Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Fresh Water Studies

PDF

2001

Articles 1 - 7 of 7

Full-Text Articles in Ecology and Evolutionary Biology

Trophic Cascades, Nutrients, And Lake Productivity: Whole-Lake Experiments, Stephen R. Carpenter, Jonathan J. Cole, James R. Hodgson, James F. Kitchell, Michael L. Pace, Darren Bade, Kathryn L. Cottingham May 2001

Trophic Cascades, Nutrients, And Lake Productivity: Whole-Lake Experiments, Stephen R. Carpenter, Jonathan J. Cole, James R. Hodgson, James F. Kitchell, Michael L. Pace, Darren Bade, Kathryn L. Cottingham

Dartmouth Scholarship

Responses of zooplankton, pelagic primary producers, planktonic bacteria, and CO2 exchange with the atmosphere were measured in four lakes with contrasting food webs under a range of nutrient enrichments during a seven-year period. Prior to enrichment, food webs were manipulated to create contrasts between piscivore dominance and planktivore dominance. Nutrient enrichments of inorganic nitrogen and phosphorus exhibited ratios of N:P > 17:1, by atoms, to maintain P limitation. An unmanipulated reference lake, Paul Lake, revealed baseline variability but showed no trends that could confound the interpretation of changes in the nearby manipulated lakes. Herbivorous zooplankton of West Long Lake (piscivorous fishes) …

Go to article

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 …

Go to article

Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio Jan 2001

Vitellogenin -- A Biomarker Of Exposure To Environmental Estrogens For Mummichog (Fundulus Heteroclitus) From A Creosote-Contaminated Site?, Sara Mirabilio

Dissertations, Theses, and Masters Projects

Vitellogenin (VTG) is widely used as a biomarker for environmental estrogens and reproductive disruption in fish. Vitellogenesis is the process by which yolk is formed. The endpoint is most sensitive in male fish where vitellogenesis is an abnormal process. Research examining effects of environmental mixtures of chemicals (e.g. creosote) on vitellogenesis is limited. This study examines plasma VTG expression in both male and female mummichog, Fundulus heteroclitus, collected from a creosote-contaminated site and two reference sites in lower Chesapeake Bay, USA, and in wild-caught male reference fish exposed in the laboratory to creosote-contaminated sediment. Further, this study uses tissue somatic …

Go to article

Nursery Delineation, Habitat Utilization, Movements, And Migration Of Juvenile Carcharhinus Plumbeus In Chesapeake Bay, Virginia, United States Of America, R. Dean. Grubbs Jan 2001

Nursery Delineation, Habitat Utilization, Movements, And Migration Of Juvenile Carcharhinus Plumbeus In Chesapeake Bay, Virginia, United States Of America, R. Dean. Grubbs

Dissertations, Theses, and Masters Projects

Chesapeake Bay is possibly the largest summer nursery for Carcharhinus plumbeus in the western Atlantic. Longline sampling conducted from 1990--1999 was used to delineate this nursery spatially and temporally. Catch data from 83 longline stations sampled throughout the Virginia Chesapeake Bay were analyzed as a function of nine physical and environmental variables to delineate this nursery spatially. Tree-based models determined which variables best discriminated between stations with high and low catches and indicated that complex distribution patterns could be adequately modeled with few variables. The highest abundance of juvenile sharks was predicted where salinity was greater than 20.5 and depth …

Go to article

Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez Jan 2001

Heat Shock Protein (Hsp70) Response In The Eastern Oyster, Crassostrea Virginica, Exposed To Various Contaminants (Pahs, Pcbs And Cadmium), Luis A. Cruz Rodriguez

Dissertations, Theses, and Masters Projects

The stress protein response has been proposed as a general indicator of exposure to stress as their expression might integrate overall biological impact and interactions among multiple stressors. as a marker of contaminant effects, a major advantage is the premise of higher sensitivity over other indices such as condition index, scope for growth and survival. Laboratory exposure to suspended field contaminated sediments (SFCS) elicited a stress protein response (HSP70) in the eastern oyster, ( Crassostrea virginica). The stress response probably resulted from the combined effect of various contaminants including PAHs, metals and PCBs. Exposure to 1--2g suspended clay particles spiked …

Go to article

Hydrogeological Characterization Of The South Oyster Bacterial Transport Site Using Geophysical Data, Susan S. Hubbard, Jinsong Chen, John Peterson, Ernest L. Majer, Kenneth H. Williams, Donald J. Swift, Brian Mailloux, Yoram Rubin Jan 2001

Hydrogeological Characterization Of The South Oyster Bacterial Transport Site Using Geophysical Data, Susan S. Hubbard, Jinsong Chen, John Peterson, Ernest L. Majer, Kenneth H. Williams, Donald J. Swift, Brian Mailloux, Yoram Rubin

OES Faculty Publications

A multidisciplinary research team has conducted a field-scale bacterial transport study within an uncontaminated sandy Pleistocene aquifer near Oyster, Virginia. The overall goal of the project was to evaluate the importance of heterogeneities in controlling the field-scale transport of bacteria that are injected into the ground for remediation purposes. Geochemical, hydrological, geological, and geophysical data were collected to characterize the site prior to conducting chemical and bacterial injection experiments. In this paper we focus on results of a hydrogeological characterization effort using geophysical data collected across a range of spatial scales. The geophysical data employed include surface ground-penetrating radar, radar …

Go to article

The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen Jan 2001

The Impact Of Marine Reserves On Exploited Species With Complex Life Histories: A Modeling Study Using The Caribbean Spiny Lobster In Exuma Sound, Bahamas, William T. Stockhausen

Dissertations, Theses, and Masters Projects

Most benthic invertebrates and reef-associated fish undergo a dispersive, planktonic larval stage prior to settlement and metamorphosis into the juvenile and adult stages. In some species, settlement may be decoupled from adult abundance at local spatial scales if hydrodynamic conditions or larval behavior do not promote local retention. Similarly, spatial variability in postsettlement mortality or secondary dispersal by juveniles and adults may decouple spatial patterns of adult abundance from those of settlement. as a consequence, spatial patterns of settlement and adult abundance may be functionally related in a complex fashion. Whether biotic/environmental factors control spatial patterns of abundance may have …

Go to article