Publications

The North Atlantic Current (NAC) transports warm salty water to high northern latitudes, with important repercussions for ocean circulation and global climate. A southward displacement of the NAC and Subarctic Front, which separate subpolar and subtropical water masses, is widely suggested for the Last Glacial Maximum (LGM) and may have acted as a positive feedback in glacial expansion...

The Great Dismal Swamp National Wildlife Refuge (GDS) is a forested peatland that provides a number of ecosystem services including carbon (C) sequestration. We modeled and analyzed the potential capacity of the GDS to sequester C under four management scenarios: no management, no management with catastrophic fire, current management, and increased management. The analysis uses the Land...

Managers, policy makers, and decision makers with responsibility for environmental decisions have an extraordinarily difficult job. The systems they manage are complex (coupled human-natural systems), with many dimensions and complicated dynamics. Our knowledge of how those systems respond to management actions is often limited, so many of the decisions have to be made in the face of...

In capture-mark-reencounter studies, Pollock’s robust design combines methods for open populations with methods for closed populations. Open population features of the robust design allow for estimation of rates of death or permanent emigration, and closed population features enhance estimation of population sizes. We describe a similar design, but for use with removal data. Data...

Candy Darters (Etheostoma osburni) and Variegate Darters (E. variatum) are both native to West Virginia and Virginia. The geographic ranges of these two species were historically separated by Kanawha Falls, a natural barrier to fish dispersal located at Glen Ferris, WV. In the early 1980s, Variegate Darters or putative hybrids (E. osburni × E. variatum) were first collected at locations...

A primary goal for Chesapeake Bay watershed restoration is to improve stream health and function in 10% of stream miles by 2025. Predictive spatial modeling of stream conditions, when accurate, is one method to fill gaps in monitoring coverage and estimate baseline conditions for restoration goals. Predictive modeling can also monitor progress as additional data become available. We...

Whooping cranes (Grus americana) are 1 of the most endangered bird species in North America. In 1999 the Whooping Crane Eastern Partnership was formed to establish a migratory population of whooping cranes in eastern North America. These efforts have been extremely successful in terms of adult survival but reproductive success post-release has been low. One hypothesis developed to...

Many waterbird populations have faced declines over the last century, including the common tern (Sterna hirundo), a waterbird species with a widespread breeding distribution, that has been recently listed as endangered in some habitats of its range. Waterbird monitoring programs exist to track populations through time; however, some of the more intensive approaches require entering...

Downstream migrating anguillid eels face many barriers including turbines and pumps at impoundments for water abstraction, power generation and water level control, when attempting to exit the freshwater catchment to reach spawning grounds. Multiple eel species worldwide are facing different levels of endangerment and alleviating the impacts of barriers to migration is essential to allow

In the western U.S., produced water from oil and gas wells discharged to surface water augments downstream supplies used for irrigation and livestock watering. Here we investigate six permitted discharges on three neighboring tributary systems in Wyoming. During 2013-16, we evaluated radium activities of the permitted discharges and the potential for radium accumulation in associated...

The northern diamondback terrapin (Malaclemys terrapin terrapin) is a saltmarsh-dependent turtle that occupies coastal habitats throughout much of the Atlantic coast of North America. We used a novel application of acoustic telemetry to quantify both mobility and occupancy of terrapins within a dredged harbor and surrounding habitats, and used these metrics to quantify relative risk to...

The late Eocene Chesapeake Bay impact structure was formed in a multilayered target of seawater underlain sequentially by a sediment layer and a rock layer in a continental-shelf environment. Impact effects in the “brim” (annular trough) surrounding and adjacent to the transient crater, between the transient crater rim and the outer margin, primarily were limited to the target-sediment...