Life Sciences Commons^™

Comparison Of Age-Frequency Distributions For Ocean Quahogs Arctica Islandica On The Western Atlantic Us Continental Shelf, Sara M. Pace, Eric N. Powell, Roger L. Mann, M. Chase Long

VIMS Articles

Geographic differences in the age structure of 4 populations of ocean quahogs Arctica islandica throughout the range of the stock within the US exclusive economic zone were examined. The ages of animals fully recruited to the commercial fishery (≥80 mm shell length) were estimated using annual growth lines in the hinge plate. The observed age frequency from each site was used to develop an age−length key enabling reconstruction of the population age frequency for the site. Within-site variability was high for both age-at-length and length-at-age; a single age−length key could not be applied and would not result in accurate age …

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 …

Collection Techniques For The Analyses Of Pathogens In Crustaceans, Jeffrey D. Shields

VIMS Articles

Outbreaks of diseases have been reported from a number of ecologically or commercially important crustaceans in tropical, temperature, and boreal waters. The etiology of a disease is often unknown prior to these outbreaks and the effect of the pathogen on the host population is poorly understood. Various techniques can be used to collect, identify, and monitor host populations for pathogens. These include classical methods, such as visual or histological assessment, to more refined techniques, such as simple and quantitative polymerase chain reaction assays. The strengths and weaknesses of the different methods are presented as well as some general guidelines for …

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 …

Integration Of Swimming Kinematics And Ram Suspension Feeding In A Model American Paddlefish, Polyodon Spathula, Grant Emerson Haines, S. Laurie Sanderson

Arts & Sciences Articles

Ram suspension-feeding fishes swim with an open mouth to force water through the oral cavity and extract prey items that are too small to be pursued individually. Recent research has indicated that, rather than using a dead-end mechanical sieve, American paddlefish (Polyodon spathula) employ vortical cross-step filtration. In this filtration mechanism, vortical flow that is generated posterior to the branchial arches organizes crossflow filtration processes into a spatial structure across the gill rakers. Despite the known impact of locomotor kinematics on fluid flow around the bodies of swimming fish, the effects of locomotor kinematics on filtration mechanisms in …

Tidal Habitats Support Large Numbers Of Invasive Blue Catfish In A Chesapeake Bay Subestuary, Troy D. Tuckey, Mary C. Fabrizio, Robert J. Latour, Alicia J. Norris, Gary C. White

VIMS Articles

The introduction of a non-native freshwater fish, blue catfish Ictalurus furcatus, in tributaries of Chesapeake Bay resulted in the establishment of fisheries and in the expansion of the population into brackish habitats. Blue catfish are an invasive species in the Chesapeake Bay region, and efforts are underway to limit their impacts on native communities. Key characteristics of the population (population size, survival rates) are unknown, but such knowledge is useful in understanding the impact of blue catfish in estuarine systems. We estimated population size and survival rates of blue catfish in tidal habitats of the James River subestuary. We tagged …

Understanding Changes In Seagrass Communities, Sarah Nuss, Celeste Venolia

VIMS Articles

Seagrass is an incredibly valuable habitat in the Chesapeake Bay. Students will use mock seagrass patches, modeled after a research transect along Goodwin Island, Virginia, to analyze change in seagrass percent cover during, and following, a major die-off event in 2010. Students also analyze water quality graphs from the same time period to help them determine why the die-off may have occurred.

New Insight Into The Transmission Dynamics Of The Crustacean Pathogen Hematodinium Perezi (Dinoflagellata) Using A Novel Sentinel Methodology, Jeffrey D. Shields, Juan Pablo Huchin-Mian Huchin-Mian, Pattie A. O’Leary, Hamish J. Small

VIMS Articles

Hematodinium perezi causes disease and mortality in several decapod crustaceans along the eastern seaboard and Gulf coast of the USA. The route of transmission of the parasite is unknown, but infections exhibit a sharp seasonal cycle in its primary host, the blue crab Callinectes sapidus, that indicates the possibility of a short transmission period in its life cycle. We developed a sentinel methodology based on the use of naïve, uninfected, early benthic juvenile crabs (instars C1 to C10) to investigate the transmission of H. perezi. Crabs were collected from a non-endemic site, held for a short period for evaluation, and …

