Life Sciences Commons^™

Virginia Seafood Sustainability, Samantha E. Askin, Robert A. Fisher

Reports

Virginia’s commercial fisheries operate sustainability under a suite of management tools based upon information received from marine scientists and fishery managers who regularly conduct biological sampling of fish while tracking commercial landings and other gathering of required information. Analyses of fishing effort and overall stock conditions, as well as formulas designed to calculate threshold limits for maintaining sustainable stocks are regularly performed. Restrictions on seasons, size, days at sea, and gear are imposed as needed to achieve management supporting long-term biological sustainability.

Estimated Consumer Sensory Shell Life Of Fresh Blue Catfish Filets Stored In Ice (Ictalurus Furcatus), Robert A. Fisher

Reports

Blue Catfish (Ictalurus furcatus) is the largest species of catfish in North America where it is native to the Mississippi, Missouri, and Ohio river drainages. It was introduced in fresh water Virginia tributaries of the Chesapeake Bay to enhance recreational fisheries in the 1970’s, from which significant recreational and commercial wild caught catfish fisheries developed. Since introduction, Blue catfish populations have expanded from upriver freshwater habitat to brackish-water sub-estuaries with reports of blue catfish in the Chesapeake Bay proper. Blue catfish are voracious, opportunistic predators feeding on a variety of natural prey items, including native fish and shellfish species, and …

Intertidal Zonation Of Hemichordates In Soft Sediments, Kharis R. Schrage, Juselyn D. Tupik, Jonathan D. Allen

Arts & Sciences Articles

Intertidal zonation of organisms is well studied on rocky shores but less so in soft sediment communities. On rocky shores, communities are two dimensional, with biotic factors such as competition and predation setting the lower bound of a zone, whereas abiotic factors such as desiccation set the upper bound. In soft sediment communities, these patterns persist, but with a dynamic three-dimensional ecosystem occupied by mobile infaunal organisms, zonation can be more difficult to quantify and detect. Hemichordate worms, however, deposit fecal casts at the surface, which can be easily identified and counted, making them a potential model system for identifying …

Estuarine Microbiomes And Biogeochemistry: Impacts Of Spatiotemporal Variation, Algal Blooms, And Microplastics, Samantha Grace Fortin

Dissertations, Theses, and Masters Projects

Estuaries are biogeochemical hotspots connecting terrestrial and coastal ecosystems. Anthropogenic disturbances, including increased nitrogen loading and plastic pollution, may have significant impacts on estuarine carbon and nitrogen cycling by altering microbiome structure and functions. The overarching goal of this dissertation was to examine how microbiomes and their associated biogeochemical processes are influenced by natural variation and anthropogenic disturbances in the York River Estuary (YRE). In chapter 2, spatial and temporal variation in benthic microbiomes and the rates of denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) were examined to determine biotic and abiotic drivers of nitrogen …

A Rapid Phenotype Change In The Pathogen Perkinsus Marinus Was Associated With A Historically Significant Marine Disease Emergence In The Eastern Oyster, Ryan Carnegie, Susan E. Ford, Rita K. Crockett, Peter R. Kingsley-Smith, Lydia M. Bienlien, Lucia S.L. Safi, Laura A. Whitefleet-Smith, Eugene M. Burreson

VIMS Articles

The protozoan parasite Perkinsus marinus, which causes dermo disease in Crassostrea virginica, is one of the most ecologically important and economically destructive marine pathogens. The rapid and persistent intensification of dermo in the USA in the 1980s has long been enigmatic. Attributed originally to the effects of multi-year drought, climatic factors fail to fully explain the geographic extent of dermo’s intensification or the persistence of its intensified activity. Here we show that emergence of a unique, hypervirulent P. marinus phenotype was associated with the increase in prevalence and intensity of this disease and associated mortality. Retrospective histopathology of …

