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Full-Text Articles in Physical Sciences and Mathematics

Evaluation Of Striped Bass Stocks In Virginia, Monitoring And Tagging Studies, 2004-2008 Annual Report, 1 September 2007 - 31 September 2008, Philip W. Sadler, John M. Hoenig, Robert E. Harris, Matthew W. Smith, Rebecca J. Wilk, Lydia M. Goins Nov 2008

Evaluation Of Striped Bass Stocks In Virginia, Monitoring And Tagging Studies, 2004-2008 Annual Report, 1 September 2007 - 31 September 2008, Philip W. Sadler, John M. Hoenig, Robert E. Harris, Matthew W. Smith, Rebecca J. Wilk, Lydia M. Goins

Reports

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 September 2007 through 31 August 2008. It includes an assessment of the biological characteristics of striped bass taken from the 2008 spring spawning run, estimates of annual survival and fishing mortality based on annual spring tagging, and the results of the study that documents the prevalence of mycobacterial infections of striped bass in Chesapeake Bay. The information contained in this report is required by the Atlantic States Marine Fisheries Commission and is used to implement a coordinated management plan for …


Evaluating Recruitment Of American Eel, Anguilla Rostrata, To The Potomac River (Spring 2008), Mary C. Fabrizio, Troy D. Tuckey Sep 2008

Evaluating Recruitment Of American Eel, Anguilla Rostrata, To The Potomac River (Spring 2008), Mary C. Fabrizio, Troy D. Tuckey

Reports

The Atlantic States Marine Fisheries Commission (ASMFC) adopted the Interstate Fishery Management Plan (FMP) for the American eel in November 1999. The FMP focuses on increasing coastal states’ efforts to collect American eel data through both fishery-dependent and fishery-independent studies. Consequently, member jurisdictions agreed to implement an annual survey for young of the year (YOY) American eels. The survey is intended to “…characterize trends in annual recruitment of the YOY eels over time [to produce a] qualitative appraisal of the annual recruitment of American eel to the U.S. Atlantic Coast” (ASMFC, 2000). The development of these surveys began in 2000 …


Oscillation Regularity In Noise-Driven Excitable Systems With Multi-Time-Scale Adaptation, William H. Nesse, Christopher A. Del Negro, Paul C. Bressloff Aug 2008

Oscillation Regularity In Noise-Driven Excitable Systems With Multi-Time-Scale Adaptation, William H. Nesse, Christopher A. Del Negro, Paul C. Bressloff

Arts & Sciences Articles

We investigate oscillation regularity of a noise-driven system modeled with a slow after-hyperpolarizing adaptation current (AHP) composed of multiple-exponential relaxation time scales. Sufficiently separated slow and fast AHP time scales (biphasic decay) cause a peak in oscillation irregularity for intermediate input currents I, with relatively regular oscillations for small and large currents. An analytic formulation of the system as a stochastic escape problem establishes that the phenomena is distinct from standard forms of coherence resonance. Our results explain data on the oscillation regularity of the pre-Bötzinger complex, a neural oscillator responsible for inspiratory breathing rhythm generation in mammals.


Estimating Relative Abundance Of Young Of Year American Eel, Anguilla Rostrata, In The Virginia Tributaries Of Chesapeake Bay (Spring 2007), Troy D. Tuckey Jul 2008

Estimating Relative Abundance Of Young Of Year American Eel, Anguilla Rostrata, In The Virginia Tributaries Of Chesapeake Bay (Spring 2007), Troy D. Tuckey

Reports

The Atlantic States Marine Fisheries Commission (ASMFC) adopted the Interstate Fishery Management Plan (FMP) for the American eel in November 1999. The FMP focuses on increasing coastal states’ efforts to collect American eel data through both fishery dependent and fishery independent studies. Consequently, member jurisdictions (including Virginia) agreed to implement an annual survey for YOY American eels. The survey is intended to “…characterize trends in annual recruitment of the YOY eels over time [to produce a] qualitative appraisal of the annual recruitment of American eel to the U.S. Atlantic Coast” (ASMFC, 2000). The development of these surveys began in 2000 …


Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2007 Virginia Shellfish Aquaculture Crop Reporting Survey, Thomas J. Murray, Michael J. Oesterling May 2008

Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2007 Virginia Shellfish Aquaculture Crop Reporting Survey, Thomas J. Murray, Michael J. Oesterling

