Terrestrial and Aquatic Ecology Commons^™

Recruitment In Degraded Marine Habitats: A Spatially Explicit, Individual-Based Model For Spiny Lobster, Mark J. Butler Iv, Thomas W. Dolan Iii, John H. Hunt, Kenneth A. Rose, William F. Herrnkind

Biological Sciences Faculty Publications

Coastal habitats that serve as nursery grounds for numerous marine species are badly degraded, yet the traditional means of modeling populations of exploited marine species handle spatiotemporal changes in habitat characteristics and life history dynamics poorly, if at all. To explore how nursery habitat degradation impacts recruitment of a mobile, benthic species, we developed a spatially explicit, individual-based model that describes the recruitment of Caribbean spiny lobster (Panulirus argus) in the Florida Keys, where a cascade of environmental disturbances has reconfigured nursery habitat structure. In recent years, the region has experienced a series of linked perturbations, among them, seagrass die-offs, …

Morphological And Molecular Defects In Zebrafish Embryos (Danio Rerio) After Chromated Copper Arsenate Exposure, Kerry Jean Lee

Biological Sciences Theses & Dissertations

This investigation identified the morphological defects caused by different concentrations of chromium, copper, and arsenic (CCA) on the developing zebrafish embryo; in addition to defects caused by the three combined components (complete CCA). A change in the DNA of the developing embryos in response to the three components of CCA and complete CCA was also determined. Early Dania rerio embryos were cultured for five days with various concentrations of CCA components and complete CCA. Morphological defects were assessed with light microscopy and DNA fragmentation was determined by agarose gel electrophoresis. Embryonic exposure of D. rerio to sub lethal concentrations of …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Peter L. Morton, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2004), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Peter L. Morton, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

A marked decline in the water quality of the Chesapeake Bay has occurred over the past several decades. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality. The results of concentrated research efforts in the late 1970s and early 1980s stimulated the establishment of Federal and state directives to better manage the Chesapeake Bay watershed. By way of the …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2003), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below.

In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2003), Daniel M. Dauer

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. Findings from the last 18 years of the monitoring programs are highlighted below. In 1995, the Virginia DEQ instituted changes to its analytical techniques for …

Benthic Fisheries Ecology In A Changing Environment: Unraveling Process To Achieve Prediction, Mark J. Butler Iv

Biological Sciences Faculty Publications

Marine fisheries and the ecosystems that sustain them are increasingly beset by environmental deterioration, and the problem is particularly acute in coastal zones where human Populations are increasing. In the best of circumstances, fishery managers are faced with the multiple, often conflicting, demands of resource users, politicians, and scientists when considering strategies for resource management. A further challenge is that management decisions must be made against a backdrop of a deteriorating environment and the shifting status of coastal ecosystem integrity. Traditional tools for single-species management may be inadequate in these settings. Furthermore. the necessary empirical data to appropriately parameterize models …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2003), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

Macrobenthic communities of the Elizabeth River watershed have been quantitatively sampled since summer 1999. This report presents the data from the fifth year of sampling in 2003. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. ( 2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will be updated …

Strong Interactions Between Juvenile Caribbean Spiny Lobster (Panulirus Argus) And Caribbean Reef Octopus (Octopus Briareus) In The Florida Keys, Jennifer Anne Lear

Biological Sciences Theses & Dissertations

Coexisting species may simultaneously compete for resources and interact as predator and prey, creating a strong interaction that can alter the structure of animal communities. This type of interaction potentially occurs between juvenile Caribbean spiny lobster (Panulirus argus) and Caribbean reef octopus (Octopus briareus) within hard-bottom habitats in the Florida Keys, FL (USA), where octopuses may consume juvenile lobsters and also compete with them for limited crevice shelters. I conducted a series of field and mesocosm studies to investigate the nature of octopus-lobster interactions and their implications for the structure of their populations in the wild. …

Seed Bank Response To Fire And Successional Trajectory Of A Virginia Small Depression Pocosin, Jay F. Bolin

