Staff research
Sources of Suspended Sediment in Minnesota’s Rivers
A series of projects is examining the sources of suspended sediment to rivers and streams in Minnesota’s agricultural areas. Current projects involve studies of Lake Pepin on the Mississippi River, the South Fork of the Crow River, and Redwood and Seven Mile Creeks, and other tributaries to the Minnesota River. These projects use atmospherically-deposited radio isotypes to fingerprint eroding sediment sources, and compare these fingerprints to suspended sediments in rivers and lakes. Funded by and in collaboration with Minnesota Pollution Control Agency.
Watershed outlet monitoring program—Valley Creek
Streams are sensitive to land-use changes in their watersheds, and urbanization is a land-use change affecting nearly all streams in the Twin Cities metropolitan area. Because one of the responsibilities of the Metropolitan Council Environmental Services (MCES) is to develop target pollution loads for all Metropolitan Area watersheds, MCES has established the Watershed Outlet Monitoring Program (WOMP) to monitor loads of common pollutants such as suspended sediment, nitrogen, and phosphorus, among others. The project is intended to run for many years and generate long-term sets of water-quality data to better understand the effects of land-use change on these watersheds. Valley Creek is an important watershed in the monitoring network because it may serve as a relatively pristine end-member, a standard of comparison for the other, more urban-impacted streams.
The Diatoms, Ostracodes, and Chironomids of Western Mongolia's saline lakes: biodiversity, ecology, and research applications
Sixty lakes in Mongolia's Valley of the Great Lakes that span gradients from fresh to hypersaline and brine types will be sampled for modern diatom, chironomid, and ostracode assemblages. Diatom and ostracode calibration sets will be prepared for future paleosalinity and paleoclimatic applications. Subsets of collections will be accessioned in curated collections in museums in Mongolia (NUM), America (SMM and UMinn), and Belgium (RBINS). The success and approach of the PRAIRIE research group will be further applied to mid-Asia's large closed basin region to decipher paleoclimatic records in this climatically responsive region. Funded by the National Science Foundation-Biodiversity Surveys and Inventories. Collaborators: University of Minnesota (Entomology, Geology), Royal Belgian Institute of Natural Sciences, National University of Mongolia, Mongolian Academy of Sciences (Paleontology), St. Olaf College.
Long-term impacts of lake-level alterations on water quality in Voyageurs National Park
The natural water levels of the large lakes in Voyageurs National Park - Rainy, Kabetogama, Namakan - have been altered and artificially manipulated for almost a century by a series of dams built to serve the logging industry. This project is exploring the biological consequences of lake-level changes through the analysis of fossil diatoms in dated lake-sediment cores. Multivariate numerical techniques including correspondence analysis and ordination along with environmental reconstruction based on a modern diatom/water-quality data set from Minnesota lakes will be used to rigorously evaluate limnological trends. Funded by USGS-NRPP program. Collaborators: National Park Service, U.S. Geological Survey, University of Minnesota (graduate student).
Using wetland environmental histories to develop management strategies for the St. Croix Riverway
Floodplains are a dominant feature in the Lower St. Croix National Scenic Riverway. Braided channels and wetlands harbor high diversity of plants and wildlife and are crucial nesting and nursery areas. Recreational uses include wildlife watching, fishing, and hunting. Floodplains are a crucial component in preventing unnatural water quality degradation, maintaining natural patterns and amounts of flow, and maintaining native organisms and their habitats. However, historical data indicate that floodplain wetlands have undergone significant changes possibly from exotic species introductions, land use changes in the watershed, and river management. This project will recover sediment cores from three floodplain wetlands in the Lower St. Croix River, analyze them to reconstruct the ecological history from geochemical and biological markers, and form a baseline for making management decisions regarding wetland protection and restoration. Funded by USGS-NRPP.
Protecting and propagating the genetic diversity of the Lower St. Croix Watershed through reconstruction of a 32 acre prairie on an abandoned agricultural field
A 32 acre site will be restored to prairie using St. Croix Ecotype seed. The site is divided into 17 separate plantings, testing methods to maximize floristic diversity. Variables include four seeding densities, two grass:forb ratios, and spring vs. fall planting (plus 1 control plot). Once established the restoration can be used as a site to examine the effect of floristic diversity on habitat value. Funded by National Park Service.
