Life Sciences Commons^™

A Global Analysis Of Complexity–Biodiversity Relationships On Marine Artificial Structures, Elisabeth M. A. Strain, Peter D. Steinberg, Maria Vozzo, (...), Kathleen E. Knick, Rochelle D. Seitz, Et Al

VIMS Articles

Topographic complexity is widely accepted as a key driver of biodiversity, but at the patch-scale, complexity–biodiversity relationships may vary spatially and temporally according to the environmental stressors complexity mitigates, and the species richness and identity of potential colonists. Using a manipulative experiment, we assessed spatial variation in patch-scale effects of complexity on intertidal biodiversity.

Marine Harmful Algal Blooms (Habs) In The United States: History, Current Status And Future Trends, Donald M. Anderson, Elizabeth Fensin, Christopher J. Gobler, (...), Juliette L. Smith, Et Al

VIMS Articles

Harmful algal blooms (HABs) are diverse phenomena involving multiple. species and classes of algae that occupy a broad range of habitats from lakes to oceans and produce a multiplicity of toxins or bioactive compounds that impact many different resources. Here, a review of the status of this complex array of marine HAB problems in the U.S. is presented, providing historical information and trends as well as future perspectives. The study relies on thirty years (1990–2019) of data in HAEDAT - the IOC-ICES-PICES Harmful Algal Event database, but also includes many other reports. At a qualitative level, the U.S. national HAB …

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 …

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 …

Recruitment And Post-Settlement Mortality Of The Soft-Shell Clam, Mya Arenaria, Shantelle Landry

Dissertations, Theses, and Masters Projects

The soft-shell clam, Mya arenaria, is a benthic, filter-feeding, infaunal clam typically found in intertidal and shallow subtidal waters. Chesapeake Bay stocks of M. arenaria have been depleted since the 1960s due to various factors including predation, temperature, low recruitment, habitat loss, disease mortalities, and commercial harvest. As an important prey item for many commercial species, low abundances of these clams are mostly the result of the voracious appetite of the blue crab, Callinectes sapidus. In addition to predation, summer water temperatures in the Chesapeake Bay are likely driving the low abundances of M. arenaria, as water temperatures commonly surpass …

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 …

A Subtropical Nudibranch, Polycera Hummi (Abbott 1952), Described For The First Time From Virginia, Wissan A. Jawad, Stacy A. Kruger-Hadfield, Paige G. Ross

VIMS Articles

We collected an individual Polycera hummi, a subtropical nudibranch, in association with a green macroalga Ulva sp. from an intertidal oyster reef in Burtons Bay, Wachapreague, VA. The established range of P. hummi is based solely on a handful of records from Mississippi and Florida in the Gulf of Mexico and the Carolinas in the Atlantic Ocean. This finding marks the highest latitude that this species has been found, 350 km north of its previously established range from Mississippi to Beaufort, NC. We observed the individual actively navigate the Ulva thallus which had encrusting bryozoans (unidentified genus) and arborescent …

Cloud Shadows Drive Vertical Migrations Of Deep-Dwelling Marine Life, Melissa Omand, Deborah K. Steinberg, Karen Stamieszkin

VIMS Articles

Our study provides evidence that, in addition to diel vertical migration, zooplankton residing at >300-m depth during the day perform high-frequency, vertical migrations due to light modulation by clouds. Using a water-following framework and measurements and modeling of the twilight zone light field, we isolated the detailed phototactic response and show that some twilight zone animals are considerably more active than previously thought, with a cumulative distance traveled of more than one-third of that for diel migration. The increased movement increases predation risk and has implications for the metabolic requirements of these animals in the food-limited deep sea.

Seagrass Recovery Following Marine Heat Wave Influences Sediment Carbon Stocks, Lillian R. Aoki, Karen J. Mcglathery, Patricia L. Wiberg, Matthew P. J. Oreska, Amelie C. Berger, Peter Berg, Robert J. Orth

VIMS Articles

Worldwide, seagrass meadows accumulate significant stocks of organic carbon (C),known as “blue” carbon, which can remain buried for decades to centuries. However,when seagrass meadows are disturbed, these C stocks may be remineralized, leading to significant CO2 emissions. Increasing ocean temperatures, and increasing frequency and severity of heat waves, threaten seagrass meadows and their sediment blue C. To date, no study has directly measured the impact of seagrass declines from high temperatures on sediment C stocks. Here, we use a long-term record of sediment C stocks from a 7-km2, restored eelgrass (Zostera marina) meadow to show that seagrass dieback following a …

Toward A Better Understanding Of Fish‐Based Contribution To Ocean Carbon Flux, Grace K. Saba, Adrian B. Burd, John P. Dunne, (...), Deborah K. Steinberg, Et Al

VIMS Articles

Fishes are the dominant vertebrates in the ocean, yet we know little of their contribution to carbon export flux at regional to global scales. We synthesize the existing information on fish‐based carbon flux in coastal and pelagic waters, identify gaps and challenges in measuring this flux and approaches to address them, and recommend research priorities. Based on our synthesis of passive (fecal pellet sinking) and active (migratory) flux of fishes, we estimated that fishes contribute an average (± standard deviation) of about 16.1% (± 13%) to total carbon flux out of the euphotic zone. Using the mean value of model‐generated …

An Operational Overview Of The Export Processes In The Ocean From Remote Sensing (Exports) Northeast Pacific Field Deployment, David A. Siegel, Ivona Cetinic, (...), Deborah K. Steinberg, Et Al

VIMS Articles

The goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean Station Papa in the Northeast Pacific Ocean during summer of 2018, providing context for other papers in this special collection. The experiment was conducted with …

Fish Census: Monitoring Finfish Populations In Chesapeake Bay, Rachel Dixon

Reports

Grades: 9-12 Subjects: Life Science | Biology | Oceanography

In this activity, students will utilize data collected from a scientific survey to explore where different fishes live in a coastal estuary, and how their populations change over time.

Migrating To Motherhood: The Story Of Female Blue Crabs In Their Ecosystem, Alex Schnieder

Reports

Grades: 6-12 Subjects: Life Science

This lesson guides students through an investigation of the migratory patterns of blue crabs, their life stages, ecosystem use by life stage, harvest, and human impacts to their population.

Watercolors: Relating Properties Of Light To Organic Matter And Ecosystem Production, Derek Detweiler

Reports

Grades: 9-12 Subjects: Chemistry | Biology | Oceanography | Environmental Science

Using properties of light, students will determine the source and composition of dissolved organic matter in estuaries influenced by different land types its subsequent relationship with ecosystem production.

Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay Annual Progress Report: 2020-2021, Jack R. Buchanan, Mary C. Fabrizio, Troy D. Tuckey

Reports

No abstract provided.

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 …

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

Miscellaneous

No abstract provided.

Etiology In Action: Identifying Aquaculture Disease Threats Through Data Analysis, Malina Loeher

Reports

Grades: 9-12 Subjects: Biology | Environmental Science | Oceanography

How do scientists identify emerging disease threats? In this lesson, students will examine fish health, aquatic disease ecology, and aquaculture practices to answer this question.

Dial C For Collaboration: Finding Unknowns With Your Fellow Scientists, Brianna Stanley

Reports

Grades: 9-12 Subjects: Biology | Chemistry | Mathematics | Oceanography

In the sciences, collaboration is key. This exercise allows students to explore scientific collaboration and how to use "knowns" to measure an unknown using a linear equation.

Center For Coastal Resources Management Annual Report 2020, Center For Coastal Resources Management

Reports

No abstract provided.