A Decade Of Incorporating Social Sciences In The Integrated Marine Biosphere Research Project (Imber): Much Done, Much To Do?, Ingrid Van Putten, Rachel Kelly, (...), Kevin Weng, Et Al

VIMS Articles

Successful management and mitigation of marine challenges depends on cooperation and knowledge sharing which often occurs across culturally diverse geographic regions. Global ocean science collaboration is therefore essential for developing global solutions. Building effective global research networks that can enable collaboration also need to ensure inter- and transdisciplinary research approaches to tackle complex marine socio-ecological challenges. To understand the contribution of interdisciplinary global research networks to solving these complex challenges, we use the Integrated Marine Biosphere Research (IMBeR) project as a case study. We investigated the diversity and characteristics of 1,827 scientists from 11 global regions who were attendees at …

Modeling Changes In Baleen Whale Seasonal Abundance, Timing Of Migration, And Environmental Variables To Explain The Sudden Rise In Entanglements In California, Kaytlin Ingman, Ellen Hines, Piero L. F. Mazzini, Et Al

VIMS Articles

We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, regional upwelling, and basin-scale climate conditions. Using 24 years of daily whale counts collected from Southeast Farallon Island, we developed negative binomial regression models to evaluate trends in local whale sightings over time. We then used linear models to assess trends in the timing of …

Ecological Monitoring Program At Vims Esl : Annual Report 2020, Paige G. Ross, Richard A. Snyder

Reports

An Ecological Monitoring Program (EMP) has been established at the Virginia Institute of Marine Science Eastern Shore Laboratory (VIMS ESL) for the coastal environment near the Wachapreague lab. The goals of the initiative are to 1) provide status and trends information to scientists who study and regulators who manage Virginia’s marine resources, 2) provide a scientific context for short-term research and grant proposals 3) provide pedagogical enrichment to educators for their classes, and 4) build capacity in staff expertise and training of interns and students at VIMS ESL.

The program formalizes and standardizes data collection for a long-term status and …

Variation In Seagrass-Associated Macroinvertebrate Communities Along The Gulf Coast Of Peninsular Florida: An Exploration Of Patterns And Ecological Consequences, Savanna C. Barry, A. Challen Hyman, Charles A. Jacoby, Laura K. Reynolds, Mark Kowalewski, Thomas K. Frazer

VIMS Articles

Seagrasses form vast meadows of structurally complex habitat that support faunal communities with greater numbers of species and individuals than nearby unstructured habitats. The Gulf coast of peninsular Florida represents a natural laboratory ideally suited to the study of processes that shape seagrass-associated invertebrate and fish communities within meadows of a single species of seagrass, Thalassia testudinum. This suitability arises from a pronounced structural and chemical gradient that exists over ecologically relevant spatial and temporal scales, as revealed by extensive monitoring of water quality and seagrass. We hypothesized that seagrass-associated invertebrate communities would vary across five estuarine systems spread …

Spatiotemporal Distribution Of Phycotoxins And Their Co-Occurrence Within Nearshore Waters, Michelle D. Onofrio, Todd A. Egerton, Kimberly S. Reece, Sarah K.D. Pease, Marta P. Sanderson, William Jones Iii, Evan Yeargan, Amanda Roach, Caroline Dement, William G. Reay, Allen R. Place, Juliette L. Smith

VIMS Articles

Harmful algal blooms (HABs), varying in intensity and causative species, have historically occurred throughout the Chesapeake Bay, U.S.; however, phycotoxin data are sparse. The spatiotemporal distribution of phycotoxins was investigated using solid-phase adsorption toxin tracking (SPATT) across 12 shallow, nearshore sites within the lower Chesapeake Bay and Virginia's coastal bays over one year (2017-2018). Eight toxins, azaspiracid-1 (AZA1), azaspiracid-2 (AZA2), microcystin-LR (MC-LR), domoic acid (DA), okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-2 (PTX2), and goniodomin A (GDA) were detected in SPATT extracts. Temporally, phycotoxins were always present in the region, with at least one phycotoxin group (i.e., consisting of OA and …

