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Full-Text Articles in Life Sciences

Evaluation Of Striped Bass Stocks In Virginia: Monitoring And Tagging Studies, 2015-2019 Progress Report 1 September 2016 - 31 November 2017, Philip W. Sadler, Lydia M. Goins, John M. Hoenig, Savannah Michaelsen, Maya L. Groner, Robert E. Harris Nov 2017

Evaluation Of Striped Bass Stocks In Virginia: Monitoring And Tagging Studies, 2015-2019 Progress Report 1 September 2016 - 31 November 2017, Philip W. Sadler, Lydia M. Goins, John M. Hoenig, Savannah Michaelsen, Maya L. Groner, Robert E. Harris

Reports

This report presents the results of striped bass (Morone saxatilis) tagging and monitoring activities in Virginia during the period 1 September 2016 through 31 August 2017. It includes an assessment of the biological characteristics of striped bass taken from the 2017 spring spawning run and estimates of annual survival and fishing mortality based on annual spring tagging. Also included is an investigation on the potential use of close-kin analyses to determine the size of the spawning stock in the Rappahannock River and an evaluation of mortality rates associated with the bacterial dermal disease mycobacteriosis in relation to water …


Performance Of A Low-Cost, Solar-Powered Pop-Up Satellite Archival Tag For Assessing Post-Release Mortality Of Atlantic Bluefin Tuna (Thunnus Thynnus) Caught In The Us East Coast Light-Tackle Recreational Fishery, William M. Goldsmith, Andrew M. Scheld, John Graves Nov 2017

Performance Of A Low-Cost, Solar-Powered Pop-Up Satellite Archival Tag For Assessing Post-Release Mortality Of Atlantic Bluefin Tuna (Thunnus Thynnus) Caught In The Us East Coast Light-Tackle Recreational Fishery, William M. Goldsmith, Andrew M. Scheld, John Graves

VIMS Articles

Pop-up satellite archival tags (PSATs) are a valuable tool for estimating mortality of pelagic fishes released from commercial and recreational fishing gears. However, the high cost of PSATs limits sample sizes, resulting in low-precision post-release mortality estimates with little management applicability. We evaluate the performance of a lower-cost PSAT designed to enable large-scale post-release mortality studies. The tag uses solar rather than battery power, does not include a depth sensor, and transmits daily summaries of light and temperature data rather than high-resolution habitat profiles, contributing to a substantially lower per-unit price. We assessed the tag’s ability to detect mortality while …


Reef Height Drives Threshold Dynamics Of Restored Oyster Reefs, Allison M. Colden, Robert J. Latour, Rom Lipcius Nov 2017

Reef Height Drives Threshold Dynamics Of Restored Oyster Reefs, Allison M. Colden, Robert J. Latour, Rom Lipcius

VIMS Articles

Nonlinear threshold responses to biotic or abiotic forcing may produce multiple population trajectories dependent upon initial conditions, which can reinforce population recovery or drive local ex - tinction, yet experimental tests of this phenomenon are lacking in marine ecosystems. In field experiments at 4 sites in 2 tributaries of lower Chesapeake Bay, we examined demographic responses (density and survival) of eastern oyster Crassostrea virginica populations to reef height and associated gradients in sediment deposition and habitat complexity. After 2 yr, oyster reefs exhibited diverging trajectories to ward either degradation or persistence, dependent upon initial reef height. Reefs higher than 0.3 …


A Brief Guide To Striped Bass Ecology & Management In Chesapeake Bay, Mary C. Fabrizio, Troy D. Tuckey, Susanna Musick Nov 2017

A Brief Guide To Striped Bass Ecology & Management In Chesapeake Bay, Mary C. Fabrizio, Troy D. Tuckey, Susanna Musick