Biological Sciences Theses & Dissertations

Pocosins are depressional wetlands maintained by fire. Plants in fire adapted systems can use a variety of mechanisms for survival and recruitment. I examined the seed bank response to fire (500 to 700 °C) and wet heat treatments (50 and 75 °C) in a Virginia small depression pocosin. I quantified seedling abundance, richness, and Sphagnum density. Extant vegetation was sampled with a nested plot design at each seed bank sampling area. The seed flora was compared with the extant vegetation at three size classes with Sorenson similarity values. Data from the fire treatment indicates that a simulated drought burn may …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2002), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. An overall summary of findings for the major VA Bay tributaries (i.e. James, York, and Rappahannock Rivers) is bulleted below while the remainder of this …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2002), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. An overall summary of findings for the major VA Bay tributaries (i.e. James, York and Rappahannock Rivers) is bulleted below while the remainder of this …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2002), Daniel M. Dauer, Harold G. Marshall, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Frederick A. Hoffman

Status and Trends for Virginia Chesapeake Bay

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded and some areas and indicators show continuing degradation. Progress in reducing nutrient inputs has made demonstrable improvements and we expect that continued progress toward nutrient reduction goals, along with appropriate fisheries management and chemical contaminant controls, will result in additional improvements to the Bay. An overall summary of findings for the major VA Bay tributaries (i.e. James, York, and Rappahannock Rivers) is bulleted below while the remainder of this …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2002), Daniel M. Dauer

Elizabeth River Reports

Executive Summary

A study of the macrobenthic communities of the Elizabeth River watershed was initiated in summer 1999. This report presents the data from the fourth year of sampling in 2002. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. ( 2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will …

Decision Process For Identification Of Estuarine Benthic Impairments, Roberto J. Llansó, Jon H. Volstad, Daniel M. Dauer

Benthic Applications

To meet the requirements of the Clean Water Act, the States of Maryland and Virginia are in the process of developing biological criteria for evaluating estuarine waters. The Chesapeake Bay Benthic Index of Biotic Integrity (B-IBI) is the basis for these biological criteria. As an initial step, a Workgroup developed an interim framework for the application of the B-IBI to the States’ water quality inventory report (305b report) and list of impaired waters (303d list). The Workgroup included representatives of the Maryland Department of the Environment (MDE), Maryland Department of Natural Resources (MDNR), Virginia Department of Environmental Quality (DEQ), USEPA …

Feeding Responses Of Juvenile And Adult Streblospio Benedicti Webster (Spionidae) To Organic Chemicals Bound To Glass Microbeads, Heidi Kathryn Mahon

Biological Sciences Theses & Dissertations

Spionid polychaetes feed at the sediment-water interface using a pair of ciliated palps. Polychaetes select food particles based upon characteristics including size, texture, specific gravity and organic coatings. Juvenile and adult spionids have different stable isotopic carbon signals, indicating the potential to differentiate organic cues ontogenetically. In the present study, the feeding responses of juvenile and adult Streblospio benedicti Webster to seven organic coatings bound (five amino acids and two carbohydrates) to glass microbeads were tested. Juveniles and adults were highly selective for all seven types of organically coated beads. Juveniles were highly selective for threonine; whereas adults were highly …

Male Reproductive Dynamics In The Caribbean Spiny Lobster Panulirus Argus, Jamie S. Heisig

Biological Sciences Theses & Dissertations

The population size structure of the Caribbean Spiny Lobster, Panulirus argus, in the Florida Keys, Florida (USA) has undergone a dramatic shift as a result of fishing pressure on the large individuals of the population. Male lobsters are affected most by fishing because of sexual dimorphism in size and other studies have shown that male size has direct impacts on reproductive output (i.e., number of fertilized eggs/clutch) that are independent of female size. To assess more precisely the impact of male size on fertilization success, I conducted laboratory experiments and field observations to examine various male reproductive attributes over …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: James River (1985-2001), Daniel M. Dauer, Harold G. Marshall, Kent E. Carpenter, John R. Donat, Michael F. Lane

Status and Trends for Virginia Chesapeake Bay

This summary includes materials provided by Rick Hoffman of the Chesapeake Bay Program of the Virginia Department of Environmental Quality. Environmental information regarding other important conditions in Chesapeake Bay (e.g. submerged aquatic vegetation, fisheries, chemical contaminants) has been reported previously (Chesapeake Bay and its Tributaries: Results of Monitoring Programs And Status of Resources; 2002 Biennial Report of the Secretary of Natural Resources to The Virginia General Assembly).

