University of Vermont

Rubenstein Ecosystem Science Laboratory

Rubenstein Lab research

Rubenstein Ecosystem Science Laboratory Research

Faculty associated with the Rubenstein Ecosystem Laboratory conduct research in disciplines ranging from ecological stoichiometry to apex predator ecology, in ecosystems ranging from Lake Champlain to Alaska. Below is a sampling of current faculty research programs. Learn more about the research of our undergraduate and graduate students:

Faculty Research Projects

Jason Stockwell

Population Structure in the Opossum Shrimp (Mysis diluviana)
Mysis is an important mid-trophic level omnivore that undergoes extensive diel vertical migrations (DVM). Undergraduate and graduate students are testing several hypotheses about how DVM may structure Mysis populations within lake systems, or alternatively, how Mysis population structure may influence their DVM behavior. We are using stable isotopes, fatty acids, and genetic markers to test for differences in phenotypic and genotypic traits within and among sites and across benthic and pelagic habitats within Lake Champlain.

Cyanobacteria Blooms Impacts on Fish and Food Webs
Cyanobacteria blooms are hypothesized to short circuit ecosystem function by interfering with energy transfer from primary producers to upper levels of food webs. Recent research suggests the lack of essential fatty acid (EFA) production by cyanobacteria may be the bottleneck, but most research has been limited to the phytoplankton-zooplankton trophic link. Undergraduate and graduate students are using field observations and laboratory experiments to test hypotheses about the link between cyanobacteria blooms and fish health and fitness. For example, does a negative relationship exist between the intensity of cyanobacteria blooms and EFA in fish? Do cyanobacteria blooms shift trophic pathways from “green” to “brown” food webs? What are the sub-lethal effects, if any, of cyanobacteria-based food webs on fish metabolism, and do these effects have long-term fitness consequences?

Aquatic Ecology Under the Ice
Our research on Lake Superior suggests lake whitefish build their lipid reserves during the winter, thanks to a diet of lipid-rich cisco eggs that incubate over winter. These results contradict conventional wisdom that winter is a time when fish deplete their reserves to “hang on” until spring arrives with warmer temperatures and new prey production. We are working with a local high school student to conduct feeding experiments to test if stable isotopes and fatty acid markers can be used to better trace food web dynamics under the ice.

Role of Disturbance on Phytoplankton Diversity
The intermediate disturbance hypothesis predicts that moderate levels of disturbance maximize local species diversity. We are working with colleagues within the Global Lake Ecology Observatory Network (GLEON) to test this hypothesis in two separate projects. In “Spring Blitz,” a team of undergraduate students are sampling a local pond to contribute to a standardized, global data set. The data set will be used to evaluate phytoplankton diversity as a function of spring thermal stratification, where development of the thermocline is used as the disturbance. In “Storm Blitz,” we are examining the impacts of storm events on phytoplankton diversity. This project is using long-term data sets to evaluate the relationship between changes in phytoplankton community composition and meteorological events.

William "Breck" Bowden

Arctic Long-Term Ecological Research program (ArcLTER)
The Arctic Long Term Ecological Research (ARC LTER) site is part of the Long-Term Ecological Research network of sites established by the National Science Foundation. Our research site is located in the foothills region of the Brooks Range, North Slope of Alaska (68° 38'N, 149° 43'W, elevation 760 m) and is based out of the University of Alaska's Toolik Field Station. The goal of Arctic LTER project is to understand changes in the Arctic system at catchment and landscape scales through knowledge of the linkages and interactions among ecosystems. To achieve this goal the Arctic LTER research group is studying the ecology of the surrounding tundra, streams, and lakes. This group consists of a large number of collaborating researchers from several institutions across the US. Our main objectives are to gain an understanding of the controls of arctic ecosystem structure and function through long-term monitoring and surveys of natural variation of ecosystem characteristics, through experimental manipulation of ecosystems over years and decades, and through synthesis of results and predictive modeling at ecosystem and watershed scales. Breck Bowden manages the Streams component of the Arctic LTER project with Bruce Peterson and Linda Deegan at the Ecosystems Center at the Marine Biological Laboratory in Woods Hole, MA and with Alex Huryn at the University of Alabama.