Reports

Chesapeake Bay striped bass support important recreational fisheries along the US Atlantic coast; in the late 1970s, the population of striped bass collapsed as a result of overfishing and poor water quality in rivers used for spawning and rear-ing of young. Informed by stock assessments, strict management regulations were enacted in the mid-1980s and early 1990s; these highly effective regulations resulted in the recovery of the population in 1995. A key to the successful recov-ery of the Atlantic coast striped bass was the wide range of ages of spawning females and the associated differences in spawning behavior among ages. Age …


Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard Oct 2017

Bottom-Up Control Of Parasites, David S. Johnson, Richard Heard

VIMS Articles

Parasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free-living organisms. Bottom-up theory predicts that resource enhancement will increase the abundance and biomass of free-living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape-level experiment in which salt marshes (60,000 m2 each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod, Orchestia grillus, and the density and biomass of its …


Results For The 2017 Vims Industry Cooperative Surveys Of The Mid-Atlantic, Nantucket Lightship Closed Area, And Closed Area Ii Resource Areas, David Rudders, Sally Roman, Hunter Tipton, Jennifer Anders Oct 2017

Results For The 2017 Vims Industry Cooperative Surveys Of The Mid-Atlantic, Nantucket Lightship Closed Area, And Closed Area Ii Resource Areas, David Rudders, Sally Roman, Hunter Tipton, Jennifer Anders

Reports

The Virginia Institute of Marine Science (VIMS) conducted high resolution sea scallop dredge surveys of the entire Mid-Atlantic (MAB) sea scallop resource area, the Nantucket Lightship (NLCA) access area and surrounds, and the CA II access area and Extension Closure during May-July of 2017 (Figure 1). These surveys were funded by the Sea Scallop Research Set-Aside Program (RSA). Exploitable biomass for each survey is shown in Table 1 for each spatially explicit SAMS (Scallop Area Management Simulator) model area (Figure 2-4). SAMS areas account for differences in recruitment, vital rates, and fishing effort. At the time of the surveys, exploitable …


Exposure Of Bald Eagle Nestlings To Contaminants On National Park Service Lands Within The Chesapeake Bay, Interim Report: Fall 2017, B. D. Watts, B. J. Paxton, M. L. Pitts Oct 2017

Exposure Of Bald Eagle Nestlings To Contaminants On National Park Service Lands Within The Chesapeake Bay, Interim Report: Fall 2017, B. D. Watts, B. J. Paxton, M. L. Pitts

CCB Technical Reports

No abstract provided.


Impact Of Disease On The Survival Of Three Commercially Fished Species, John M. Hoenig, Maya L. Groner, Matthew W. Smith, Wolfgang K. Vogelbein, David M. Taylor, Donald F. Landers, John T. Swenarton, David T. Gauthier, Philip W. Sadler, Mark A. Matsche, Ashley N. Haines, Hamish J. Small, Roger Pradel, Remi Choquet, Jeffrey D. Shields Oct 2017

Impact Of Disease On The Survival Of Three Commercially Fished Species, John M. Hoenig, Maya L. Groner, Matthew W. Smith, Wolfgang K. Vogelbein, David M. Taylor, Donald F. Landers, John T. Swenarton, David T. Gauthier, Philip W. Sadler, Mark A. Matsche, Ashley N. Haines, Hamish J. Small, Roger Pradel, Remi Choquet, Jeffrey D. Shields

VIMS Articles

Recent increases in emergent infectious diseases have raised concerns about the sustainability of some marine species. The complexity and expense of studying diseases in marine systems often dictate that conservation and management decisions are made without quantitative data on population-level impacts of disease. Mark-recapture is a powerful, underutilized, tool for calculating impacts of disease on population size and structure, even in the absence of etiological information. We applied logistic regression models to mark-recapture data to obtain estimates of disease-associated mortality rates in three commercially important marine species: snow crab (Chionoecetes opilio) in Newfoundland, Canada, that experience sporadic epizootics of bitter …