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: Rappahannock River (1985-2001), Daniel M. Dauer, Harold G. Marshall, Kent E. Carpenter, John R. Donat, Michael F. Lane

Status and Trends for Virginia Chesapeake Bay

This summary includes materials provided by Rick Hoffman of the Chesapeake Bay Program of the Virginia Department of Environmental Quality. Environmental information regarding other important conditions in Chesapeake Bay (e.g. submerged aquatic vegetation, fisheries, chemical contaminants) has been reported previously (Chesapeake Bay and its Tributaries: Results of Monitoring Programs And Status of Resources; 2002 Biennial Report of the Secretary of Natural Resources to The Virginia General Assembly).

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: York River (1985-2001), Daniel M. Dauer, Harold G. Marshall, Kent E. Carpenter, John R. Donat, Michael F. Lane

Status and Trends for Virginia Chesapeake Bay

This summary includes materials provided by Rick Hoffman of the Chesapeake Bay Program of the Virginia Department of Environmental Quality. Environmental information regarding other important conditions in Chesapeake Bay (e.g. submerged aquatic vegetation, fisheries, chemical contaminants) has been reported previously (Chesapeake Bay and its Tributaries: Results of Monitoring Programs And Status of Resources; 2002 Biennial Report of the Secretary of Natural Resources to The Virginia General Assembly).

The Virginia Chesapeake Bay and its tidal tributaries continue to show some environmental trends indicating progress toward restoration of a more balanced and healthy ecosystem. However, the Bay system remains degraded …

Extracellular Enzyme Activity And Uptake Of Carbon And Nitrogen Along An Estuarine Salinity And Nutrient Gradient, Margaret R. Mulholland, Cindy Lee, Patricia M. Gilbert

OES Faculty Publications

Amino acid oxidation (AAO) and peptide hydrolysis (PH) are processes affecting the recycling of organic material and nutrients. We compared extracellular AAO and PH rates to C and N uptake rates along estuarine gradients of salinity, nutrients and productivity in the Pocomoke River, a subestuary of the Chesapeake Bay. This estuary is seasonally depleted in inorganic N, and rich in dissolved organic material (DOM) throughout the year. AAO, PH, and N uptake rates measured in 1999 and 2000 were not limited to particular size fractions measured, or to auto- or heterotrophic groups of organisms. At a station near the turbidity …

Recruitment Variability Of Atlantic Croaker, Micropogonia Undulatus, With Observations On Environmental Factors, Sumalee Hoskin

Biological Sciences Theses & Dissertations

I examined entrance patterns of Atlantic croaker, Micropogonias undulatus by comparing the abundance, length, age and growth rates, of larvae as they entered Oregon and Ocracoke Inlets, NC. These biological factors were then compared against environmental factors to assess the influence the physical environment has on recruitment variability. Entrance abundance into Oregon Inlet was an order of magnitude higher than abundance into Ocracoke Inlet. However, the difference was influenced by three peak events in Oregon Inlet and non-parametric tests found no difference in median abundance between the two inlets. Mean standard length was smaller at Oregon Inlet than Ocracoke Inlet …

Benthic Biological Monitoring Program Of The Elizabeth River Watershed (2001) With A Study Of Paradise Creek, Daniel M. Dauer