Ribbed Mussel Geukensia Demissa Population Response To Living Shoreline Design And Ecosystem Development, Donna M. Bilkovic, Robert Isdell, Amanda G. Guthrie, Molly Mitchell, Randolph M. Chambers

VIMS Articles

Coastal communities increasingly invest in natural and nature-based features (e.g., living shorelines) as a strategy to protect shorelines and enhance coastal resilience. Tidal marshes are a common component of these strategies because of their capacity to reduce wave energy and storm surge impacts. Performance metrics of restoration success for living shorelines tend to focus on how the physical structure of the created marsh enhances shoreline protection via proper elevation and marsh plant presence. These metrics do not fully evaluate the level of marsh ecosystem development. In particular, the presence of key marsh bivalve species can indicate the capability of the …

Comparative Study Of The Hemolymph Microbiome Between Live And Recently Dead American Lobsters Homarus Americanus, Jibom Jung, Patrick M. Gillevet, Masoumeh Sikaroodi, Jamal Andrews, Bk Song, Jeffrey D. Shields

VIMS Articles

Lobsters and other crustaceans do not have sterile hemolymph. Despite this, little is known about the microbiome in the hemolymph of the lobster Homarus americanus. The purpose of this study was to characterize the hemolymph microbiome in lobsters. The lobsters were part of a larger study on the effect of temperature on epizootic shell disease, and several died during the course of the study, providing an opportunity to examine differences in the microbiomes between live and recently dead (1−24 h) animals. The hemolymph microbiomes of live lobsters was different from those in dead animals and both were different from the …

The Status Of Virginia’S Public Oyster Resource 2020, Melissa Southworth, Roger L. Mann

Reports

The Virginia Institute of Marine Science (VIMS) monitors recruitment of the Eastern oyster, Crassostrea virginica (Gmelin, 1791), annually from late spring through early fall, by deploying spatfall[1] (settlement and recruitment of larval oysters to the post metamorphic form termed spat) collectors (shellstrings) at various sites in three Virginia western Chesapeake Bay tributaries. The survey provides an estimate of a particular area’s potential for receiving a "strike" or settlement (set) of oysters on the bottom and helps describe the timing of recruitment events in a given year. Information obtained from this monitoring effort provides an overview of long-term recruitment …

Monitoring The Abundance Of American Shad And River Herring In Virginia’S Rivers 2020 Annual Report, Eric J. Hilton, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the twenty-third 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 2020, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007, ASMFC 2020).

We also report on two fisheryindependent monitoring programs using anchor gillnets in the Rappahannock River (year 3) and the Chickahominy River (year 6; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of …

Campus Map Virginia Institute Of Marine Science, William & Mary Gloucester Point September 2021, Virginia Institute Of Marine Science

Miscellaneous

No abstract provided.

Improving Observation, Assessment, And Management Of Atlantic Coastal Sharks, Cassidy Dawn Peterson

Dissertations, Theses, and Masters Projects

Coastal sharks represent a group of stocks for which observation, assessment, and management are particularly challenging. Large distributional ranges, complex migratory behavior, low economic value, and relatively few observations in fishery independent surveys hinder relative abundance estimation. Assessing stock status of coastal sharks is encumbered by limited data availability, data quality, and knowledge of life history strategy. Further, coastal sharks are challenging to manage due to their slow intrinsic population growth rates, competing stakeholder interests, history of overexploitation, and in some cases, subjection to international exploitation. This dissertation aimed to improve the capacity to observe relative abundance of coastal sharks. …

Changes In Plant Communities Of Low-Salinity Tidal Marshes In Response To Sea-Level Riselow-Salinity Tidal Marshes In Response To Sea-Level Rise, Abbey Humphreys, Adrianna L. Gorsky, Donna M. Bilkovic, Randolph M. Chambers

