesham El-Askary Dec 2016

Sea Surface Temperature Rises Shift Migration Patterns Due To Ecosystem Changes, Alexia Skrbic, Hesham El-Askary

Student Scholar Symposium Abstracts and Posters

The continuing climate change is negatively impacting ecosystems, specifically oceans which are declining and food webs are being altered by the increase of greenhouse gases. The increase of the carbon dioxide and other greenhouse gases is increasing sea surface temperature of the world’s oceans. Certain organisms lower on the food chain like phytoplankton and zooplankton are directly affected by the warming which alters how they process nutrients and their productivity. The limited amount of these primary producers in the oceans and specifically the location they inhabit directly affects all the organisms above them on the food chain. Several marine animals …


Exploration Of Spatial And Temporal Changes In Trophic Status Of Lakes In The Northern Temporal Forest Biome Using Remote Sensing, Aleksey Paltsev Apr 2015

Exploration Of Spatial And Temporal Changes In Trophic Status Of Lakes In The Northern Temporal Forest Biome Using Remote Sensing, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a critical need for detailed surveys of lakes covering large spatial (>100 km2) and temporal scales (decades) to determine if there is an increase in the magnitude and frequency of phytoplankton blooms. Remote sensing was used to: (1) develop a regression model that relates chlorophyll a (chl-a) as a proxy of lake phytoplankton biomass to Landsat TM and ETM+ optical reflectance (r2=0.85, p


How The Presence Of Plastic In The North Pacific Gyre Affects The Growth Of Thalassiosira Through Remote Sensing And Laboratory Replication, Jordynn Brennan, Hesham El-Askary Dec 2014

How The Presence Of Plastic In The North Pacific Gyre Affects The Growth Of Thalassiosira Through Remote Sensing And Laboratory Replication, Jordynn Brennan, Hesham El-Askary

Student Scholar Symposium Abstracts and Posters

Through the use of remote sensing, we are able to determine the approximate location of the garbage patch in the North Pacific Gyre. Though remote sensing does not penetrate the surface of the ocean, monthly satellite images can be analyzed to determine the rate of growth or rate of decrease of certain parameters, such as atmospheric gases, phytoplankton, and dissolved organic matter. Over the past decade, data from the Goddard Earth Sciences Data and Information Services Center (Giovanni program) has shown a significant increase in dissolved organic matter and chlorophyll a content in the area of the North Pacific Garbage …


Benthic And Planktonic Microalgal Community Structure And Primary Productivity In Lower Chesapeake Bay, Matthew Reginald Semcheski Apr 2014

Benthic And Planktonic Microalgal Community Structure And Primary Productivity In Lower Chesapeake Bay, Matthew Reginald Semcheski

Biological Sciences Theses & Dissertations

Microalgal populations are trophically important to a variety of micro- and macroheterotrophs in marine and estuarine systems. In Chesapeake Bay, microalgae facilitate the survival and development of ecologically and economically relevant fauna, including shellfish and finfish populations. While regarded as significant components of coastal environments, microphytobenthic communities are historically understudied. In Chesapeake Bay, the importance of phytoplankton to the ecosystem is understood, but the contribution of microphytobenthos remains unclear. This project surveys intertidal microphytobenthic communities, in relation to phytoplankton communities, around lower Chesapeake Bay describing the taxonomic makeup of these populations, coupled with quantification of cell abundance, biomass, and primary …


Investigations Of Phytoplankton Diversity In Chesapeake Bay, Todd Arthur Egerton Apr 2013

Investigations Of Phytoplankton Diversity In Chesapeake Bay, Todd Arthur Egerton

Biological Sciences Theses & Dissertations

Characterizing the diversity of a community in relation to environmental conditions and ecosystem functions are core concepts in ecology. While decades of research have led to a growing comprehension of diversity in many ecosystems, our understanding in aquatic habitats and microbial organisms remains relatively limited. Phytoplankton represent a diverse and important group that contribute approximately half of global primary productivity and are intrinsically connected to changing environmental conditions, especially in systems as dynamic as estuaries. To better understand the ecological processes governing phytoplankton composition and diversity, spatial and temporal patterns of environmental parameters and their relation to the algal community …


Invasive Predator, Bythotrephes, Has Varied Effects On Ecosystem Function In Freshwater Lakes, Angela L. Strecker, Shelley E. Arnott Jan 2008

Invasive Predator, Bythotrephes, Has Varied Effects On Ecosystem Function In Freshwater Lakes, Angela L. Strecker, Shelley E. Arnott

Environmental Science and Management Faculty Publications and Presentations

Bythotrephes longimanus is an invertebrate predator that has invaded the North American Great Lakes and a number of inland lakes, where it preys on crustacean zooplankton. We examined the effect of Bythotrephes on two measures of ecosystem function during a four month observational study of freshwater lakes on the boreal shield. Bythotrephes-invaded lakes had significantly lower epilimnetic zooplankton abundance and production compared to reference lakes. On average, Bythotrephes consumed 34% ofzooplankton production when it was present in lakes. There was some evidence of changes in the timing of zooplankton production, as well as shifts to cooler, less productive habitats, which …


A Comparison Of Phytoplankton Communities In Lake Prince And The Western Branch Reservoir, Suffolk, Virginia, Cara Marie Muscio Apr 2001