Reports

Continued growth of the shellfish aquaculture industry in Virginia has added significant value to the state’s seafood marketplace. Today, watermen continue to harvest both hard clams and oysters from the state’s public resources, albeit at diminished rates. At the same time, Virginia’s watermen-farmers are providing growing quantities of additional quality shellfish to consumers. Following the lead of the hard clam industry, there has been a significant transition to intensive aquaculture of native oysters in recent years. The once extensive oyster planting has disappeared primarily as a result of endemic oyster diseases and increasing wildlife predation of seed oysters. In its …


Monitoring Relative Abundance Of American Shad In Virginia Rivers 2007 Annual Report, John E. Olney, Brian Watkins Apr 2008

Monitoring Relative Abundance Of American Shad In Virginia Rivers 2007 Annual Report, John E. Olney, Brian Watkins

Reports

Concern about the decline in landings of American shad (Alosa sapidissima) along the Atlantic coast prompted the development of an interstate fisheries management plan (FMP) under the auspices of the Atlantic States Marine Fisheries Management Program (ASMFC 1999). Legislation enables imposition of federal sanctions on fishing in those states that fail to comply with the FMP. To be in compliance, coastal states are required to implement and maintain fishery-dependent and fishery-independent monitoring programs as specified by the FMP. For Virginia, these requirements include spawning stock assessments, the collection of biological data on the spawning run (e.g., age-structure, sex ratio, and …


Six Fish And 600,000 Thirsty Folks—A Fishing Moratorium On American Shad Thwarts A Controversial Municipal Reservoir Project In Virginia, Usa, J. E. Olney, Donna M. Bilkovic, Carl Hershner, Lyle M. Varnell, Harry V. Wang, Roger L. Mann Jan 2008

Six Fish And 600,000 Thirsty Folks—A Fishing Moratorium On American Shad Thwarts A Controversial Municipal Reservoir Project In Virginia, Usa, J. E. Olney, Donna M. Bilkovic, Carl Hershner, Lyle M. Varnell, Harry V. Wang, Roger L. Mann

VIMS Books and Book Chapters

Moratoria on fishing directly impact fishers, distributors and marketers of product and can have serious socio-economic implications. Moratoria can impact communities but usually populations closely linked to the banned activity. In an unprecedented example, a moratorium on fishing in Virginia has directly impacted a nonfishing citizenry by thwarting plans for a public utility. In May 2003, a panel empowered to regulate marine resources denied permission to withdraw raw water from a pristine freshwater river, the Mattaponi. The controversial action spoiled a multi-million dollar plan to establish the King William Reservoir, a water source considered essential to future growth and development …


A Molecular Analysis Of Atlantic Menhaden (Brevoortia Tyrannus) Stock Structure, Abigail J. Lynch Jan 2008

A Molecular Analysis Of Atlantic Menhaden (Brevoortia Tyrannus) Stock Structure, Abigail J. Lynch

Dissertations, Theses, and Masters Projects

Atlantic menhaden is an ecologically and economically important species along the U.S. east coast. As a filter-feeder and key prey fish, it provides a critical link between primary production, phytoplankton, and larger piscivorous predators, such as striped bass, bluefish, and weakfish. The species is also the target of one of the largest commercial fisheries in the country. Menhaden are assessed as a single, coastwide stock, and recent assessments indicate that it is not overfished. However, there is very limited population genetics data to support the assumption of a single stock. Additionally, the recent consolidation of the fishery and localization of …


Natural Mortality Of Blue Crab: Estimation And Influence On Population Dynamics, David A. Hewitt Jan 2008

Natural Mortality Of Blue Crab: Estimation And Influence On Population Dynamics, David A. Hewitt

Dissertations, Theses, and Masters Projects

The blue crab Callinectes sapidus supports one of the most important fisheries in the Chesapeake Bay and is the leading contributor to blue crab landings in the United States. Assessment and management of blue crab stocks has been hampered by a lack of estimates of natural mortality rates, a key parameter in assessment models. In Chapter 2, we demonstrate that the approach used for estimating natural mortality that had been used in past assessments was flawed, and provide justification for a superior alternative. In Chapter 3, we synthesize our current understanding of natural mortality rates in adult blue crab and …


Effects Of Urban Development On Breeding Bird Diversity: The Role Of Diet And Migration, Elise Anne Larsen Jan 2008

Effects Of Urban Development On Breeding Bird Diversity: The Role Of Diet And Migration, Elise Anne Larsen

Dissertations, Theses, and Masters Projects

No abstract provided.


