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Rick Relyea

Director, Darrin Fresh Water Institute; Director, Jefferson Project; & David M. Darrin ’40 Senior Endowed Chair | Biological Sciences

Troy, NY, UNITED STATES, Jonsson-Rowland Science Center, 1W14

Researches community ecology, ecotoxicology, phenotypic plasticity, forest inputs to wetlands, disease ecology, and invasive species

Areas of Expertise

Aquatic BiologyAnimal BehaviorEvolutionEnvironmental ScienceEcologyEcotoxicologyLimnologyDisease Ecology


Dr. Relyea completed his PhD at the University of Michigan in 1999 and then spent the next 15 years as a professor at the University of Pittsburgh, where he also served as the director of the Pitt field station, The Pymatuning Lab of Ecology. In 2014, he moved his research group to Rensselaer to become the Director of the Darrin Fresh Water Institute and the Director of The Jefferson Project at Lake George.



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University of Michigan

Ph.D., Ecology and Evolution


Texas Tech University

M.S., Wildlife Management


State University of New York College of Environmental Science and Forestry

B.S., Environmental Forest Biology


Media Appearances

U.S. Megadrought Is Worst for Over 1,000 Years: How Long Could It Last?

Newsweek  print


...How Long Will the Megadrought Last? Like most droughts, it is difficult to predict how long the current event is going to last, according to Rick Relyea, director of the Darrin Fresh Water Institute at Rensselaer Polytechnic Institute...

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How IBM is using smart sensors and computer modeling at Lake George, NY

TechRepublic  online


IBM Research is working with partners from the Rensselaer Polytechnic Institute and The Fund for Lake George to place IoT-based sensors around Lake George, in New York, in order to monitor threats such as pollution from road salt, invasive species and excess nutrients.

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'The Jefferson Project' aims to solve water problem in Syracuse

Spectrum News  online


In 2013, the FUND for Lake George came together with IBM and RPI to create a sophisticated network of sensors designed to keep what Thomas Jefferson dubbed as the most beautiful water he ever saw, well, beautiful.

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Can Road Salt and Other Pollutants Disrupt Our Circadian Rhythms?

Scientific American  online


At Rensselaer Polytechnic Institute, my colleague Rick Relyea and his lab are working to quantify how increases in salinity affect ecosystems. Not surprisingly, they have found that high salinity has negative impacts on many species. They have also discovered that some species have the ability to cope with these increases in salinity.

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The Hidden Dangers of Road Salt

Smithsonian  online


“It has a really widespread number of effects on the whole food web or ecosystem,” says Rick Relyea, a professor of biological sciences at Rensselaer Polytechnic Institute. Relyea has studied how road salt runoff impacts lakes as part of the Jefferson Project at Lake George in New York state.

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The effect of a common pyrethroid insecticide on wetland communities

Environmental Research Communications

Jessica Hua, Rick Relyea


Within the past decade, the use of pyrethroid insecticides has drastically increased. While they are known to be directly toxic to aquatic organisms, based primarily on lab experiments, they are not expected to commonly contaminate aquatic ecosystems given their high binding affinities to organic material. However, increasing evidence suggest that pyrethroids do enter aquatic ecosystems via direct application, drift, and run-off. Despite the risks of these highly toxic chemicals, the full suite of direct and indirect effects of pyrethroid insecticides in wetland communities are not well understood. To address this gap, we examined the direct and indirect consequences of a common pyrethroid, permethrin, in complex aquatic mesocosms consisting of three trophic levels and 13 animal species. We found that permethrin was more lethal than laboratory toxicity assays suggest. Even the lowest concentrations of permethrin led to declines and extinctions in animals species across multiple trophic levels. The only animal species not negatively affected by permethrin were snails (Helisoma trivolvis and Physa acuta) and red-spotted newts (Notophthalmus viridescens). We also found that the direct effects of permethrin on anurans triggered indirect effects that facilitated periphyton abundance and increased the mass of those anurans that survived. As the use of pyrethroid insecticides continue to increase, understanding the direct and indirect effects of these insecticides on aquatic systems is critical to developing generalizations about their overall impact.

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Evolved tolerance to freshwater salinization in zooplankton: life-history trade-offs, cross-tolerance and reducing cascading effects

Philosophical Transactions of the Royal Society B

William D Hintz, Devin K Jones, Rick A Relyea


Recent discoveries have documented evolutionary responses to freshwater salinization. We investigated if evolutionary responses to salinization exhibit life-history trade-offs or if they can mitigate ecological impacts such as cascading effects through mechanisms of tolerance and cross-tolerance. We conducted an outdoor mesocosm experiment using populations of Daphnia pulex—a ubiquitous algal grazer—that were either naive or had previously experienced selection to become more tolerant to sodium chloride (NaCl). During the initial phase of population growth, we discovered that evolved tolerance comes at the cost of slower population growth in the absence of salt. We found evolved Daphnia populations maintained a tolerance to NaCl approximately 30 generations after the initial discovery. Evolved tolerance to NaCl also conferred cross-tolerance to a high concentration of CaCl2 (3559 µS cm−1) and a moderate concentration of MgCl2 (967 µS cm−1). A higher concentration of MgCl2 (2188 µS cm−1) overwhelmed the cross-tolerance and killed all Daphnia. Tolerance to NaCl did not mitigate NaCl-induced cascades leading to phytoplankton blooms, but cross-tolerance at moderate concentrations of MgCl2 and high concentrations of CaCl2 mitigated such cascading effects caused by these two salts. These discoveries highlight the important interplay between ecology and evolution in understanding the full impacts of freshwater salinization.

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Regulations are needed to protect freshwater ecosystems from salinization

Philosophical Transactions of the Royal Society B

Matthew S Schuler, Miguel Cañedo-Argüelles, William D Hintz, Brenda Dyack, Sebastian Birk, Rick A Relyea


Anthropogenic activities such as mining, agriculture and industrial wastes have increased the rate of salinization of freshwater ecosystems around the world. Despite the known and probable consequences of freshwater salinization, few consequential regulatory standards and management procedures exist. Current regulations are generally inadequate because they are regionally inconsistent, lack legal consequences and have few ion-specific standards. The lack of ion-specific standards is problematic, because each anthropogenic source of freshwater salinization is associated with a distinct set of ions that can present unique social and economic costs. Additionally, the environmental and toxicological consequences of freshwater salinization are often dependent on the occurrence, concentration and ratios of specific ions. Therefore, to protect fresh waters from continued salinization, discrete, ion-specific management and regulatory strategies should be considered for each source of freshwater salinization, using data from standardized, ion-specific monitoring practices. To develop comprehensive monitoring, regulatory, and management guidelines, we recommend the use of co-adaptive, multi-stakeholder approaches that balance environmental, social, and economic costs and benefits associated with freshwater salinization.

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