SCALER: Scale, Consumers and Lotic Ecosystem Rates
One of the pressing problems in stream ecology is to determine how results from small-scale ecological experiments can be used to understand the operation of entire ecological systems. The SCALER project will use cm- and reach-scale process measurements, consumer manipulation experiments, and stream network modeling to predict fundamental ecosystem characteristics of stream networks. The SCALER project is a continental scale experiment encompassing five biomes, each of which will have six sites with measurements nested at two scales (microhabitat, reach). Synoptic sampling will characterize watershed scale patterns. Rates of metabolism and nutrient uptake and responses to consumer exclusions will be measured at micro (0.1 m) and reach (100 m) scales. Diversity and ecosystem function will be linked at a basic level by comparing metabolism and nutrient dynamics with and without consumers larger than 0.5cm. Experimental results will be scaled with models. Coupling experiments and scaling exercises will characterize how plot-level experiments relate to patterns across larger scales such as landscapes (e.g., the stream network) and help understand the links between biodiversity and ecosystem function. The SCALER project is a collaborative effort among researchers at the University of Vermont, Kansas State University, the University of Kansas, the University of New Hampshire, Duke University, Southern Illinois University, the University of Georgia, Murray State University, and the University of Alaska at Fairbanks.

Northeast Water Resources Network (NEWRnet)
NEWRnet is a collaboration among the University of Vermont, the University of Delaware, and the University of Rhode Island to explore the use of advanced sensor network in watersheds to gather high-frequency, spatially-extensive water quality and quantity data for use in environmental management and and policy decision making. A fundamental part of the project is to employ experiments with volunteer stakeholders and to develop agent-based models to investigate how to align sensor data and their visualization with utilization by resource management and policy decision makers. Workforce development and diversity programs will be integrated into the research. Breck Bowden is co-leading the initiative to develop the advanced sensor network, with Dr. Andrew Schroth in the Department of Geology at the University of Vermont. Each of the collaborating states will deploy are series of cutting-edge water quality sensor systems in watersheds with distinctly different land-uses (forest, agriculture, and urban) to monitor long-term (annual) and event-based (storm) dynamics. Collectively, the sensors deployed by the three partners will provide a unique, region-wide sensor network that can provide near real-time feedback about large-scale weather phenomena.

EPSCoR Research on Adaptation to Climate Change (RACC)
The central question of this research project is “How will the interaction of climate change and land use alter hydrological processes and nutrient transport from the landscape, internal processing and eutrophic state within Lake Champlain and what are the implications for adaptive management strategies?” This research is organized around four supporting questions. First, what is the relative importance of endogenous in-lake processes (e.g. internal loading, ice cover, hydrodynamics) versus exogenous to-lake processes (e.g. land use change, snow/rain timing, storm frequency and intensity, land management) to lake eutrophication and algal blooms? This question broadens current research on the Lake Champlain Basin, by focusing on coupled human and natural system aspects. Second, which alternative stable states can emerge in the watershed and lake resulting from non-linear dynamics of climate drivers, lake basin processes, social behavior, and policy decisions? This question springs very directly from lessons learned by CSYS modelers of the Lake Champlain watershed data. Complex systems models will assist us in identifying the available stable states that lose resilience; recovery from some states (e.g. complete eutrophication) could be very difficult through land use management policies if they come to pass. Third, in the face of uncertainties about alternate climate change, land use and lake response scenarios, how can adaptive management interventions (e.g. regulation, incentives, treaties) be designed, valued and implemented in the multi-jurisdictional Lake Champlain Basin? Adaptive management on a local scale will be addressed through scenario testing and complex systems modeling, in particular agent-based models of policy actors. Breck Bowden’s role in this project is as a Senior Science advisor.

Ellen Marsden

Lake Trout
Lake trout populations disappeared from Lake Champlain by 1900 and the Great Lakes by 1960, due to overfishing and sea lamprey predation. Natural reproduction by stocked fish has been limited and is largely restricted to shallow, nearshore reefs, particularly man-made structures. My research focuses on the factors that affect lake trout survival between emergence from spawning reefs and the end of their first year of life.