Age, Growth, And Demography Of The Sandbar Shark, Carcharhinus Plumbeus, Over Temporal And Spatial Scales, Jason G. Romine Jan 2008

Age, Growth, And Demography Of The Sandbar Shark, Carcharhinus Plumbeus, Over Temporal And Spatial Scales, Jason G. Romine

Dissertations, Theses, and Masters Projects

Numbers of sandbar sharks, Carcharhinus plumbeus, in the Northwest Atlantic have experienced drastic declines since the early 1980's reaching their minima during the early 1990's. Catch rates in the early 1990's were a mere 25% of those during the 1980's. Such drastic reductions in other fish stocks have often caused compensatory responses, most notably the cod stocks in the Northwest Atlantic. Compensatory responses in depressed populations may include decreased natural mortality, increased fecundity, or increased growth rates. Compensation for population fluctuations below carrying capacities have been recognized for many terrestrial and oceanic r-selected organisms, but few instances have been noted …


Bottom-Up And Top-Down Controls On Sedimentary Ecosystem Functioning In A Seagrass Habitat, Amanda C. Spivak Jan 2008

Bottom-Up And Top-Down Controls On Sedimentary Ecosystem Functioning In A Seagrass Habitat, Amanda C. Spivak

Dissertations, Theses, and Masters Projects

Coastal seagrass ecosystems are complex habitats that are increasingly influenced by human perturbations. Disturbances that affect the strength of bottom-up (i.e. resource availability) and top-down (i.e. consumer) controls may also influence biomass distribution between trophic levels, sediment biogeochemistry, and seagrass ecosystem metabolism. Here, I experimentally tested how top-down and bottom-up perturbations interact with community structure (diversity, food chain length of epibenthic consumers) to alter sediment biogeochemistry and ecosystem metabolism in an experimental eelgrass (Zostera marina ) system. My data indicated that resource availability influenced SOM composition and ecosystem metabolism. Light availability tended to be a stronger determinant of SOM composition …


Mesopelagic Zooplankton Feeding Ecology And Effects On Particle Repackaging And Carbon Transport In The Subtropical And Subarctic North Pacific Ocean, Stephanie E. Wilson Jan 2008

Mesopelagic Zooplankton Feeding Ecology And Effects On Particle Repackaging And Carbon Transport In The Subtropical And Subarctic North Pacific Ocean, Stephanie E. Wilson

Dissertations, Theses, and Masters Projects

Differences in zooplankton community structure and diet within the mesopelagic zone (base of euphotic zone to 1000 m) play a key role in affecting the efficiency by which organic matter is exported to depth, but how the structure of mesopelagic food webs change with depth or location is poorly known. I examined how mesopelagic zooplankton affect particle export in an oligotrophic (Hawaii Ocean Time-series site ALOHA) compared to a mesotrophic (Japanese time series site K2) open-ocean system. In the first part of the study, I investigated how fecal pellet characteristics change with depth in order to quantify the extent of …


Novel Use Of A Natural Isotope Signature To Track Recruitment And Evaluate Age Determination Methods For The 2002 Year Class Of American Shad In The York River, Sally A. Upton Jan 2008

Novel Use Of A Natural Isotope Signature To Track Recruitment And Evaluate Age Determination Methods For The 2002 Year Class Of American Shad In The York River, Sally A. Upton

Dissertations, Theses, and Masters Projects

No abstract provided.


Virginia Game Fish Tagging Program Annual Report 2007, John A. Lucy, Lewis Gillingham Jan 2008

Virginia Game Fish Tagging Program Annual Report 2007, John A. Lucy, Lewis Gillingham

Reports

Initiated in 1995, the Virginia Game Fish Tagging Program (VGFTP) database is comprised of tagged fish records, and corresponding recaptured fish records. These records are primarily generated through contributed efforts of a dedicated corps of trained marine anglers targeting only a select number of target species. The recaptured fish records are the result of observant individuals noticing the tags in live or freshly-boxed/shipped fish. Recapture reports originate from a mix of sources, including marine anglers, commercial fishers, workers in fish packinghouses, wholesale and retail sellers of fish, and NOAA Fisheries observers on coastal trawl boats.


International Trade In Seafood And Related Products: An Assessment Of U.S. Trade Patterns, James E. Kirkley, John M. Ward, Christopher M. Moore, Christopher Hayes, Brian Hooker, John Walden Jan 2008

International Trade In Seafood And Related Products: An Assessment Of U.S. Trade Patterns, James E. Kirkley, John M. Ward, Christopher M. Moore, Christopher Hayes, Brian Hooker, John Walden

Reports

No abstract provided.