A Comparison Of Phytoplankton Communities In Lake Prince And The Western Branch Reservoir, Suffolk, Virginia, Cara Marie Muscio

Biological Sciences Theses & Dissertations

Lake Prince and the Western Branch Reservoir are two eutrophic bodies of water located in Suffolk, Virginia. Lake Prince and its two small tributaries join the Western branch via a constructed spillway. This lake system is a source of water for the surrounding municipalities, and a recreational area for community citizens. In the past, these bodies of water had repeated incidents of low oxygen and nuisance algal blooms, particularly cyanobacteria species. As a result aerators have been installed in the main body of both Lake Prince and the Western Branch Reservoir. In addition, a pipeline has been installed from North …


Benthic Microalgal Production At Stellwagen Bank, Massachusetts Bay, Usa, Lawrence B. Cahoon, Guy R. Beretich Jr., Carrie J. Thomas, Amy M. Mcdonald Jan 1993

Benthic Microalgal Production At Stellwagen Bank, Massachusetts Bay, Usa, Lawrence B. Cahoon, Guy R. Beretich Jr., Carrie J. Thomas, Amy M. Mcdonald

OES Faculty Publications

Benthic microalgal chlorophyll a and production were measured at 3 sites at Stellwagen Bank, a cold temperate continental shelf habitat in Massachusetts Bay, USA, during August 1991. Benthic microalgal chlorophyll a averaged 39.8 Mg M-2, vs average integrated phytoplankton chlorophyll a of 25.9 mg m-2. Gross benthic microalgal production, measured by oxygen exchange in clear and opaque benthic chambers, averaged 20.9 mg C m-2 h-1. This production was supported by average daily light fluxes to the bottom that never exceeded 1 % of surface incident radiation and were as low as 4.7 μE …


Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation Nov 1987

Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation

Publications (WR)

Studies conducted by the University of Nevada-Las Vegas (UNLV), the Nevada Department of Wildlife (NDOW), the Arizona Game and Fish Department (AGFD), The Nevada Division of Environmental Protection (NDEP), and the United States Bureau of Reclamation (USBR) have identified decreased algal production as a major factor involved in the decline of the Lake Mead sport fishery. Phosphorus-laden silt particles in the Colorado River have been sedimenting out in Lake Powell since the completion of Glen Canyon Dam 286 miles upstream in 1963. This sharp decrease in phosphorus loading to Lake Mead (>5000 tons per year) has resulted in decreased …


A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson Nov 1984

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m3. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m3. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …


Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde May 1984

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 May 1984

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 …


Algal Dynamics In A Cypress Stand In The Seasonally Flooded Great Dismal Swamp, Joseph A. Atchue Iii Oct 1981

Algal Dynamics In A Cypress Stand In The Seasonally Flooded Great Dismal Swamp, Joseph A. Atchue Iii

Biological Sciences Theses & Dissertations

The dynamics of epiphytic algae and phytoplankton were studied at a cypress stand in the Great Dismal Swamp, Virginia. Mean epiphytic algal biomass was 19.9 g m-2 and mean planktonic biomass was 3.4 g m-2.Nutrient concentrations in the epiphytic algae and the litter were determined. The algae had mean concentrations of 1.67% and 0.18%. They were found to immobilize as much as 0.5 g N m-2 and 0.06 g P m-2. This suggests that the algae are important as nutrient conservers. The phytoplankton were composed primarily of Bacillariophyceae. They exhibited a more or less …


Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson Dec 1980

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

Publications (WR)

This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …


Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson Jun 1980

Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …


Evaluation Of Impacts Associated With Reregulation Of Water Levels In Lake Mohave, Larry J. Paulson, John R. Baker, U.S. Water And Power Resources Service Mar 1980

Evaluation Of Impacts Associated With Reregulation Of Water Levels In Lake Mohave, Larry J. Paulson, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The U.S. Water and Power Resources Service is considering reregulating Lake Mohave water levels to increase the net power benefit from Hoover Dam. Reregulation will not increase the generation capacity of the Hoover powerplant but it will enable the plant operation to be increased when the energy has greater monetary value. Energy generated at different times of the year has different market value, the highest being in January-March and July- September. By generating more power during these periods more net monetary benefit can be derived from Hoover Dam. The total volume of water released from Hoover Dam over an annual …


Influence Of Dredging And High Discharge On The Ecology Of Black Canyon, Larry J. Paulson, Theron G. Miller, John R. Baker, U.S. Water And Power Resources Service Jan 1980

Influence Of Dredging And High Discharge On The Ecology Of Black Canyon, Larry J. Paulson, Theron G. Miller, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The Water and Power Resources Service is considering dredging in Black Canyon to create a larger forebay to accommodate higher peak discharges and reverse flows for proposed modifications to Hoover Dam.

The Black Canyon area from Hoover Dam to Willow Beach supports a heavily utilized trout fishery and is important habitat for the razorback sucker (Xyrauchen texanus) and possibly bonytail chub (Gila elegans).

The Water and Power Resources Service initiated this investigation to determine what effect dredging and higher peak-discharges would have on the ecology of Black Canyon.


A Limnological Study Of 43 Selected Maine Lakes, Derrill J. Cowing, Matthew Scott Jan 1980

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