Community Interactions And Density Dependence In The Southeast United States Coastal Shark Complex, Cassidy D. Peterson, Kristene D. Parsons, Dana M. Bethea, William B. Driggers Iii, Robert J. Latour Sep 2017

Community Interactions And Density Dependence In The Southeast United States Coastal Shark Complex, Cassidy D. Peterson, Kristene D. Parsons, Dana M. Bethea, William B. Driggers Iii, Robert J. Latour

VIMS Articles

Studies aiming to assess intra- and interspecies community relationships in marine habitats are typically limited to accessible, nearshore areas of restricted temporal and spatial scale, within which only segments of the populations of interest are available. Using multivariate first-order auto regressive state-space (MARSS-1) models, we estimated measures of interspecies interactions and density dependence of 7 Atlantic coastal shark species (4 large and 3 small coastal sharks) at 2 spatial scales. Localized analyses were based on data from 4 relatively spatially limited, fishery-independent surveys conducted along the southeast US Atlantic coast and within the Gulf of Mexico. We then compared these …


Spatiotemporal Trends And Drivers Of Fish Condition In Chesapeake Bay, Robert J. Latour, James Gartland, Christopher F. Bonzek Sep 2017

Spatiotemporal Trends And Drivers Of Fish Condition In Chesapeake Bay, Robert J. Latour, James Gartland, Christopher F. Bonzek

VIMS Articles

Measures of condition in fishes are often used to assess the general well-being of fish populations since condition reflects the biotic and abiotic factors experienced by individuals over moderate time scales. Fish condition can also be used as an indicator of ecosystem suitability in the context of ecosystem-based management. From an ecosystem perspective, evaluation of fish condition is best described over multiple spatiotemporal scales and in a multi-species context. This study analyzed 14 yr (2002-2015) of fisheries-independent trawl survey data to evaluate trends in condition for 16 demersal fishes inhabiting Chesapeake Bay, the largest estuary in the USA. Seasonal and …


Sea Level Rise May Increase Extinction Risk Of A Saltmarsh Ontogenetic Habitat Specialist, David S. Johnson, Bethany L. Williams Aug 2017

Sea Level Rise May Increase Extinction Risk Of A Saltmarsh Ontogenetic Habitat Specialist, David S. Johnson, Bethany L. Williams

VIMS Articles

Specialist species are more vulnerable to environmental change than generalist species. For species with ontogenetic niche shifts, specialization may occur at a particular life stage making those stages more susceptible to environmental change. In the salt marshes in the northeast U.S., accelerated sea level rise is shifting vegetation patterns from flood-intolerant species such as Spartina patens to the flood-tolerant Spartina alterniflora. We tested the potential impact of this change on the coffee bean snail, Melampus bidentatus, a numerically dominant benthic invertebrate with an ontogenetic niche shift. From a survey of eight marshes throughout the northeast U.S., small snails …


Mapping Bald Eagle Activity Shadows Around Communal Roosts, B. D. Watts, Courtney Turrin Jul 2017

Mapping Bald Eagle Activity Shadows Around Communal Roosts, B. D. Watts, Courtney Turrin

Arts & Sciences Articles

We assessed diurnal activity patterns associated with communal roosts (n = 26) by tracking nonbreeding bald eagles (Haliaeetus leucocephalus; n = 58) within the upper Chesapeake Bay, USA, 2008-2013. We used daytime locations (n = 54,165) to map activity shadows (using home range analytics, 90% kernel) around communal roosts, to evaluate the spatial structure and to delineate diurnal activity centers. We overlaid a range (100-3,200 m) of buffers around the perimeter of each roost to estimate the benefits of management scenarios in extending protection to daytime activities. Activity shadows around roosts varied from 1.5 km(2) to 116 km(2) ((x) over …


Development And Implementation Of A High Precision Resource Wide Dredge Survey Of The Mid-Atlantic Scallop Resource Are: Final Report, David Rudders, Sally Roman Jun 2017