Elizabeth River Reports

Executive Summary

A study of the macrobenthic communities of the Elizabeth River watershed was initiated in summer 1999. This report presents the data from the third year of sampling in 2001. The three objectives of the Benthic Biological Monitoring Program of the Elizabeth River watershed are: (1) To characterize the health of the tidal waters of the Elizabeth River watershed as indicated by the structure of the benthic communities. ( 2) To conduct trend analyses on long-term data at 14 fixed-point stations to relate temporal trends in the benthic communities to changes in water and/or sediment quality. Trend analyses will …

Fine Root Vitality And Its Application In A Minirhizotron Study Of A Co2 Enrichment In A Florida Scrub Oak Ecosystem, Brandon Todd Herbert

Biological Sciences Theses & Dissertations

Minirhizotron images are assigned color codes to approximate the age of individual roots in situ. Triphenyl-tetrazolium chloride (TTC) has been used to measure the vitality of plant tissue by detecting dehydrogenase activity. TTC was used to assess the vitality of root tissue by color in a scrub oak ecosystem at Kennedy Space Center in central Florida. Roots were excavated, sorted into four color classes and stained with TTC. The product of the reduction of TTC by dehydrogenase enzyme, formazan, was extracted and its absorbance recorded using a spectrophotometer. A significant difference (p2 enrichment being conducted on a scrub oak …

Long Term Residual Effects Of A Nutrient Addition On A Barrier Island Dune Ecosystem, Susan M. Heyel

Biological Sciences Theses & Dissertations

In 1991, 150 m² were fertilized with nitrogen on three dunes on Hog Island, part of the Virginia Coast Reserve Long Term Ecological Research site, to examine plant community response to nitrogen addition. In 2000, the fertilized plots continued to exhibit a positive growth response. This study sampled the aboveground biomass, belowground biomass, and nutrient content of the experimental plots to examine the long- term patterns of nitrogen retention in a nitrogen limited system. Aboveground and belowground biomass was significantly greater in the fertilized plots than in the control plots. Aboveground biomass exhibited was significantly greater in control and …

Development Of Diagnostic Approaches To Determine Sources Of Anthropogenic Stress Affecting Benthic Community Conditions In The Chesapeake Bay, Daniel M. Dauer, Michael F. Lane, Roberto J. Llansó

Benthic Applications

Benthic macrofauna are an important component of estuarine ecosystems. These organisms are a food source for higher trophic levels including fishes and crabs (Virnstein 1977, 1979; Holland et al. 1980; Dauer et al. 1982) and birds (Botton 1984; Quammen 1984). Benthic macrofauna affect both the physical and chemical properties of the sediment and the overlying water column (e.g., Rhoads and Young 1970; Rhoads 1973; Aller 1978, 1980), influence nutrient cycling (Rowe et al 1975; Zeiteschel 1980; Flint and Kamykowski 1984), and are capable of directly controlling phytoplankton biomass in the water column (Cleorn 1982; Officer et al 1982; Cohen et …

Summer Vertical Phytoplankton Distribution In The Lower Chesapeake Bay, Mollie Jill Weinstein

Biological Sciences Theses & Dissertations

Autotrophic picoplankton and phytoplankton composite samples were collected from the surface, pycnocline, and bottom water layers at three stations in the lower Chesapeake Bay between June and September 1993. Using light microscopy a total of 170 phytoplankton taxa were identified. Utilizing epifluorescent microscopy, the picoplankton taxa were distinguished by size, representing species with cells less than 2 microns. Diatoms were the dominant taxa during this period, with lesser representation by the other phytoplankton components. Within the picoplankton category, cyanobacteria were dominant. Statistical analyses of the data indicated the vertical composition and abundance of the phytoplankton was not significantly different over …

Status And Trends In Water Quality And Living Resources In The Virginia Chesapeake Bay: 1985- 2000, Daniel M. Dauer, Michael F. Lane, Harold G. Marshall, Kent E. Carpenter, John R. Donat

Status and Trends for Virginia Chesapeake Bay

A detailed overview of the Chesapeake Bay's living resources, water quality, and its major Virginia tributaries.