Biomonitoring prospects for diatoms and paleolimnology in the Western Great Lakes National Parks
In Great Lakes Network (GLKN) National Park units, climate change, environmental contaminants, exotics, and land and resource uses including shoreline and urban development, recreation, water level management, logging, and agriculture have raised concerns about the state of the parks' resources and how to best manage them in a future certain to bring change. In this project we developed a strategy to integrate the use of paleolimnological techniques and diatom analysis in an inventory and monitoring framework. Results will provide a management foundation by determining the natural variability or reference condition of national park lakes. Because lake-sediment records integrate across both spatial and temporal scales, research results will be further used as a biomonitoring strategy by revisiting lakes on regular intervals (3-5 years) to quantify modern environmental conditions relative to historical conditions, to detect early ecological change and recent trends, and to evaluate success of management actions. Funded by National Park Service-GLKN. Collaborators: National Park Service
St. Croix Greenway sand prairie reconstruction: maximizing floristic diversity
Project will reconstruct 4 acres of prairie incorporating over 70 local ecotype plant species, designed to re-establish a stepping stone of high quality grassland wildlife habitat within the 4-mile St. Croix Greenway Corridor. Simultaneously, the project will be implemented using a suite of planting techniques that can subsequently be assessed to determine which methods create the maximum floristic diversity for the least amount of cost. Funded by MN DNR.
Manage nonpoint pollutants by watershed modeling of targeted subwatersheds in the St. Croix National Scenic Riverway
Construct computer watershed models of the Willow River in western Wisconsin and the Sunrise River in eastern Minnesota. The models will be applied to test the effectiveness of selected land-management scenarios in reducing the sediment and phosphorus loads from these watersheds into the St. Croix River. Funded by National Park Service.
Monitoring water quality in wadeable streams of national park units of the Great Lakes Inventory and Monitoring Network
The objective of this project is to develop a protocol for monitoring water quality in wadeable streams that will be consistent with and complement the protocols for lakes and large rivers. In addition to chemical and physical parameters, biota may be included in this protocol. Funded by National Park Service/CESU.
Recently Completed Projects
Enhanced rates of mercury methylation from sulfate deposition: a whole wetland experiment
This study explores the impact of increased atmospheric sulfate deposition on methylmercury (MeHG) production and transport from forested wetlands in northern Minnesota. The primary objective of this study is to conduct a whole wetland sulfate-addition experiment to elucidate methylation enhancing processes. The study builds on a recently concluded investigation funded by the EPA STAR program. The STAR project established a whole-wetland irrigation system for amending sulfate deposition through simulated rainfall. Two years of experimental additions provide evidence that sulfate additions at near ambient-strength can substantially increase MeHg production at the watershed scale. This proposal extends the experimental sulfate additions for two additional years. Funded by EPA, Great Lakes Atmospheric Deposition Program.
Natural and anthropogenic sources of mercury to the atmosphere: global and regional contributions
This project will address questions relating to natural and anthropogenic contributions from global and localized sources, the identification of Hg deposition with a United States origin (i.e., potential to affect sensitive ecosystems), and the examination of spatial and temporal trends (e.g., increases, declines) in atmospheric Hg deposition for future and past predictive/modeling purposes. This research is focused on current measurement, reconstruction, quantification, and interpretation of the modern and historical variation in atmospheric Hg fluxes associated with the mid and sub-tropical latitudes of North America. Funded by Environmental Protection Agency.
SW and central Minnesota Lakes: expanding the Minnesota diatom training set and developing nutrient criteria
Twenty-four lakes in SW Minnesota and 28 lakes in central Minnesota were monitored for a suite of environmental variables by the Minnesota Pollution Control Agency during 2002-2004. Surface sediment samples from this same set of lakes were analyzed for diatom remains to expand the 55-lake diatom calibration set for Minnesota to be more applicable for environmental reconstructions across more lake types and a wider range of total phosphorus. A subset of these lakes was cored and their pre-settlement and post-settlement nutrient conditions reconstructed from the diatom remains. These data served to develop regional trends in lake water quality and statewide nutrient criteria. Funded by the Minnesota Pollution Control Agency. Collaborators: University of Minnesota-NRRI, Minnesota Pollution Control Agency.