Submersed Aquatic Vegetation In Chesapeake Bay: Sentinel Species In A Changing World, R J. Orth, William C. Dennison, Jonathan S. Lefcheck, Cassie Gurbisz, Michael Hannam, Jennifer Keisman, J. Brooke Landry, Ken Moore, Rebecca R. Murphy, Christopher J. Patrick, Jeremy Testa, Donald E. Weller, David J. Wilcox

VIMS Articles

Chesapeake Bay has undergone profound changes since European settlement. Increases in human and livestock populations, associated changes in land use, increases in nutrient loadings, shoreline armoring, and depletion of fish stocks have altered the important habitats within the Bay. Submersed aquatic vegetation (SAV) is a critical foundational habitat and provides numerous benefits and services to society. In Chesapeake Bay, SAV species are also indicators of environmental change because of their sensitivity to water quality and shoreline development. As such, SAV has been deeply integrated into regional regulations and annual assessments of management outcomes, restoration efforts, the scientific literature, and popular …

Satellite Tracking And Site Fidelity Of Short Ocean Sunfish, Mola Ramsayi, In The Galapagos Islands, Tierney M. Thys, Alex R. Hearn, Kevin C. Weng, John P. Ryan, César A Peñaherrera-Palm

VIMS Articles

Ocean sunfishes, with their peculiar morphology, large size, and surface habits, are valuable assets in ecotourism destinations worldwide. This study investigates site fidelity and long-range movements of short ocean sunfish, Mola ramsayi (Giglioli 1883), at Punta Vicente Roca (PVR) off Isabela Island in the Galapagos Islands. Five individuals were tracked between 32 and 733 days using ultrasonic receivers and transmitters. Two of the 5 were also tracked with towed pop-off satellite tags. One travelled to the equatorial front covering 2700 km in 53 days, with dive depths in the upper 360 m at temperatures between 9.2°C and 22°C. During its …

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).

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 …

Role Of Habitat And Predators In Maintaining Functional Diversity Of Estuarine Bivalves, Cassandra N. Glaspie, Rochell D. Seitz

VIMS Articles

Habitat loss is occurring rapidly in coastal systems worldwide. In Chesapeake Bay, USA, most historical oyster reefs have been decimated, and seagrass loss is expected to worsen due to climate warming and nutrient pollution. This loss of habitat may result in declining diversity, but whether diversity loss will equate to loss in ecosystem function is unknown. A bivalve survey was conducted in a variety of habitat types (seagrass, oyster shell, shell hash, coarse sand, detrital mud) in 3 lower Chesapeake Bay sub-estuaries from spring 2012 through summer 2013 to examine the correlation between bivalve densities, habitat type, habitat volume (of …

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 …

Climate Change Impacts On Southern Ross Sea Phytoplankton Composition, Productivity, And Export, Daniel E. Kaufman, Marjorie A. M. Friedrichs, Walker O. Smith Jr., Eileen E. Hofmann, Michael S. Dinniman, John C. P. Hemmings

VIMS Articles

The Ross Sea, a highly productive region of the Southern Ocean, is expected to experience warming during the next century along with reduced summer sea ice concentrations and shallower mixed layers. This study investigates how these climatic changes may alter phytoplankton assemblage composition, primary productivity, and export. Glider measurements are used to force a one-dimensional biogeochemical model, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance is evaluated with glider observations, and experiments are conducted using projections of physical drivers for mid-21st and late-21st century. These scenarios reveal a 5% increase in primary productivity …

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 …

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 …

2016 Annual Awards, Virginia Institute Of Marine Science

Miscellaneous

The Annual Awards ceremony is an occasion in which new employees and volunteers are introduced, employee service is recognized and student and faculty awards are presented.

Partners In Natural Resource Management: The Virginia Institute Of Marine Science And The Commonwealth Of Virginia, Virginia Institute Of Marine Science

Miscellaneous

Produced by the Office of Research and Advisory Services, Partners in Natural Resources Management identifies all of the sections of Virginia legislation in which the Virginia Institute of Marine Science is named in relation to our advisory mandate.