VIMS Articles

As sea-level rises, low-salinity tidal marshes experience greater flooding with more saline water. In the Chesapeake Bay estuary, we compared the 1980 and 2014 tidal marsh inventories (TMIs) of plant communities from James City County, Virginia, USA, with respect to the spatial distribution of two species—the invasive reed Phragmites australis and native salt marsh grass Spartina alterniflora–plus overall species richness. Since the 1980 TMI, the total area of low-salinity tidal marshes in which P. australis occurred increased from 0.46 km² to 6.30 km² in 2014. Between TMIs, however, the total area of low-salinity marshes occupied by …

Molecular Mechanism Of Oil Induced Growth Inhibition In Diatoms Using Thalassiosira Pseudonana As The Model Species, Manoj Kamalanathan, Savannah Mapes, Jessica Hillhouse, Et Al

VIMS Articles

The 2010 Deepwater Horizon oil-spill exposed the microbes of Gulf of Mexico to unprecedented amount of oil. Conclusive evidence of the underlying molecular mechanism(s) on the negative effects of oil exposure on certain phytoplankton species such as Thalassiosira pseudonana is still lacking, curtailing our understanding of how oil spills alter community composition. We performed experiments on model diatom T. pseudonana to understand the mechanisms underpinning observed reduced growth and photosynthesis rates during oil exposure. Results show severe impairment to processes upstream of photosynthesis, such as light absorption, with proteins associated with the light harvesting complex damaged while the pigments were …

Advancing The Sea Ice Hypothesis: Trophic Interactions Among Breeding Pygoscelis Penguins With Divergent Population Trends Throughout The Western Antarctic Peninsula, Kristen B. Gorman, Kate E. Ruck, Tony D. Williams, William R. Fraser

VIMS Articles

We evaluated annual and regional variation in the dietary niche of Pygoscelis penguins including the sea ice-obligate Adélie penguin (Pygoscelis adeliae), and sea ice-intolerant chinstrap (Pygoscelis antarcticus) and gentoo (Pygoscelis papua) penguins, three species that nest throughout the western Antarctic Peninsula (AP) to test the sea ice trophic interaction hypothesis, which posits that penguin breeding populations with divergent trends, i.e., declining or increasing, are reliant on differing food webs. Our study relies on values of naturally occurring carbon (13C/12C, δ13C) and nitrogen (15N/14N, δ15N) stable isotopes as integrated proxies of penguin food webs measured
over three years at three different …

The Extent Of Seasonally Suitable Habitats May Limit Forage Fish Production In A Temperate Estuary, Mary C. Fabrizio, Troy D. Tuckey, Aaron J. Bever, Michael L. Macwilliams

VIMS Articles

The sustained production of sufficient forage is critical to advancing ecosystem-based management, yet factors that affect local abundances and habitat conditions necessary to support aggregate forage production remain largely unexplored. We quantified suitable habitat in the Chesapeake Bay and its tidal tributaries for four key forage fishes: juvenile spotted hake Urophycis regia, juvenile spot Leiostomus xanthurus, juvenile weakfish Cynoscion regalis, and bay anchovy Anchoa mitchilli. We used information from monthly fisheries surveys from 2000 to 2016 coupled with hindcasts from a spatially interpolated model of dissolved oxygen and a 3-D hydrodynamic model of the Chesapeake Bay …

Temporal And Spatial Variability Of Phytoplankton And Mixotrophs In A Temperate Estuary, Nicole C. Millette, Marcella Da Costa, Jordan W. Mora, Rebecca J. Gast