Application of computer modeling to the Willow River watershed to assess effectiveness of proposed mitigation strategies
Construct computer watershed models of the Willow River in western Wisconsin. The model will be applied to test the effectiveness of selected land-management scenarios in reducing the sediment and phosphorus loads from this watershed to the St. Croix River. Funded by WI DNR. Collaborator: University of Minnesota (graduate student).
St. Croix Greenway prairies: a research approach to reconstructions
This project will reconstruct 12 acres of prairie and prepare an additional 7 acres, using 52 species at two separate abandoned agricultural fields within the St. Croix Greenway Corridor. When complete, these plantings will serve as both highly diverse, local ecotype prairie reconstructions, and as scientific research sites to evaluate methods to maximize floristic diversity. Terrace Gateway will be restored in 4 quadrants testing patch seeding versus uniform seeding. Pitcher Field will be replanted as a series of identical 1 acre plots. Using the same seed mix annually, one acre will planted each year for 10 years, thus examining the temporal dynamics and maturation of diversity and species composition. Funded by MN DNR-Metro Corridors.
A pilot study to separate contributions of upland erosion from bank erosion to suspended sediment in the Minnesota River
A pilot study to separate sources to suspended sediment in the Minnesota River using a new technique with atmospherically-deposited radio isotopes. Funded by and in collaboration with Minnesota Pollution Control Agency.
Diatom-based phosphorus reconstructions on sediment cores from lakes in the Minnehaha Creek Watershed District
The Minnehaha Creek Watershed District (MCWD) extends from the Lake Minnetonka watershed to the mouth of Minnehaha Creek as it enters the Mississippi River. The lakes in the MCWD and the bays of larger Lake Minnetonka show a wide range of modern water quality conditions. Efforts to develop water quality management strategies in the MCWD hinge on understanding background or natural conditions of these water bodies. To this end, project objectives are: (1) to perform diatom-inferred top-bottom reconstructions of historical total phosphorus on 10 sediment cores collected from lakes in the Minnehaha Creek Watershed District (MCWD), and (2) to append diatom assemblages from surficial sediments and modern environmental data onto the existing Minnesota diatom calibration set to increase its applicability and predictive power in the MCWD. Funded by MCWD.
Analysis of water quality trends and current conditions in Mississippi River National River and Recreation Area
The principal investigators will analyze water quality data to provide an improved understanding of current water quality conditions and recent water quality trends throughout MNRRA. Included will be assessment of current conditions and analysis of 30-year trends at seven sites on the Mississippi River, determination of downstream spatial trends in water quality, and calculation of loads at three sites where adequate flow data exists. Funded by National Park Service/CESU.
Establishing sites for monitoring water quality on large rivers
Long-term monitoring of river water quality requires an understanding and analysis of river discharge. The objective of this project is to expand on the existing USGS stream-gaging network and establish water discharge rating curves at sites that are necessary for implementing the large rivers monitoring protocol.
Funded by National Park Service/CESU
Mercury Contamination and Biogeochemical Cycling in the Arctic
Limited knowledge exists concerning either the atmospheric, terrestrial, and marine cycling of Hg in polar regions or the impact from pollution-derived Hg at high latitudes. This research in the U.S. Arctic focused on (a) atmospheric Hg deposition and contamination of lakes and watersheds and (b) in-lake cycling (i.e. Hgo production and Hg methylation) and water-air exchange of Hg. The 3-year study was conducted in the terrestrial and lacustrine environs near the Arctic LTER Site at Toolik Field Station. Funded by the National Science Foundation.
Collaborators: University of Connecticut
Reconstruction of Trophic Change in the Carnelian-Marine Watershed District
The objective of this study was to document through paleolimnological methods, historic changes in trophic conditions in four lakes located within the Carnelian-Marine Watershed District, Washington Co, Minnesota. Funded by the Carnelian-Marine Watershed District.
Collaborators: University of Nebraska
