Faculty and graduate students 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.

Arctic Long-Term Ecological Research (ArcLTER)

Alaska tundra and mountains

Faculty: William "Breck" Bowden

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 and is based out of the University of Alaska's Toolik Field Station. The goal of Arctic LTER is to understand changes in the Arctic system at catchment and landscape scales by studying the ecology of the surrounding tundra, streams, and lakes. Our main objectives are to understand 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. 

Carbon Concentrating Mechanisms & Harmful Blooms

Microcystis

Faculty: Morales-Williams Limnology Lab

Harmful blooms are increasing in frequency and intensity worldwide. These trends are attributable to a perfect storm of climate change processes, land use alteration, and nutrient inputs. Clear links exist between ambient nutrient concentrations and bloom occurrence, but drivers of the specific timing and duration of these events remain unresolved. Several groups of phytoplankton including cyanobacteria are able to actively transport bicarbonate across their cell membrane when CO2 concentrations are limiting. This may provide a competitive advantage maintaining bloom biomass when CO2 is depleted. Using stable carbon isotope analysis in 16 agriculturally eutrophic lakes, we found that CCMs appear to be triggered when water column CO2 drops below atmospheric equilibrium.  This mechanism not only maintains bloom biomass, but appears to sustain an influx of atmospheric CO2 to lake surface waters.

Cyanobacteria & Food Webs

Hand holding blue green algae

Faculty: Jason Stockwell

Cyanobacteria blooms have negative impacts on humans, and climate change is expected to exacerbate blooms. For instance, cyanobacteria are the aquatic equivalent of junk food, and are hypothesized to short circuit ecosystems by interfering with energy transfer from primary producers to upper levels of food webs. They can also produce toxins linked to liver cancer and are hypothesized to be associated with neurodegenerative diseases such as ALS. Our research examines the extent to which cyanobacteria blooms can be detrimental to the health of food webs, in particular fish, and ultimately to humans who eat the fish.

Effects of Eutrophication on Lake Carbon Cycling

Buoy on lake

Faculty: Morales-Williams Limnology Lab

Lakes are generally considered net sources of carbon dioxide to the atmosphere, but only a handful of studies have investigated CO2 flux in eutrophic and hypereutrophic lakes with autochthonous organic carbon pools. Using a combination of high frequency sensor measurements and optical organic matter characterization, we investigate the source and magnitude of inorganic carbon flux across trophic gradients. As more lakes become impacted by expanding agriculture and urbanization, understanding how eutrophic systems process, store, and export carbon will be critical to evaluating the role of lakes in global carbon cycles.

EPSCoR Research on Adaptation to Climate Change (RACC)

Lake Champlain

Faculty: William "Breck" Bowden

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?” The project will investigate the relative importance of endogenous in-lake processes versus exogenous to-lake processes to lake eutrophication and algal blooms, and determine whether alternative stable states can emerge in the watershed and lake. Adaptive management on a local scale will be addressed through scenario testing and complex systems modeling, in particular agent-based models of policy actors.

Implications of Climate Change on Large Lakes

Researcher with equipment on boat on lake

Faculty: Jason Stockwell

A growing body of evidence suggests that the Earth’s climate is changing in a significant way.  How large-lake ecosystems respond to climate change is a growing area of concern because of the many services these systems provide. We are using a combination of lab experiments, field sampling, and modeling to explore how environmental variability and climate change are likely to influence recruitment bottlenecks within cold-water fish populations, such as cisco, in the Great Lakes. Cisco and other related Coregonid species worldwide have experienced population declines due to fishing pressure and environmental changes that appear to have reduced recruitment. Understanding how organisms will adapt to climate change is critical for management agencies to maintain diverse, abundant, and healthy populations of native species.

Lake Trout Restoration & Thiamine Deficiency

Lake trout under water

Faculty: Ellen Marsden

The invasion of alewife in 2003 poses a new threat to lake trout and Atlantic salmon in Lake Champlain: alewife contain thiaminase, an enzyme that breaks down thiamine in their predators. Severe thiamine deficiency in hatchery fry causes physical and behavioral symptoms, and high mortality. We are examining whether early foraging in wild lake trout fry could restore thiamine.

Lake Trout Spawning Behavior

Research holding large trout

Faculty: Ellen Marsden

Working with Great Lakes colleagues, we are studying lake trout spawning: how they select mates, how behavior changes from daytime to nighttime, when spawning occurs, and whether sexes differ in their movement among spawning sites within and between years. We have established an acoustic telemetry array throughout Lake Champlain, and tagged 30 lake trout in 2013 to follow their movements year-round. We are also observing behavior on a single reef using a home-built remotely-operated vehicle.

Linking Biodiversity Across Ecosystem Boundaries

Cedar Bog

Faculty: Morales-Williams Limnology Lab

Terrestrial ecosystems are rapidly changing to meet the food and energy demands of a large and growing human population. Nearly half of the global terrestrial landscape is dedicated to agriculture and urban areas, contributing to biodiversity loss and alterations to global biogeochemical cycles. This simplification of our landscapes alters the quality and quantity of exported carbon and nutrients. Resultant shifts in the composition of these subsidies can affect community structure and the functional diversity of downstream aquatic ecosystems. In collaboration with Jim Cotner and Cody Sheik at the University of Minnesota, we investigate the effects of terrestrial biodiversity loss and chemical diversity of exported subsidies on downstream biodiversity and function of microbial communities.

Mysis Ecology

Shrimp-like Mysis

Faculty: Jason Stockwell

Mysids are a group of omnivorous “shrimp-like” invertebrates found in freshwater and marine environments. They exhibit diel vertical migration and play a critical role in food webs because they link benthic and pelagic habitats and communities. We study the behavior, ecology, and population structure of this important species using traditional and cutting-edge techniques including an autonomous video camera system, fatty acids, and stable isotopes. A central focus of our research is to evaluate individual variability in migration, or in other words – why do some migrate vertically while others do not.

Northeast Water Resources Network (NEWRnet)

flooded road in a town

Faculty: William "Breck" Bowden

NEWRnet explores 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 policy decision making. Each of the collaborating states will deploy a 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.

SCALER: Scale, Consumers & Lotic Ecosystem Rates

Researcher in stream with equipment

Faculty: William "Breck" Bowden

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. 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.

Storm Impacts on Lakes

Lake flooding shore parking lot

Faculty: Jason Stockwell

Storms can physically alter lake environments and thus are capable of altering primary producers, including the development of toxic cyanobacterial blooms and other lake processes that depend upon phytoplankton communities. The effects of storms, however, may be dependent on local features such as lake size and morphometry, productivity and watershed area. Because storm intensities and frequencies are expected to increase under climate change, how lakes respond to such disturbances is a growing area of concern - aquatic ecosystems are increasingly recognized for the services they provide, such as public and environmental health, recreation, and industry. We are working with an international team to examine the potential for storms to alter phytoplankton diversity and composition across a gradient of lake types and to explore the potential impact of these changes on ecosystem functions.

Winter Limnology

Researcher on frozen lake

Faculty: Jason Stockwell

As precipitation patterns are altered and temperatures increase with climate change, temperate lakes may experience decreased snow cover and subsequent increased light penetration, as well as decreased ice cover. These changes may lead to higher inoculum concentrations of some phytoplankton groups (e.g. cyanobacteria) as they emerge from winter, potentially leading to higher magnitude or frequency of harmful algal blooms later in the year. We use a combination of lab work, field experiments, and quantitative methods to explore these hypotheses related to how winter severity influences plankton communities throughout the year.