VIMS Articles

A significant proportion of phototrophic species are known to be mixotrophs: cells that obtain nutrients through a combination of photosynthesis and prey ingestion. Current methods to estimate mixotroph abundance in situ are known to be limited in their ability to help identify conditions that favor mixotrophs over strict autotrophs. For the first time, we combine microscopic analysis of phototrophic taxa with immunoprecipitated bromodeoxyuridine (BrdU)labeled DNA amplicon sequencing to identify and quantify active and putative mixotrophs at 2 locations in a microtidal temperate estuary. We analyze these data to examine spatial and temporal variability of phytoplankton and mixotrophs. Microscopy-based phototrophic diversity …

Environmentally-Determined Production Frontiers And Lease Utilization In Virginia's Eastern Oyster Aquaculture Industry, Jennifer Beckensteiner, Andrew M. Scheld, Pierre St-Laurent, Marjorie A.M. Friedrichs, David M. Kaplan

VIMS Articles

During the last decade, oyster aquaculture has rebounded in Virginia and has been associated with an increase in subaqueous leased area. Production levels remain historically low, however, and many leases are thought to be underutilized. This study uses a novel approach leveraging high-resolution environmental data to evaluate lease utilization and identify constraints on aquaculture development. Stochastic Frontier Analysis (SFA) and Data Envelopment Analysis (DEA) were used to define environmentally-determined production frontiers, i.e. production possibilities based on empirical observations of aquaculture production, available space, and environmental conditions. Both methods estimated Lease Capacity Utilization (LCU, from 0 to 1) for leases producing …

Effects Of Climate Change On Metabolite Accumulation In Freshwater And Marine Cyanobacteria, I-Shuo Huang, Xinping Hu, Hussain Abdulla, Paul V. Zimba

VIMS Articles

Global climate change and anthropogenic nutrient inputs are responsible for increased frequency of cyanobac- terial blooms that potentially contain 55 classes of bioactive metabolites. This study investigated the effects of CO2 availability and concomittant pH levels on two cyanobacteria that produce microcystins: a marine cf. Syne- chocystis sp. and a freshwater Microcystis aeruginosa. Cyanobacterial strains were semi-continuously cultured in mesotrophic growth media at pH 7.5, 7.8, 8.2, and 8.5 via a combination of CO2 addition and control of alkalinity. The cell concentration between treatments was not significantly different and nutrient availability was not lim- ited. Concentration of most known cyanobacterial …

Krill Availability In Adjacent Adélie And Gentoo Penguin Foraging Regions Near Palmer Station, Antarctica, Schuyler C. Nardelli, Megan A. Cimino, John A. Conroy, William R. Fraser, Deborah K. Steinberg, Oscar Schofield

VIMS Articles

The Palmer Deep canyon along the West Antarctic Peninsula is a biological hotspot with abundant phytoplankton and krill supporting Adélie and gentoo penguin rookeries at the canyon head. Nearshore studies have focused on physical mechanisms driving primary production and penguin foraging, but less is known about finer-scale krill distribution and density. We designed two acoustic survey grids paired with conductivity–temperature–depth profiles within adjacent Adélie and gentoo penguin foraging regions near Palmer Station, Ant-arctica. The grids were sampled from January to March 2019 to assess variability in krill availability and associations with oceanographic properties. Krill density was similar in the two …

Asymmetric Root Distributions Reveal Press–Pulse Responses In Retreating Coastal Forests, Tyler C. Messerschmidt, Amy K. Langston, Matthew L. Kirwan

VIMS Articles

The impacts of climate change on ecosystems are manifested in how organisms respond to episodic and continuous stressors. The conversion of coastal forests to salt marshes represents a prominent example of ecosystem state change, driven by the continuous stress of sea-level rise (press), and episodic storms (pulse). Here, we measured the rooting dimension and fall direction of 143 windthrown eastern red cedar (Juniperus virginiana) trees in a rapidly retreating coastal forest in Chesapeake Bay (USA). We found that tree roots were distributed asymmetrically away from the leading edge of soil salinization and towards freshwater sources. The length, number, …

Evaluating Optimal Removal Of Derelict Blue Crab Pots In Virginia, Us, Andrew M. Scheld, Donna M. Bilkovic, Kirk J. Havens