  • Thiamine Deficiency in Lake Trout: Alewife invaded Lake Champlain in 2003 and pose a new threat to salmonids in Lake Champlain: alewife contain thiaminase, an enzyme that breaks down thiamine in their predators. When these species spawn, their eggs have insufficient thiamine, and the hatched fry exhibit behavioral and physical abnormalities known as Thiamine Deficiency Complex. We have been tracking the changes in egg thiamine levels since 2004 and are now examining the role of early feeding in restoring thiamine levels in wild fry.
  • Lake Trout Spawning Behavior: In collaboration with investigators in the Great Lakes, we are studying lake trout spawning behavior – what attracts them to a spawning site, how they select mates, diel changes in their behavior, and differences in male and female fidelity to spawning sites within and between spawning seasons. We are particularly interested in the possible use of pheromones, either emitted by males or left by earlier hatched fry, to identify good spawning sites. Tools for this work include underwater videography by divers and a small remotely operated underwater vehicle, tracking spawners within and between reefs using acoustic telemetry, and comparing behavior among systems.

Non-Chemical Control of Sea Lamprey
Sea lamprey is a nuisance species in the Great Lakes and Lake Champlain and is responsible for the decline of valuable commercial and recreational fisheries. Sea lamprey control is focused on the stream-resident larval stage, using chemical poisons, and at the spawning stage, using barriers and traps to prevent upstream migration of spawners. We are investigating the potential to also control lamprey at the transformer stage, when newly-metamorphosed parasites outmigrate from streams into lakes. Using a combination of stream trapping and behavioral work in the laboratory, we are learning where and when outmigration is focused – in what portions of the stream channel (deep or shallow, in the stream channel or near the banks), and when during the day and the season most movement occurs.

Microelemental Analysis of Sea Lamprey Statoliths
Chemical control of sea lamprey entails treating all streams with large populations of larvae using lampricides. Survival of larvae may not be equal from all streams; chemical use could be reduced by focusing treatments on streams that produce the most parasites. We are developing a method to identify the stream origins of parasitic sea lamprey to optimize choice of streams to treat with lampricides. Lamprey statoliths (ear-bones) acquire chemical elements in stream water during larval growth; using inductively-coupled plasma mass spectrophotometry (ICPMS) we can correctly classify larvae to their natal stream, but the metamorphosis of lamprey into parasites appears to alter the chemistry of the statolith, necessitating further work on understanding statolith microchemistry.

Habitat Restoration in Thunder Bay, Lake Huron
In the 1950s, over 80 acres of shoreline and submerged habitat near Alpena, MI, were degraded by inputs of lime kiln dust from a nearby industry. Valuable fish habitat, particularly spawning reef substrate, was lost due to covering and filling of interstitial space within the natural reef. This loss may be contributing to the lack of substantial progress toward restoration of self-sustaining lake trout populations. To remediate this damage, we constructed 27 artificial reefs in Thunder Bay in 2010 and 2011. The reef design allows testing of factors (reef orientation, height, and size) that attract spawning lake trout and lake whitefish and maximize egg and fry survival. The reefs also provide valuable foraging areas for walleye and basses. Project web site link.

Habitat Fragmentation in Lake Champlain
Since the early 1800s, Lake Champlain has been progressively fragmented by causeways that create virtually isolated bays (Inland Sea, Mallet’s Bay, Carry Bay, the Gut, northern section of the Northwest Arm). The effect of these divisions on fish movement is largely unstudied. Reduced connectivity between bays may have isolated populations of species such as smelt and lake whitefish. We are examining genetic differentiation among whitefish populations in the isolated basins of Lake Champlain, and using acoustic telemetry to track movement of lake whitefish and lake trout through causeway openings.

The Champlain Canal as an Exotic Species Vector
Currently, 49 non-indigenous species are established or present in Lake Champlain. Of those species for which the vector of introduction is known, 40% likely entered the lake via the Champlain Canal which links the lake to the Hudson River, Mohawk River, and Great Lakes drainages. We are focused on determining which taxa are most likely to use the canal as a vector in the future, and developing methods to prevent future invasions.

Last modified December 18 2014 11:38 AM