Cold Water Refugia

My postdoc research focuses on understanding the spatial pattern of water temperature across river networks under current and future conditions. This research has supported the US Environmental Protection Agency Cold Water Refuges Project and the Total Maximum Daily Load for Temperature in the Columbia and Lower Snake Rivers . The work uses a class of spatial statistical stream network (SSN) models to predict water temperature across the Pacific Northwest under a variety of scenarios (climate and restoration management options). These predictions help identify where cold-water habitat exists within networks and where tributaries enter the mainstem Columbia River to provide refuges from warm waters for migrating fishes. Additionally, these models are used to evaluate the impacts of management activities including riparian shade restoration, water use limitations, and channel geomorphology adjustments to find individual and cumulative effects of these interventions to protect cold-water habitat. Some of this research has already been published in Restoration Ecology and the Journal of Thermal Biology with other manuscripts currently in preparation for peer review.
Suites of SSN models use different combinations of covariates to fit observed temperature statistics.
Difference in August mean stream temperature predictions for current riparian vegetation reach shade vs restored riparian vegetation reach shade. 

Freshwater Habitat Fragmentation

My dissertation research focused on freshwater habitat fragmentation effects in river networks. To study these fragmentation effects on structural and functional connectivity, two approaches were used. First, simulation of freshwater mussel gene flow across the Neuse River basin in North Carolina, USA evaluated the known structural connectivity of the river network and life history strategies that might play a role in freshwater mussel response to fragmentation. Second, empirical measurement of freshwater mussel genetics (RADseq data) across the basin provided estimates of the functional connectivity within the river network. Dam removal is a major stream restoration tool and is increasing in prevalence across the United States as infrastructure continues to degrade and funding to repair aging dams is limited. This research can inform managers trying to identify locations for dam removal projects now as well as help develop plans for future removal sites. Gene flow simulation results from this research can be found in Conservation Genetics while other parts of the project are in preparation for peer review.
Collecting tissue from Elliptio complanata for genetic sequencing.
Deconstruction of the Lassiter Mill Dam on Uwharrie River in North Carolina.

Beaver Pond Morphology

Beaver pond morphology was evaluated as a predictor of downstream ecosystem change. This work was conducted at several beaver ponds in the Colorado Rocky Mountains while working from the Rocky Mountain Biological Laboratory. Beaver pond morphology was related to changes in individual mayfly fitness via water temperature and development timing mechanisms. Further investigations of the relationships between pond morphology and nutrient transport/limitation, algal accrual/standing stock, and invertebrate communities were also made at these sites. Results from this work can be found inFreshwater Biology and Hydrobiologia.
Collecting water samples from a beaver pond on Ceder Creek near RMBL.
Beaver pond site on Oh-Be-Joyful Creek outside Crested Butte, CO.

Aquatic-Terrestrial linkages (East African Stream Invertebrates!)

Land use and seasonality were evaluated for their influence on the communities of stream invertebrates in Tanzania's Gombe Stream National Park (GSNP) and its adjacent catchments. This project characterized and compared the communities of stream benthic invertebrates to see how seasonality and human land use alteration interact to alter stream invertebrate community composition.
​Sitting on Jane Goodale's porch.
Collecting invertebrate samples in GSNP.
Sorting an invertebrate sample in the field.

Bull Trout Reintroduction population demographics and genetics

I am currently working with a group simulating the reintroduction of bull trout to a tributary system within the Pend Oreille River network in northeastern Washington State. This work simulates bull trout population demographic and genetic consequences of reintroducing the endangered species into the system. Additionally, these simulations are being run across a suite of riverscape barrier scenarios where dams and/or culverts are being removed to try and understand the impact of complete and partial barriers on the trajectory of bull trout population stability and genetic population structure. Results for the initial model runs and scenarios are published in Ecosphere.
Sullivan Creek. One of the proposed reintroduction tributaries.
Mill Pond Dam. Proposed dam removal site on Sullivan Creek.