Publications

Vital rates such as mortality, growth, and recruitment are important tools to evaluate the status of threatened populations and identify their vulnerabilities, leading to enhanced conservation strategies. Native freshwater mussels are a guild of largely sedentary, filter-feeding bivalves currently facing worldwide declines. Lack of recruitment has been identified as a major threat to mussel popul

In this work, we hypothesize that phosphorus (P) concentrations in streams vary seasonally and with streamflow and that it is important to incorporate this variation when predicting changes in P loading associated with climate change. Our study area includes 14 watersheds with a range of land uses throughout the U.S. Great Lakes Basin. We develop annual seasonal load-discharge regression models fo

Observations of elemental mercury (Hg0) at sites in North America and Europe show large decreases (∼1–2% y−1) from 1990 to present. Observations in background northern hemisphere air, including Mauna Loa Observatory (Hawaii) and CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) aircraft flights, show weaker decreases (<1% y−1). These decrease

A groundwater-flow model was developed for the Bad River Watershed and surrounding area by using the U.S. Geological Survey (USGS) finite-difference code MODFLOW-NWT. The model simulates steady-state groundwater-flow and base flow in streams by using the streamflow routing (SFR) package. The objectives of this study were to: (1) develop an improved understanding of the groundwater-flow system in t

Birds can cause extensive crop damage in the United States. In some regions, depredating species comprise a substantial portion of the total avian population, emphasizing their importance both economically and ecologically. We used the National Audubon Society Christmas Bird Count data from the south-central United States and mixed-effects models to identify habitat factors associated with populat

Sources of mercury (Hg) in Great Lakes sediments were assessed with stable Hg isotope ratios using multicollector inductively coupled plasma mass spectrometry. An isotopic mixing model based on mass-dependent (MDF) and mass-independent fractionation (MIF) (δ202Hg and Δ199Hg) identified three primary Hg sources for sediments: atmospheric, industrial, and watershed-derived. Results indicate atmosphe

Region-specific conservation programs should have objective, reliable metrics for species prioritization and progress evaluation that are customizable to the goals of a program, easy to comprehend and communicate, and standardized across time. Regional programs may have vastly different goals, spatial coverage, or management agendas, and one-size-fits-all schemes may not always be the best approac

A collection of 24 datasets, including streamflow, well characteristics, groundwater elevations, and discrete water-quality concentrations, is provided to produce a consistent set of example data to demonstrate typical data manipulations or statistical analysis of hydrologic data. These example data are provided in an R package called smwrData. The data in the package have been collected by the U.

Conserving migratory birds is made especially difficult because of movement among spatially disparate locations across the annual cycle. In light of challenges presented by the scale and ecology of migratory birds, successful conservation requires integrating objectives, management, and monitoring across scales, from local management units to ecoregional and flyway administrative boundaries. We pr

There is growing need to develop models of spatial patterns in animal abundance, yet comparatively few examples of such models exist. This is especially true in situations where the abundance of one species may inhibit that of another, such as the intensively-farmed landscape of the Prairie Pothole Region (PPR) of the central United States, where waterfowl production is largely constrained by meso

Lake Erie is a large lake straddling the border of the U.S. and Canada that has become increasingly eutrophic in recent years. Eutrophication is particularly focused in the shallow western basin. The western basin of Lake Erie is hydrodynamically similar to a large estuary, with riverine inputs from the Detroit and Maumee Rivers mixing together and creating gradients in chemical and physical condi

Managers in the Upper Mississippi River (UMR) are using reductions in the River's water levels during summer to mimic historical water regimes and rehabilitate habitats for vegetation and other species. Concerns for the unintended effects of these actions on mussel populations threatened to halt these projects. Our objective was to characterise the survival and movement of two mussel species in t