Development And Implementation Of A High Precision Resource Wide Dredge Survey Of The Mid-Atlantic Scallop Resource Are: Final Report, David Rudders, Sally Roman

Reports

The sea scallop fishery is currently the most valuable single species fishery in the United States. Part of this success stems from a hybrid management strategy that incorporates a spatial component (rotational closed areas) with traditional fishery management approaches. While much recent attention has focused on the success of closed areas (e.g. Elephant Trunk Closed Area), production from open areas had enabled scallop landings to remain high and relatively stable over the past few years. Regardless of the management approach, timely and accurate information related to scallop distribution and biomass is critical for the effective management of the resource. This …


Discard Mortality Of Sea Scallops Following Capture And Handling In The Sea Scallop Dredge Fishery - Final Report, David Rudders, Sally Roman, James A. Sulikowski, John A. Mandlem, Ryan J. Knotek May 2017

Discard Mortality Of Sea Scallops Following Capture And Handling In The Sea Scallop Dredge Fishery - Final Report, David Rudders, Sally Roman, James A. Sulikowski, John A. Mandlem, Ryan J. Knotek

Reports

The focus of sea scallop, Placopecten magellanicus, management over the past 20 years has been to encourage the harvest of larger animals. This has been accomplished through a series of management measures including gear modifications, effort controls, crew size limitations and spatial management to protect juvenile scallops. While these measures have been effective in reducing the harvest of small scallops, their capture does still occur. Central to fully understanding the impact of the fishery on the resource, is a comprehensive estimate of the non-harvest mortality associated with commercial operations. Non-harvest mortality can be broken down into a number of different …


History Of The Virginia Oyster Fishery, Chesapeake Bay, Usa, David M. Schulte May 2017

History Of The Virginia Oyster Fishery, Chesapeake Bay, Usa, David M. Schulte

VIMS Articles

Oyster populations in Virginia's waters of Chesapeake Bay were lightly exploited until the early 1800s, when industrial fishery vessels first arrived, driven south from New England due to the collapse of northeastern oyster fisheries. Early signs of overexploitation and habitat degradation were evident by the 1850s. The public fishery, where oyster fishers harvest on state-owned bottom, rapidly developed after the Civil War and peaked in the early 1880s. Declines were noted by the late 1880s and eventually prompted the creation of Virginia's shell-planting and oyster-seed (young-of-the-year, YOY) moving repletion program in the 1920s. Despite management and increasing repletion efforts, the …


Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay: Annual Progress Report 2016-2017, Brian K. Gallagher, Mary C. Fabrizio, Troy D. Tuckey May 2017

Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay: Annual Progress Report 2016-2017, Brian K. Gallagher, Mary C. Fabrizio, Troy D. Tuckey

Reports

The 2016 Striped Bass juvenile abundance index was 5.15 and was not significantly different from the reference mean of 7.77 observed in 1980-2009. Abundance indices in the James, York and Rappahannock rivers in 2016 were not significantly different than their historic averages (1967-2015). Juvenile White Perch abundance indices in 2016 were near historic averages in the York and Rappahannock rivers, but below the historic average in the James River. Because a new seine net was used during the 2016 survey, catches of Striped Bass and White Perch were adjusted using preliminary calibration factors derived from paired hauls of the old …


Virginia Game Fish Tagging Program Annual Report 2016, Susanna Musick, Lewis Gillingham May 2017

Virginia Game Fish Tagging Program Annual Report 2016, Susanna Musick, Lewis Gillingham

Reports

Through 2016, the Virginia Game Fish Tagging Program (VGFTP) has maintained a 21-year database of records for tagged and recaptured fish. The program is a cooperative project of the Virginia Saltwater Fishing Tournament (VSFT) under the Virginia Marine Resources Commission-(VMRC) and the Virginia Institute of Marine Science (VIMS) of the College of William and Mary (under the VIMS Marine Advisory Program).


Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2016 Virginia Shellfish Aquaculture Crop Reporting Survey, Karen Hudson May 2017

Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2016 Virginia Shellfish Aquaculture Crop Reporting Survey, Karen Hudson

Reports

The hatchery-based shellfish aquaculture industry in Virginia continues to grow adding significant value to the Commonwealth's seafood marketplace. Today, watermen harvest both hard clams and oysters from the Commonwealth's public resources,albeit at rates diminished from historic levels. At the same time, Virginia's watermen-farmers, utilizing production from a land-based hatchery, are providing additional quantities of quality shellfish to consumers.

This survey, in its 11th year, is intended to continue annual assessments with which to gauge growth and inputs in Virginia's hatchery-based shellfish aquaculture industry. This report is based upon an industry survey completed during the first quarter of 2017.

While these …


Annual Report - 2016 Data Collection And Analysis In Support Of Single And Multispecies Stock Assessments In Chesapeake Bay: The Chesapeake Bay Multispecies Monitoring And Assessment Program, Christopher F. Bonzek, James Gartland, Debra J. Gauthier, Robert J. Latour May 2017

Annual Report - 2016 Data Collection And Analysis In Support Of Single And Multispecies Stock Assessments In Chesapeake Bay: The Chesapeake Bay Multispecies Monitoring And Assessment Program, Christopher F. Bonzek, James Gartland, Debra J. Gauthier, Robert J. Latour

Reports

Historically, fisheries management has been based on the results of single‐species stock assessment models that focus on the interplay between exploitation level and sustainability. There currently exists a suite of standard and accepted analytical frameworks (e.g., virtual population analysis (VPA), biomass dynamic production modeling, delay difference models, etc.) for assessing the stocks, projecting future stock size, evaluating recovery schedules and rebuilding strategies for overfished stocks, setting allowable catches, and estimating fishing mortality or exploitation rates. A variety of methods also exist to integrate the biological system and the fisheries resource system, thereby enabling the evaluation of alternative management strategies on …


Northeast Area Monitoring And Assessment Program (Neamap) 2016 Data Collection And Analysis In Support Of Single And Multispecies Stock Assessments In The Mid‐Atlantic: Northeast Area Monitoring And Assessment Program Near Shore Trawl Survey, Christopher F. Bonzek, James Gartland, Debra J. Gauthier, Robert J. Latour May 2017

Northeast Area Monitoring And Assessment Program (Neamap) 2016 Data Collection And Analysis In Support Of Single And Multispecies Stock Assessments In The Mid‐Atlantic: Northeast Area Monitoring And Assessment Program Near Shore Trawl Survey, Christopher F. Bonzek, James Gartland, Debra J. Gauthier, Robert J. Latour

Reports

Concerns regarding the status of fishery‐independent data collection from continental shelf waters between Cape Hatteras, North Carolina and the U.S. / Canadian border led the Atlantic States Marine Fisheries Commission’s (ASMFC) Management and Science Committee (MSC) to draft a resolution in 1997 calling for the formation of the Northeast Area Monitoring and Assessment Program (NEAMAP) (ASMFC 2002). NEAMAP is a cooperative state‐federal program modeled after the Southeast Area Monitoring and Assessment Program (SEAMAP), which has been coordinating fishery‐independent data collection south of Cape Hatteras since the mid‐ 1980s (Rester 2001). The four main goals of this new program directly address …


Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2016 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee Apr 2017

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2016 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the nineteenth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2016, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on a new fishery-independent monitoring program using staked gillnets to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis) in the Rappahannock River. Data are also reported from two separate fishery-independent monitoring …


Estimating Relative Abundance Of Young-Of-The-Year American Eel, Anguilla Rostrata, In The Virginia Tributaries Of Chesapeake Bay, Spring 2016, Mary C. Fabrizio, Troy D. Tuckey Mar 2017

