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Rick Relyea - Rensselaer Polytechnic Institute. Troy, NY, US

Rick Relyea

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


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

Areas of Expertise (8)

Aquatic Ecosystems‎

Global Change

Climate Change




Animal Behavior

Animal Disease Ecology


Rick Relyea earned his Ph.D. at the University of Michigan in 1999, and then spent the next 15 years as a professor at the University of Pittsburgh. There, he also served as the director of the university's 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 of The Jefferson Project at Lake George. In addition to teaching and conducting leading-edge research, Relyea has authored several textbooks in the fields of biology, ecology, and environmental science.



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Jefferson Project Year Five Rick Relyea, Ph.D. - Virtual Reunion & Homecoming - Fall 2021 Conference by Rick Relyea Jefferson Project Interview 2017


Education (3)

University of Michigan: Ph.D., Ecology and Evolution 1998

Texas Tech University: M.S., Wildlife Management 1992

State University of New York College of Environmental Science and Forestry: B.S., Environmental Forest Biology 1989

Media Appearances (9)

If America's Megadrought Continues, the Impact Will Be Catastrophic

Newsweek  online


"This region is experiencing an exceptional drought condition, with a severity that we have not seen in the past 1,200 years," Rick Relyea, director of the Darrin Fresh Water Institute at Rensselaer Polytechnic Institute, told Newsweek.

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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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Road salt triggering 'massive' harm to US lakes, contaminating drinking water, studies warn

USA Today  online


[No Abstract Available]

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Why Road Salt is Bad for the Environment

Discover Magazine  online


“We walk on it, we drive on it — it’s pervasive,” says Rick Relyea, an ecologist with Rensselaer Polytechnic Institute, a private university in New York. “It’s really one of the most pervasive contaminants in northern latitudes that we, relatively speaking, know very little about.”

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Road Salt Works. But It’s Also Bad for the Environment.

The New York Times  online


[No Abstract Available]

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Citing danger to freshwater, scientists say we need to put brakes on road salts

The Washington Post  online


Every winter, de-icing salts — sodium chloride, calcium chloride and magnesium chloride — battle icy roads nationwide. The effort is epic in scope: Hundreds of millions of gallons of salty substances are sprayed on roads and billions of pounds of rock salt are spread on their surfaces each year. That may lead to safer roads, but it has a real effect on the planet. In a review in the journal Frontiers in Ecology and the Environment, a group of environmental scientists looked at the hazards of salts that make driving safer.

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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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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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Articles (4)

Direct and indirect effects of climate change on distribution and community composition of macrophytes in lentic systems

Biological Reviews

Lovisa Lind, R Lutz Eckstein, Rick A Relyea

2022 Macrophytes are an important part of freshwater ecosystems and they have direct and indirect roles in keeping the water clear and providing structure and habitats for other aquatic organisms. Currently, climate change is posing a major threat to macrophyte communities by altering the many drivers that determine macrophyte abundance and composition. We synthesise current literature to examine the direct effects of climate change (i.e. changes in CO2, temperature, and precipitation patterns) on aquatic macrophytes in lakes as well as indirect effects via invasive species and nutrient dynamics. The combined effects of climate change are likely to lead to an increased abundance and distribution of emergent and floating species, and a decreased abundance and distribution of submerged macrophytes. In small shallow lakes, these processes are likely to be faster than in deep temperate lakes; with lower light levels, water level fluctuations and increases in temperature, the systems will become dominated by algae. In general, specialized macrophyte species in high-latitude and high-altitude areas will decrease in number while more competitive invasive species are likely to outcompete native species. Given that the majority of endemic species reside in tropical lakes, climate change, together with other anthropogenic pressures, might cause the extinction of a large number of endemic species. Lakes at higher altitudes in tropical areas could therefore potentially be a hotspot for future conservation efforts for protecting endemic macrophyte species. In response to a combination of climate-change induced threats, the macrophyte community might collapse, which will change the status of lakes and may initiate a negative feedback loop that will affect entire lake ecosystems.

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The effect of a common pyrethroid insecticide on wetland communities

Environmental Research Communications

Jessica Hua, Rick Relyea

2019 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

2018 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

2018 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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