Interspecific Interactions In Oyster Reef Communities: The Effect Of Established Fauna On Oyster Larval Recruitment, Brian B. Barnes Jan 2008

Interspecific Interactions In Oyster Reef Communities: The Effect Of Established Fauna On Oyster Larval Recruitment, Brian B. Barnes

Dissertations, Theses, and Masters Projects

The behaviors of oyster larvae are difficult to monitor or experimentally manipulate, especially in field conditions. As a result, little is known of the fate of oysters in the larval portion of their life cycle, prior to recruitment. At the transition from pelagic larvae to benthic adults, larvae are likely to come into contact with many invertebrates resident on oyster reefs. Of these, fouling epifauna are generally believed to reduce the settlement of interspecific larvae through competitive exclusion and predation. Studies of these interactions, however, often utilize artificial settlement panels, which can exhibit different recruitment patterns to those observed on …


Effects Of Shoreline Development And Oyster Reefs On Benthic Communities In Lynnhaven, Virginia, Amanda Sue Lawless Jan 2008

Effects Of Shoreline Development And Oyster Reefs On Benthic Communities In Lynnhaven, Virginia, Amanda Sue Lawless

Dissertations, Theses, and Masters Projects

Shoreline hardening and construction of restoration oyster reefs are occurring at rapid rates throughout Chesapeake Bay and little research has been conducted to determine whether installment of a hardened shoreline and oyster reef placement has an effect on the surrounding benthic infaunal communities. I investigated the effects of shoreline development and oyster reefs on benthic communities in Lynnhaven, Virginia. Throughout Lynnhaven, I determined the effects of shoreline type (natural marsh, oyster reef, rip-rap and bulkhead), sediment grain size, Total Organic Carbon/Total Nitrogen (TOC/TN) of the sediment, and predation (caging study) on density, biomass, and diversity of benthic infauna. An information-theoretic …


Zooplankton Community Structure In A Cyclonic And Mode-Water Eddy In The Sargasso Sea, Bethany Rose Eden Jan 2008

Zooplankton Community Structure In A Cyclonic And Mode-Water Eddy In The Sargasso Sea, Bethany Rose Eden

Dissertations, Theses, and Masters Projects

Recent evidence suggests that mesoscale eddies are an important mechanism for supplying nutrients to the surface waters of oligotrophic gyres. However, little is known about the biological response to these physical perturbations. Because mesozooplankton play a key role in food-web interactions and the flux of carbon and other elements from surface waters, changes in mesozooplankton community structure can affect biogeochemical cycling. During the summers of 2004 and 2005, respectively, we followed the development of a cyclonic eddy and an anti-cyclonic mode-water eddy in the Sargasso Sea. Zooplankton tows were conducted across both eddies using a Multiple Opening and Closing Net …


An Evaluation Of Norovirus Persistence In Estuarine Water And Of Methods For Its Detection In Treated Sewage Effluent, Margaret H. Fagan Jan 2008

An Evaluation Of Norovirus Persistence In Estuarine Water And Of Methods For Its Detection In Treated Sewage Effluent, Margaret H. Fagan

Dissertations, Theses, and Masters Projects

No abstract provided.


Status, Distribution And Reproductive Rates Of American Oystercatchers In Virginia, Alexandra Lee Wilke Jan 2008

Status, Distribution And Reproductive Rates Of American Oystercatchers In Virginia, Alexandra Lee Wilke

Dissertations, Theses, and Masters Projects

No abstract provided.


Mercury Levels In Newly Independent Songbirds, Anne Moire Condon Jan 2008

Mercury Levels In Newly Independent Songbirds, Anne Moire Condon

Dissertations, Theses, and Masters Projects

No abstract provided.


Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass Jan 2008

Community Dynamics In Submersed Aquatic Vegetation: Intermediate Consumers As Mediators Of Environmental Change, James G. Douglass

Dissertations, Theses, and Masters Projects

Natural ecosystems are strongly affected by changes in resource supply (bottom-up forces) and by changes in upper trophic levels (top-down forces). The extent to which these processes impact a system depends largely on the responses of organisms at middle trophic levels. In seagrass beds, a group of mid-level consumers known as mesograzers form a critical link in the chain of impact, connecting seagrass and epiphytic algae with predatory fishes and crustaceans. I observed dramatic seasonal and interannual changes in mesograzer abundance and species composition in eelgrass (Zostera marina) beds of lower Chesapeake Bay, Virginia, and endeavored to explain the top-down …