Estimating Relative Abundance Of Young-Of-The-Year American Eel, Anguilla Rostrata, In The Virginia Tributaries Of Chesapeake Bay, Spring 2016, Mary C. Fabrizio, Troy D. Tuckey

Reports

American Eel (Anguilla rostrata) is a valuable commercial species along the Atlantic coast of North America from New Brunswick to Florida. In the U.S., harvests have declined, with similar patterns occurring in the Canadian Maritime Provinces (Meister and Flagg 1997). An average of 62% of the annual landings of U.S. commercial harvest since 1993 have come from the Chesapeake Bay (personal communication from the National Marine Fisheries Service, Fisheries Statistics Division, 9 February 2015). In 2013, Virginia commercial landings were approximately 100,298 lbs; since mandatory reporting began in 1993, average annual landings in Virginia have been 193,200 lbs or 19% …


Tracking Decadal Changes In Striped Bass Recruitment: A Calibration Study Of Seine Surveys In Chesapeake Bay, Mary C. Fabrizio, Troy D. Tuckey, Olivia M. Philips, Brian K. Gallagher Mar 2017

Tracking Decadal Changes In Striped Bass Recruitment: A Calibration Study Of Seine Surveys In Chesapeake Bay, Mary C. Fabrizio, Troy D. Tuckey, Olivia M. Philips, Brian K. Gallagher

Reports

In this study we estimated calibration factors necessary to maintain the long‐term integrity of the juvenile striped bass surveys in the Chesapeake Bay region. These surveys provide annual indices of recruitment (estimated as juvenile fish abundance in summer) and are used by fisheries managers in Virginia and Maryland to inform adjustments of annual harvest limits for striped bass from the commercial and recreational fisheries in Chesapeake Bay. During the multi‐decadal history of the survey, a potentially influential change occurred: VIMS deployed a net (the VA net) with a mesh material that differed from the standard net that MD DNR continued …


Temperature Selectivity And Movement Patterns Of Speckled Trout, Patrick E. Mcgrath, Eric J. Hilton Mar 2017

Temperature Selectivity And Movement Patterns Of Speckled Trout, Patrick E. Mcgrath, Eric J. Hilton

Reports

Speckled trout (Cynoscion nebulosus) is the focus of an important recreational fishery in the southeastern United States. Speckled trout in Virginia has been cited as both a transitional population and as a mostly non-migratory population. The degree of residency is important to understand for the effective management of the species. Management of speckled trout has also been marred by cold-stun events which can kill a significant portion of the stock and have detrimental localized effects. Virginia is the northern extent of speckled trout populations and is the most likely portion of its range to experience cold-stun events. Virginia water temperatures …


Virginia Fishery Resource Grant Program 2016, Virginia Fishery Resource Grant Program, Virginia Institute Of Marine Science Feb 2017

Virginia Fishery Resource Grant Program 2016, Virginia Fishery Resource Grant Program, Virginia Institute Of Marine Science

Reports

No abstract provided.


Projections Of Climate-Driven Changes In Tuna Vertical Habitat Based On Species-Specific Differences In Blood Oxygen Affinity, Kas Mislan, Ca Deutsch, Richard Brill, Jp Dunne, Jl Sarmiento Jan 2017

Projections Of Climate-Driven Changes In Tuna Vertical Habitat Based On Species-Specific Differences In Blood Oxygen Affinity, Kas Mislan, Ca Deutsch, Richard Brill, Jp Dunne, Jl Sarmiento

VIMS Articles

Oxygen concentrations are hypothesized to decrease in many areas of the ocean as a result of anthropogenically driven climate change, resulting in habitat compression for pelagic animals. The oxygen partial pressure, pO(2), at which blood is 50% saturated (P-50) is a measure of blood oxygen affinity and a gauge of the tolerance of animals for low ambient oxygen. Tuna species display a wide range of blood oxygen affinities (i.e., P-50 values) and therefore may be differentially impacted by habitat compression as they make extensive vertical movements to forage on subdaily time scales. To project the effects of end-of-the-century climate change …


