Life Sciences Commons^™

Sequence Csi: The Nitrogen Cycle. Subjects: Life Science, Environmental Science, Marine/Ocean Science - Grades: 9-12, Stephanie Wilson

Reports

This lesson invites students to work together to identify a mystery DNA sample using state of the art biotechnology.

After identifying the organism, they can work with another group of students to hypothesize about how the different organisms are related to one another. Students will learn that the samples are connected through the nitrogen cycle! This gives students an introduction to scientific molecular techniques and environmental nitrogen cycling.

Investigating The Functions Of Wetlands, Chesapeake Bay National Estuarine Research Reserve In Virginia

Reports

Grade level: 2-5

Subject area: Life Science

Students will perform two experiments using models of wetlands to learn about the ability of wetlands to prevent erosion, control flooding, and soak up pollutants. They will apply this knowledge in an activity using metaphors to describe a wetland.There is also an outdoor activity that may be added to teach students about a particular type of wetland, the saltmarsh, and adaptations for plants that live in those environments

Long-Term Monitoring Of A Successful Recovery Program Of Peregrine Falcons In Virginia, B. D. Watts, Mitchell A. Byrd, E. K. Mojica, S. Padgett, S. R. Harding, C. A. Koppie

Arts & Sciences Articles

The Peregrine Falcon (Falco peregrinus anatum) was believed to be extirpated as a breeding species in Virginia by the early 1960s. An aggressive restoration program was initiated in 1978 that involved the release of captive-reared birds totaling 115 on the Coastal Plain (1978–1985) and 127 in the Mountain physiographic region (1985–1993). The first occupied territory was established and the first breeding attempt was documented in 1979 and 1982, respectively. We have monitored the size, distribution, reproductive rate, and substrate use of the resulting breeding population (1979–2016). The population proceeded through an establishment phase (1979–1993) driven by releases with an average …

Adaptations By Zostera Marina Dominated Seagrass Meadows In Response To Water Quality And Climate Forcing, Erin C. Shields, Ken Moore, David B. Parrish

VIMS Articles

Global assessments of seagrass declines have documented accelerating rates of loss due to anthropogenic sediment and nutrient loadings, resulting in poor water quality. More recently, global temperature increases have emerged as additional major stressors. Seagrass changes in the Chesapeake Bay, USA provide important examples of not only the effects of human disturbance and climate forcing on seagrass loss, but also meadow recovery and resiliency. In the York River sub-tributary of the Chesapeake Bay, the meadows have been monitored intensively using annual aerial imagery, monthly transect surveys, and continuous water quality measurements. Here, Zostera marina has been demonstrating a shift in …

Assessment Of Black Rail Status In Georgia, Interim Report: Summer 2018, B. D. Watts, B. J. Paxton, F. M. Smith

CCB Technical Reports

No abstract provided.

Predator-Induced Plasticity In Egg Capsule Deposition In The Mud Snail, Tritia Obsoleta, Emily A. Harmon, Jonathan D. Allen

Arts & Sciences Articles

Most marine invertebrates develop in the plankton, where microscopic offspring can avoid abundant benthic predators until settlement. However, at least four phyla of marine invertebrates (Annelida, Mollusca, Nemertea, and Platyhelminthes) deposit benthic egg capsules or masses. Often, these animals possess additional means to protect their young, including chemical or morphological defenses or nonrandom selection of deposition sites. Egg capsule deposition is the dominant reproductive strategy among gastropod molluscs, including the mud snail, Tritia obsoleta. In intertidal and shallow subtidal habitats in New England, the mud snail preferentially deposits egg capsules on blades of eelgrass (Zostera marina), a substrate that stands …

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.