VIMS Articles

Derelict fishing gear is a growing concern in many fisheries and coastal communities. Pots and traps are prevalent forms of derelict fishing gear with numerous documented harmful effects. In the Chesapeake Bay, US, a large blue crab (Callinectes sapidus) pot fishery produces high levels of derelict gear. From 2008 to 2014, 34,408 derelict pots were removed from blue crab fishing areas in Virginia. This research first evaluates whether observed increases in catch rates occurring contemporaneously with the removal program were the result of derelict gear removals. An econometric production model is then used to estimate marginal removal benefits …

Ciliate Microzooplankton From The Northeastern Gulf Of Mexico, Richard A. Snyder, Joseph A. Moss, Luciana Santoferrara, Marie Head, Wade H. Jeffrey

VIMS Articles

Microzooplankton mediate a critical juncture of autotrophic and heterotrophic microbial production in the water column. Taxonomic and ecological work on this group has been substantial, yet few reports exist for the offshore waters of the Gulf of Mexico (GOM). This report focuses on protists in the phylum Ciliophora collected at stations spanning the continental shelf in the northeastern GOM. We hypothesized that patterns of spatial distribution across the region would be west–east along the coast, rather than north–south coastal to offshore, reflecting major freshwater sources. Samples were obtained by 10 µm plankton net for microscopy and by filtration of seawater …

Comparison Of Nutrient Accrual In Constructed Living Shoreline And Natural Fringing Marshes, Randolph Chambers, A. L. Gorsky, Robert Isdell, Molly Mitchell, Donna Marie Bilkovic

Arts & Sciences Articles

Living shoreline marshes are coastal wetlands constructed as alternatives to “hardened shorelines” (e.g., bulkheads, riprap) to mitigate erosion and to allow for landward migration of intertidal habitat as sea level rises. Living shorelines are designed to mimic natural fringing marshes and over time should be sinks for carbon and other nutrients. We collected soil cores and aboveground plant material from 13 pairs of natural fringing marshes and living shoreline marshes of different ages and degree of isolation from more extensive marsh shorescapes to compare nutrient pools and accrual. Although the nutrient content of plants was similar within and between marsh …

Environmental Associations Of Cownose Ray (Rhinoptera Bonasus) Seasonal Presence Along The U.S. Atlantic Coast, Charles W. Bangley, Michelle L. Edwards, Claire Mueller, Robert A. Fisher, Et Al

VIMS Articles

Identifying the mechanistic drivers of migration can be crucial in shaping conservation and management policies. The cownose ray (Rhinoptera bonasus) is a relatively poorly understood elasmobranch species that occurs along the U.S. Atlantic coast and undergoes large-scale seasonal migrations. To better understand the drivers and timing of cownose ray seasonal migration in order to inform potential management measures, we analyzed telemetry detections of 51 mature cownose rays (38 female, 13 male) tagged with acoustic transmitters in the Maryland and Virginia portions of Chesapeake Bay. Detections within their summer habitat in Chesapeake Bay and winter habitat in the vicinity …

Penaeid Shrimp In Chesapeake Bay: Population Growth And Black Gill Disease Syndrome, Troy D. Tuckey, Jillian L. Swinford, Mary C. Fabrizio, Hamish J. Small, Jeffrey D. Shields

VIMS Articles

Since 1991, the number of penaeid shrimp occurring in Virginia waters of Chesapeake Bay has steadily increased, prompting an interest in developing a fishery. Although development of a shrimp fishery in the Chesapeake Bay region could bring economic benefits, the fishery may be hampered by the presence of a disease syndrome known as shrimp black gill (sBG). The objectives of our study were to (1) describe the spatial distribution and abundance patterns of shrimp in Chesapeake Bay, (2) relate relative abundance of shrimp to habitat characteristics, and (3) determine the presence and seasonality of sBG to better understand disease dynamics …