Oyster (Crassostrea Virginica [Gmelin, 1791]) Mortality At Prolonged Exposures To High Temperature And Low Salinity, Melissa Southworth, M. Chase Long, Roger L. Mann

VIMS Articles

Mortality of two size classes (35 mm) of eastern oysters Crassostrea virginica when exposed to combinations of low salinity (1, 2, 3, and 4) for extended periods (up to 30 days) at summer water temperatures typical of the Virginia Chesapeake Bay subestuaries was examined. A critical salinity-temperature combination of less than two at greater than 28 degrees C for more than 1 wk exposure for oyster mortality is suggested. A review of limited historical salinity-temperature tolerance data suggest selection of local populations of oysters having differing salinity tolerances. Such selection may prove critical to persistence of low-salinity populations in the …

Spatiotemporal Abundance Patterns And Ecological Drivers Of A Nearshore U.S. Atlantic Fish And Invertebrate Assemblage, Mark A. Stratton

Dissertations, Theses, and Masters Projects

Taking an ecosystem approach to fisheries requires the consideration of relevant ecological processes within research and assessment frameworks. Processes affecting ecosystem productivity can be categorized as biophysical (climate variability, primary production), exploitative (fishing), or trophodynamic (food web interactions). This dissertation incorporates these three governing processes to characterize spatiotemporal diversity and population abundance trends for multiple demersal fish and invertebrate species that inhabit the nearshore zone (15-30 ft. depth) along portions of the U.S. Atlantic east coast.

Two large marine ecosystems (LMEs) encompass the U.S. East coast – the Southeast and Northeast U.S. Continental Shelf LMEs. The level of connectivity within …

Integrating Empirical Data And Ocean Drift Models To Better Understand Sea Turtle Strandings In Virginia, Bianca Silva Santos

Dissertations, Theses, and Masters Projects

Hundreds of stranded turtles wash up deceased on Virginia’s coastline each year, yet the causes of most stranding events are poorly understood. In this thesis, a carcass drift model was developed for the Chesapeake Bay, Virginia, to predict likely locations of mortality from coastal sea turtle stranding records. First, field studies were carried out to better parameterize the drift characteristics of buoyant sea turtle carcasses, namely, probable oceanic drift times and the impact of direct wind forcing on carcass drift. Based on the duration that tethered, free-floating turtle carcasses were buoyant, we determined that oceanic drift duration of turtle carcasses …

Mutualism Between Ribbed Mussels And Cordgrass Enhances Salt Marsh Nitrogen Removal, Donna M. Bilkovic, Molly Mitchell, Robert E. Isdell, Matthew Schliep, Ashley R. Smyth

VIMS Articles

Salt marsh ecosystems have declined globally and are increasingly threatened by erosion, sea level rise, and urban development. These highly productive, physically demanding ecosystems are populated by core species groups that often have strong trophic interactions with implications for ecosystem function and service provision. Positive interactions occur between ribbed mussels (Geukensia demissa) and cordgrass (Spartina alterniflora). Mussels transfer particulate nitrogen from the water column to the marsh sediments, which stimulates cordgrass growth, and cordgrass provides predator and/or heat stress refuge for mussels. Here, we test mussel facilitation of two functions in salt marshes that relate to N removal: microbial denitrification …

Population And Reproductive Biology Of The Channeled Whelk, Busycotypus Canaliculatus, In The Us Mid-Atlantic, Robert A. Fisher, David Rudders

VIMS Articles

Channeled whelks, Busycotypus canaliculatus, support commercial fisheries throughout their range along the US Atlantic seaboard. Given the modest amounts of published information available on channeled whelk, this study focuses on understanding the temporal and spatial variations in growth and reproductive biology in the Mid-Atlantic region. Channeled whelks were sampled from three inshore commercially harvested resource areas in the US Mid-Atlantic: Ocean City, MD (OC); Eastern Shore of Virginia (ES); and Virginia Beach, VA (VB). The largest whelk measured 230-mm shell length (SL) and was recorded from OC. Mean SL was largest in OC site (158.1 mm), followed by ES (137.6 …

Associated Dataset: Climate Change Impacts On Southern Ross Sea Phytoplankton Composition, Productivity And Export, Daniel E. Kaufman, Marjorie A.M. Friedrichs, Walker O. Smith Jr., Eileen E. Hofmann, Michael S. Dinniman, John C.P. Hemmings

Data

This dataset includes data used in the publication Kaufman et al., 2017, JGR-Oceans, which investigates how these climatic changes in the Ross Sea, Antarctica, may alter phytoplankton composition, primary productivity and export. A one-dimensional version of the Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification was adapted for use in the Ross Sea (MEDUSA-RS). Glider measurements were used to force MEDUSA-RS, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance was evaluated with glider observations, and experiments were conducted using projections of physical drivers for mid- and late-21st century. Additional scenarios examined the …