Subgenome Dominance In An Interspecific Hybrid, Synthetic Allopolyploid, And A 140-Year-Old Naturally Established Neo-Allopolyploid Monkeyflower, Patrick P. Edger, Ronald Smith, Micheal R. Mckain, (...), Gregory D. Conradi Smith, Joshua R. Puzey

Arts & Sciences Articles

Recent studies have shown that one of the parental subgenomes in ancient polyploids is generally more dominant, having retained more genes and being more highly expressed, a phenomenon termed subgenome dominance. The genomic features that determine how quickly and which subgenome dominates within a newly formed polyploid remain poorly understood. To investigate the rate of emergence of subgenome dominance, we examined gene expression, gene methylation, and transposable element (TE) methylation in a natural, <140-year-old allopolyploid (Mimulus peregrinus), a resynthesized interspecies triploid hybrid (M. robertsii), a resynthesized allopolyploid (M. peregrinus), and progenitor species (M. guttatus …

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 …

Correlation Between Investment In Sexual Traits And Valve Sexual Dimorphism In Cyprideis Species (Ostracoda), Maria João Fernandes Martins, Gene Hunt, Rowan Lockwood, John P. Swaddle, David J. Horne

Arts & Sciences Articles

Assessing the long-term macroevolutionary consequences of sexual selection has been hampered by the difficulty of studying this process in the fossil record. Cytheroid ostracodes offer an excellent system to explore sexual selection in the fossil record because their readily fossilized carapaces are sexually dimorphic. Specifically, males are relatively more elongate than females in this superfamily. This sexual shape difference is thought to arise so that males carapaces can accommodate their very large copulatory apparatus, which can account for up to one-third of body volume. Here we test this widely held explanation for sexual dimorphism in cytheroid ostracodes by correlating investment …

Obligate Planktotrophy In The Götte's Larva Of Stylochus Ellipticus (Platyhelminthes), Jonathan D. Allen, A. M. L. Klompen, E. J. Alpert, A. J. Reft

Arts & Sciences Articles

Polyclad flatworms are a diverse and emerging model system for developmental biologists, yet development remains poorly understood for many species. One limitation of polyclads as a model system has been the lack of reliable methods for culturing planktotrophic polyclad larvae to metamorphosis. There are conflicting statements in the literature about which types of polyclad larvae require food to complete development. We developed simple methods for rearing planktotrophic flatworms to metamorphosis and tested the effects of food type and concentration on their development. The flatworm Stylochus ellipticus develops from small (~65 μm) eggs into an obligately planktotrophic Götte’s larva. In this …

Differential Effects Of Bivalves On Sediment Nitrogen Cycling In A Shallow Coastal Bay, Ashley Smyth, Anna E. Murphy, Iris C. Anderson, Bk Song

VIMS Articles

In coastal ecosystems, suspension-feeding bivalves can remove nitrogen though uptake and assimilation or enhanced denitrification. Bivalves may also retain nitrogen through increased mineralization and dissimilatory nitrate reduction to ammonium (DNRA). This study investigated the effects of oyster reefs and clam aquaculture on denitrification, DNRA, and nutrient fluxes (NOx, NH4 6 +, O2). Core incubations were conducted seasonally on sediments adjacent to restored oyster reefs (Crassostrea virginica), clam aquaculture beds (Mercenaria mercenaria) which contained live clams, and bare sediments from Smith Island Bay, Virginia, USA. Denitrification was significantly higher at oyster reef sediments and clam aquaculture site than bare sediment in …

Marine Parasites And Fish: How To Sample And Analyze. Subjects: Life Science / Biology, Environmental Science, Marine / Ocean Science Grades: 6-8, Zoemma Warshafsky

Reports

This lesson plan provides a hands-on way for students to investigate the impacts of an invasive parasitic nematode which has been targeting the American eel. Students will first “infect” pipe cleaner eels with parasitic nematodes (beads), which will then be used to simulate real-life research efforts through collecting multiple random samples of “eels” and counting the amount of parasites. They will then use this data to calculate prevalence, mean intensity, and mean abundance.

Digesting Data - Subjects: Life Science / Biology Grade Level: 6-8, Amanda Bromilow

Reports

This lesson plan encourages students to become scientific investigators to determine which fish species are important predators of juvenile blue crabs in Chesapeake Bay. Students will have the opportunity to practice using triple-beam balances and draw conclusions based on their data.