Extensions And Applications Of Mean Length Mortality Estimators For Assessment Of Data-Limited Fisheries, Quang C. Huynh Jan 2017

Extensions And Applications Of Mean Length Mortality Estimators For Assessment Of Data-Limited Fisheries, Quang C. Huynh

Dissertations, Theses, and Masters Projects

For data-limited fisheries, length-based mortality estimators are attractive as alternatives to age-structured models due to the simpler data requirements and ease of use of the former. This dissertation develops new extensions of mean length-based mortality estimators and applies them to federally-managed stocks in the southeastern U.S. and U.S. Caribbean.

Chapter 1 presents a review of length-based methods from the literature. Common themes regarding the methodology, assumptions, and diagnostics in these length-based methods are discussed. In Chapter 2, a simulation study evaluates the performance of the length-converted catch curve (LCCC), Beverton-Holt equation (BHE), and Length Based-Spawner Potential Ratio (LB-SPR) over a …


Describe If Commercial Low-Frequency Electrofishing Affects The Catch Of Blue Catfish Hoop-Net Fishery, George Trice Iv Jan 2017

Describe If Commercial Low-Frequency Electrofishing Affects The Catch Of Blue Catfish Hoop-Net Fishery, George Trice Iv

Reports

The blue catfish Ictalurus furcatus was first introduced to Virginia tidal waters in the 1974 and currently inhabit all major Virginia tributaries of the Chesapeake Bay (Jenkins and Burkhead 1994, Schloesser et al. 2011). More recently blue catfish have spread to Maryland waters and are multiplying at an alarming rate. The James River tributary has the largest number of blue catfish (Schloesser et al. 2011) in Virginia. The amount of blue catfish inhabiting the James River in unknown but is likely to be over five million (Fabrizio et al. 2009, Greenlee 2011) and blue catfish are estimated to be over …


Vaccine Effects On Heterogeneity In Susceptibility And Implications For Population Health Management, Ke Langwig, Ar Wargo, Dr Jones, Jr Viss, Bj Rutan, Et Al. Jan 2017

Vaccine Effects On Heterogeneity In Susceptibility And Implications For Population Health Management, Ke Langwig, Ar Wargo, Dr Jones, Jr Viss, Bj Rutan, Et Al.

VIMS Articles

Heterogeneity in host susceptibility is a key determinant of infectious disease dynamics but is rarely accounted for in assessment of disease control measures. Understanding how susceptibility is distributed in populations, and how control measures change this distribution, is integral to predicting the course of epidemics with and without interventions. Using multiple experimental and modeling approaches, we show that rainbow trout have relatively homogeneous susceptibility to infection with infectious hematopoietic necrosis virus and that vaccination increases heterogeneity in susceptibility in a nearly all-or-nothing fashion. In a simple transmission model with an R-0 of 2, the highly heterogeneous vaccine protection would cause …


Advancing The Link Between Ocean Connectivity, Ecological Function And Management Challenges, M Hidalgo, Dm Kaplan, La Kerr, Jr Watson, Cb Paris, Hi Browman Jan 2017

Advancing The Link Between Ocean Connectivity, Ecological Function And Management Challenges, M Hidalgo, Dm Kaplan, La Kerr, Jr Watson, Cb Paris, Hi Browman

VIMS Articles

Ocean connectivity is a dynamic and rapidly evolving field of research in marine science, partly because there is an increasing demand for information on connectivity that informs effective assessment and management of marine resources. Achieving this will require a better alignment between ocean connectivity tools and developments and the needs and challenges of assessments and conservation. For these reasons, the ICES Journal of Marine Science solicited contributions to the article theme set (TS), "Beyond ocean connectivity." We briefly summarize the nine articles that appear herein, grouping them into four general topics: methodological advances, population dynamics and assessment implications of connectivity, …