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Full-Text Articles in Ecology and Evolutionary Biology

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 …


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


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 …


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.


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.


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.


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 …


Phytoplankton Ecology And Dynamics In The James River Estuary Virginia, U. S. A., Margaret J. Filardo Apr 1984

Phytoplankton Ecology And Dynamics In The James River Estuary Virginia, U. S. A., Margaret J. Filardo

OES Theses and Dissertations

Autotrophic biomass and productivity as well as nutrient distributions and phytoplankton cell populations in the James River estuary, Virginia, from Newport News Shipyard to the 0 o/oo isohaline, were sampled on a monthly basis from August of 1981 to December of 1982. Particular emphasis was placed on the very low salinity region (defined as the location where surface salinity measured between 0.0 and 0.75 o/oo based on conductivity) in order to determine the fate of fresh water phytoplankters upon being advected into the estuary because of their suspected role in the biogeochemical cycling that occurs there.

Both chlorophyll a and …


Factors Effecting Phytoplankton Assemblages In The Lafayette River Estuary, Laurie Ann Kalenak Oct 1982

Factors Effecting Phytoplankton Assemblages In The Lafayette River Estuary, Laurie Ann Kalenak

OES Theses and Dissertations

Chemical and physical parameters were measured with phytoplankton species composition and abundance in the Lafayette River from August to October 1981. Stations located in four distinct areas of the river were statistically analyzed to determine data relationships. Environmental factors considered as potentially influencing the presence and numbers of phytoplankton were salinity, temperature, Secchi depth, tidal phase, orthophosphate, combined nitrates and nitrites, ammonia, and reactive silicates.

The River mouth had higher salinity and nutrient values, with lower temperatures than the other river sections. Diatoms were the dominant cells in this section of the River. At mid-river, salinity and nutrient concentrations decreased, …


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.


Limnological Aspects Of Lake Mead, Nevada-Arizona, John R. Baker, James E. Deacon, Thomas A. Burke, Samuel S. Egdorf, Larry J. Paulson, Richard W. Tew, Bureau Of Reclamation Jun 1977

Limnological Aspects Of Lake Mead, Nevada-Arizona, John R. Baker, James E. Deacon, Thomas A. Burke, Samuel S. Egdorf, Larry J. Paulson, Richard W. Tew, Bureau Of Reclamation

Publications (WR)

Lake Mead is a deep, subtropical, moderately productive, desert impoundment with a negative heterograde oxygen profile occurring during; the summer stratification. investigations of the Boulder Basin of Lake Mead by the University of Nevada were initiated in November 1971. The primary objective of the study was to determine what effects industrial and sewage effluent from the Las Vegas metropolitan area, discharged into Las Vegas Bay, have had on the water quality and limnological conditions of Boulder Basin. Data from the 1975-76 period are presented in detail, with earlier data included in the summaries and discussions.

Measurements of water temperature, dissolved …


A Review Of The Limnology Of And Water Quality Standards For Lake Mead, Charles R. Goldman Oct 1976

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 …


An Evaluation Of The Effects Of Dredging Within The Arkansas River Navigation System, Volume Iii-The Effects Upon The Zooplankton Associations, Edgar D. Short, Eugene H. Schmitz Jan 1976

An Evaluation Of The Effects Of Dredging Within The Arkansas River Navigation System, Volume Iii-The Effects Upon The Zooplankton Associations, Edgar D. Short, Eugene H. Schmitz

Technical Reports

The primary purpose of the zooplankton phase of the coordinated study was to attempt to evaluate the effects of dredging operations on the abundance, distribution, composition and complexity of the zooplankton communities within the aquatic system of the Arkansas River. The other phases of investigation include fish, macroinvertebrates, phytoplankton and some physico-chemical parameters. The lack of baseline data, needed for measurement of previous ecological conditions from which to detect past and future changes, proved to be a major impediment to any evaluation. Although the study involved only about 240 miles of the river in Arkansas, it should serve as an …


Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki May 1975

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 …


Limnological, Ichthyological, And Parasitological Investigations On Arkansas Reservoris In Relation To Water Quality, John S. Carter, Carl E. Hoffman, Larry L. Olmsted, Raj V. Kilambi, Donald G. Cloutman, David A. Becker Jan 1974

Limnological, Ichthyological, And Parasitological Investigations On Arkansas Reservoris In Relation To Water Quality, John S. Carter, Carl E. Hoffman, Larry L. Olmsted, Raj V. Kilambi, Donald G. Cloutman, David A. Becker

Technical Reports

Lake Fort Smith, a 525 acre (212 ha) reservoir, was impounded in 1936 as a water supply for the city of Fort Smith. The reservoir is located on Clear Creek (Frog Bayou), a tributary of the Arkansas River, in the Boston Mountains 28 miles (45 km) northeast of the city of Fort Smith in Crawford County, Arkansas. A map and morphometric characteristics of Lake Fort Smith are given in Fig. 1 and Table I (Hoffman, 1951; Nelson, 1952). In 1956 Lake Shepherd Springs, a 750 acre (304 ha) impoundment, was created one mile upstream of Lake Fort Smith (Rorie, 1961). …


Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett Jan 1974

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 Jan 1974

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 Composition At Lake Drummond In The Dismal Swamp, Virginia, William Howard Poore Jr. Jul 1971

Phytoplankton Composition At Lake Drummond In The Dismal Swamp, Virginia, William Howard Poore Jr.

Biological Sciences Theses & Dissertations

Abstract unavailable.