Counting Blue Crabs In The Bay! Subjects: Life Science / Biology, Environmental Science, Marine / Ocean Science Grade Level: 6-8, Bruce W. Pfirrmann

Reports

This lesson plan invites students and teachers to ponder the question: How many blue crabs are in the Chesapeake Bay, and where do we find them? Through hands-on activities and the use of real data, students will discover the excitement and grapple with the challenges faced by marine scientists as they try to quantify the use of different habitats by marine animals and estimate the size of marine animal populations.

Microscopic Hitchhiking: Taking A Trip With Microbes And Plankton. Subjects: Life Science / Biology, Environmental Science, Marine / Ocean Science Grades: 6-8, Lucia Safi

Reports

This lesson plan develops concepts on food webs and ecological relationships, giving special attention to microorganisms and Chesapeake Bay species and dynamics. Students will conduct investigations, generate their own data and find out more about species they constantly see!

The Effects Of Salinity And Ph On Fertilization, Early Development And Hatching In The Crown-Of-Thorns Seastar, Jonathan D. Allen, Kharis R. Schrage, Shawna A. Foo, Sue-Ann Watson, Maria Byrne

Arts & Sciences Articles

Understanding the influence of environmental factors on the development and dispersal of crown-of-thorns seastars is critical to predicting when and where outbreaks of these coral-eating seastars will occur. Outbreaks of the crown-of-thorns seastars are hypothesized to be driven by terrestrial runoff events that increase nutrients and the phytoplankton food for the larvae. In addition to increasing larval food supply, terrestrial runoff may also reduce salinity in the waters where seastars develop. We investigated the effects of reduced salinity on the fertilisation and early development of seastars, up to and including their hatching from the fertilisation envelope. We also tested the …

Utilization Probability Map For Migrating Bald Eagles In Northeastern North America: A Tool For Siting Wind Energy Facilities And Other Flight Hazards, Elizabeth K. Mojica, B. D. Watts, Courtney L. Turrin

Arts & Sciences Articles

Collisions with anthropogenic structures are a significant and well documented source of mortality for avian species worldwide. The bald eagle (Haliaeetus leucocephalus) is known to be vulnerable to collision with wind turbines and federal wind energy guidelines include an eagle risk assessment for new projects. To address the need for risk assessment, in this study, we 1) identified areas of northeastern North America utilized by migrating bald eagles, and 2) compared these with high wind-potential areas to identify potential risk of bald eagle collision with wind turbines. We captured and marked 17 resident and migrant bald eagles in the northern …

Nuclear Import Of The Thyroid Hormone Receptor Α1 Is Mediated By Importin 7, Importin Β1, And Adaptor Importin Α1, Vincent R. Roggero, Jibo Zhang, Laura E. Parente, Yazdi Doshi, Lizabeth A. Allison

Arts & Sciences Articles

The thyroid hormone receptor a1 (TRa1) is a nuclear receptor for thyroid hormone that shuttles rapidly between the nucleus and cytoplasm. Our prior studies showed that nuclear import of TRa1 is directed by two nuclear localization signals, one in the N-terminal A/B domain and the other in the hinge domain. Here, we showed using in vitro nuclear import assays that TRa1 nuclear localization is temperature and energy-dependent and can be reconstituted by the addition of cytosol. In HeLa cells expressing green fluorescent protein (GFP)-tagged TRa1, knockdown of importin 7, importin B1 and importin a1 by RNA interference, or treatment with …

Use Of Esi-Fticr-Ms To Characterize Dissolved Organic Matter In Headwater Streams Draining Forest-Dominated And Pasture-Dominated Watersheds, Randolph Chambers

Arts & Sciences Articles

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) has proven to be a powerful technique revealing complexity and diversity of natural DOM molecules, but its application to DOM analysis in grazing-impacted agricultural systems remains scarce. In the present study, we presented a case study of using ESI-FTICR-MS in analyzing DOM from four headwater streams draining forest- or pasture-dominated watersheds in Virginia, USA. In all samples, most formulas were CHO compounds (71.8–87.9%), with other molecular series (CHOS, CHON, CHONS, and CHOP (N, S)) accounting for only minor fractions. All samples were dominated by molecules falling in the lignin-like region …