Age, Growth And Reproduction Of Western North Atlantic Butterfly Rays (Myliobatiformes: Gymnuridae), With The Description Of Two New Species, Kristene Teal Parsons

Dissertations, Theses, and Masters Projects

Batoid fishes are among the most threatened and least understood chondrichthyan species worldwide due to their large body size, conservative life-history characteristics, and predominantly coastal distributions where fishing and habitat degradation threaten the stability of populations. A lack of empirical life history data is widespread across batoid taxa — nearly half of all species are considered data deficient, thus hindering species assessments and the development of effective management strategies. Furthermore, many batoid taxa are in need of taxonomic re-examination. Increasing our understanding of life history traits that determine population productivity, such as age and size at maturity, growth rate, and …

Juvenile Blue Crab (Callinectes Sapidus) Response To Altered Nursery Habitat, Megan Wood

Dissertations, Theses, and Masters Projects

Habitats of Chesapeake Bay have been altered due to anthropogenic impacts and climate change. Due to these human disturbances, seagrasses have been extirpated from many areas in lower Chesapeake Bay and persisting beds face future losses as water temperatures continue to rise. Further loss of seagrass habitat will negatively impact juvenile blue crabs (Callinectes sapidus) that use seagrass beds as nursery grounds. Habitat degradation allows for more successful introductions of exotic species, and the communities formed from the mixing of native and exotic species are known as emerging ecosystems. Gracilaria vermiculophylla, an exotic macroalga, may be an emerging nursery habitat …

Preliminary Estimate Of Contribution Of Arctic Nitrogen Fixation To The Global Nitrogen Budget, Rachel E. Sipler, Donglai Gong, Se Baer, Mp Sanderson, Qn Roberts, M Mulholland, Da Bronk

VIMS Articles

Dinitrogen (N-2) fixation is the source of all biologically available nitrogen on earth, and its presence or absence impacts net primary production and global biogeochemical cycles. Here, we report rates of 3.5-17.2 nmol N L-1 d(-1) in the ice-free coastal Alaskan Arctic to show that N-2 fixation in the Arctic Ocean may be an important source of nitrogen to a seasonally nitrogen-limited system. If widespread in surface waters over ice-free shelves throughout the Arctic, N-2 fixation could contribute up to 3.5 Tg N yr(-1) to the Arctic nitrogen budget. At these rates, N-2 fixation occurring in ice-free summer waters would …

Redox Reactions And Weak Buffering Capacity Lead To Acidification In The Chesapeake Bay, Wei-Jun Cai, Wei-Jen Huang, George W. Luther Iii, Denis Pierrot, Ming Li, Jeremy Testa, Ming Xue, Andrew Joesoef, Roger L. Mann, Jean Brodeur, Yuan-Yuan Xu, Baoshan Chen, Najid Hussain, George G. Waldbusser, Jeffery Cornwell, W. Michael Kemp

VIMS Articles

The combined effects of anthropogenic and biological CO2 inputs may lead to more rapid acidification in coastal waters compared to the open ocean. It is less clear, however, how redox reactions would contribute to acidification. Here we report estuarine acidification dynamics based on oxygen, hydrogen sulfide (H2S), pH, dissolved inorganic carbon and total alkalinity data from the Chesapeake Bay, where anthropogenic nutrient inputs have led to eutrophication, hypoxia and anoxia, and low pH. We show that a pH minimum occurs in mid-depths where acids are generated as a result of H2S oxidation in waters mixed upward from the anoxic depths. …

Microbial Community Response To Terrestrially Derived Dissolved Organic Matter In The Coastal Arctic, Rachel E. Sipler, Colleen T. E. Kellogg, Tara L. Connelly, Qn Roberts, Patricia L. Yager, Deborah A. Bronk

VIMS Articles

Warming at nearly twice the global rate, higher than average air temperatures are the new 'normal' for Arctic ecosystems. This rise in temperature has triggered hydrological and geochemical changes that increasingly release carbon-rich water into the coastal ocean via increased riverine discharge, coastal erosion, and the thawing of the semipermanent permafrost ubiquitous in the region. To determine the biogeochemical impacts of terrestrially derived dissolved organic matter (tDOM) on marine ecosystems we compared the nutrient stocks and bacterial communities present under ice-covered and ice-free conditions, assessed the lability of Arctic tDOM to coastal microbial communities from the Chukchi Sea, and identified …