Landfill Use By Bald Eagles In The Chesapeake Bay Region, Courtney Turrin, B. D. Watts, Elizabeth K. Mojica

Arts & Sciences Articles

We examined patterns in the use of landfills (rubbish dumps) in the Chesapeake Bay by Bald Eagles (Haliaeetus leucocephalus). Sites of solid waste landfills (n  =  72) were located using state databases. Satellite tracking data from 64 eagles were used to track eagle movements hourly during daylight and once at midnight to determine roosting locations (2007–2012). Landfill use varied significantly with age class, with hatch-year birds using landfills six times more often than adults and twice as often as third- and fourth-year birds. Hatch-year birds spent significantly more time at landfills than expected based on landfill area …

Seasonal Variation In Space Use By Nonbreeding Bald Eagles Within The Upper Chesapeake Bay, B. D. Watts, Elizabeth K. Mojica, B. J. Paxton

Arts & Sciences Articles

Access to food resources is essential to self-maintenance and reproduction and, for species of conservation concern, foraging areas are considered critical habitat. Human disturbance is an important factor restricting access to prey resources for Bald Eagles (Haliaeetus leucocephalus) and guidelines in the Chesapeake Bay have been developed to mitigate its impact. However, our ability to implement such guidelines has been limited by a lack of information on important foraging areas. We used Brownian bridge movement modeling to develop a population-wide utilization probability surface for Bald Eagles along shorelines within the upper Chesapeake Bay. We used locations (n …

Multiple Exportins Influence Thyroid Hormone Receptor Localization, Kelly Subramanian, Rose C. Dziedzic, Hallie N. Nelson, Mary E. Stern, Vincent R. Roggero, Cornelius Bondzi, Lizabeth A. Allison

Arts & Sciences Articles

The thyroid hormone receptor (TR) undergoes nucleocytoplasmic shuttling and regulates target genes involved in metabolism and development. Previously, we showed that TR follows a CRM1/calreticulinmediated nuclear export pathway. However, two lines of evidence suggest TR also follows another pathway: export is only partially blocked by leptomycin B (LMB), a CRM1-specific inhibitor; and we identified nuclear export signals in TR that are LMB-resistant. To determine whether other exportins are involved in TR shuttling, we used RNA interference and fluorescence recovery after photobleaching shuttling assays in transfected cells. Knockdown of exportins 4, 5, and 7 altered TR shuttling dynamics, and when exportins …

Nest Guarding In Chesapeake Bay Bald Eagles, Courtney Turrin, B. D. Watts

Arts & Sciences Articles

As Bald Eagle (Haliaeetus leucocephalus) populations approach carrying capacity in the Chesapeake Bay, competition for breeding territories appears to be intensifying. Frequent territorial interactions may force breeders to adjust nest-guarding behavior. We examined nest-guarding behaviors at active Bald Eagle nests in the lower Chesapeake Bay during the nesting season (2012 and 2013). Guarding coverage was 13.7 ± 4.2% of total observation time during the pre-laying period, 6.8 ± 2.2% of observation time in the incubation period, and 26.3 ± 3.2% of observation time in the nestling period. Females were present in the nest area for 80.0 ± 2.7% …

Intraspecific Intrusion At Bald Eagle Nests, Courtney Turrin, B. D. Watts

Arts & Sciences Articles

Competition for nesting territory has been shown to act as a density-dependent feedback mechanism influencing population growth rate. However, little is known about the nature of territorial interactions between established breeders and floaters. We examined territorial intrusion rates and associated behaviours at active Bald Eagle Haliaeetus leucocephalus nests in the lower Chesapeake Bay in 2012 and 2013. The average intrusion rate experienced at study nests during the reproductive period was 0.28 ± 0.32 intrusions/h. Variance in intrusion rate was high and there was no apparent predictive pattern to these events. Juvenile intrusions occurred closer to the nest than adult intrusions, …

Stormwater Runoff Drives Viral Community Composition Changes In Inland Freshwaters, Randolph Chambers

Arts & Sciences Articles

Storm events impact freshwater microbial communities by transporting terrestrial viruses and other microbes to freshwater systems, and by potentially resuspending microbes from bottom sediments. The magnitude of these impacts on freshwater ecosystems is unknown and largely unexplored. Field studies carried out at two discrete sites in coastal Virginia (USA) were used to characterize the viral load carried by runoff and to test the hypothesis that terrestrial viruses introduced through stormwater runoff change the composition of freshwater microbial communities. Field data gathered from an agricultural watershed indicated that primary runoff can contain viral densities approximating those of receiving waters. Furthermore, viruses …

The Influence Of Recreational Crabbing Regulations On Diamondback Terrapin By-Catch, Randolph Chambers

Arts & Sciences Articles

Malaclemys terrapin terrapin (Northern Diamondback Terrapin) is susceptible to drowning in commercial-style pots used for the Callinectes sapidus (Blue Crab) fishery. Regulations to reduce by-catch mortality vary by state. We compared three different regulatory strategies with respect to crab catch and their relative effectiveness at reducing terrapin by-catch. To mimic their possible use by recreational crabbers, we grouped and fished together ten unbaited crab pots with no by-catch reduction devices (BRDs), ten with large BRDs, and ten with small BRDs in a tidal creek in southeastern Virginia. Over 24 sampling days, the total legal crab catch (crabs ≥ 12.7 cm) …

Recovery Of Breeding Bald Eagles On Aberdeen Proving Ground, B. D. Watts

Arts & Sciences Articles

We conducted annual aerial surveys (1991-2011) for breeding Bald Eagles (Haliaeetus leucocephalus) within Aberdeen Proving Ground (APG), a 350-km2 military installation located along the northwestern shoreline of the upper Chesapeake Bay in Maryland. The population increased exponentially from 1 pair in 1977 to 58 pairs in 2011 with an average doubling time of 5.8 years. This rate was higher than that documented for the broader Chesapeake Bay and is comparable to the highest reported throughout the species range. Annual population increase was highly variable and exhibited no indication of any systematic decline. A total of 646 chicks were produced from …

Occurrence And Distribution Of The Freshwater Amphipodsgammarus Pseudolimnaeus And Gammarus Fasciatus Insoutheastern Virginia, Randolph Chambers

Arts & Sciences Articles

The freshwater amphipod, Gammarus fasciatus, and a population that keys to Gammarus pseudolimnaeusare broadly sympatric in southeastern Virginia. By documenting the successful formation of pre-copulatory mate-guarding pairs between individuals collected from Virginia and New York, we confirmed the occurrence of a G. pseudolimnaeus population strongly disjunct from the previously described range in the Mississippi and St. Lawrence River drainage basins. Gammarus pseudolimnaeus appears restricted to high-quality, spring-fed streams that occur at low density across an increasingly fragmented natural landscape in Virginia. Gammarus fasciatus, however, occurs in lakes and streams of developed landscapes that typically are more degraded, …

Dissolved And Particulate Organic Carbon Fluxes From An Agricultural Watershed During Consecutive Tropical Storms, Randolph Chambers

Arts & Sciences Articles

Low‐frequency high‐magnitude hydrologic events mobilize a disproportionate amount of dissolved organic carbon (DOC) from watersheds, but few studies measure the role of extreme storms in exporting organic carbon from croplands. We use high‐resolution measurements of storm runoff to quantify DOC and particulate organic carbon (POC) fluxes from an agricultural field during consecutive tropical storms that delivered 41 cm of rainfall to the Virginia Coastal Plain. Over a 2 week period, we measured exports of 22 kg DOC ha−1 and 11.3 kg POC ha−1. Ultraviolet absorbance measurements indicate that the aromatic DOC fraction systematically increased as plant‐derived aliphatic carbon was depleted …