Scientist Spotlight: Bonnie Myers & the Shifting Assemblages of Freshwater Fish

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Learn about the work and research of Bonnie Myers, Research Fish Biologist for the National Climate Adaptation Science Center.

Ph.D. student, Bonnie Myers re-cementing pools in the Luquillo LTER artificial flumes to fix leaks.

Ph.D. student, Bonnie Myers re-cementing pools in the Luquillo LTER artificial flumes to fix leaks.

Credit: Ambar Torres Molinari

Extreme weather events like droughts and hurricanes are becoming increasingly more frequent and severe around the world. These events, which are predicted to become more common under a changing climate, can have dramatic impacts on local ecosystems. Bonnie Myers of the U.S. Geological Survey’s National Climate Adaptation Science Center (NCASC) has traveled far and wide across America to study the impacts of climate change and extreme weather events on one of the world’s most at-risk resources: inland fish.

“Talking to fishermen as an at-sea monitor about how their catches have been changing over the years really inspired me to study impacts of climate change on fish,” says Myers. “Developing more concrete paths for incorporating conservation and management of freshwater fish into climate adaptation plans could help improve the status of freshwater fisheries around the world.”

Myers’s career as a research fish biologist stems from an interdisciplinary background of climate science, science communication, and fish biology. Her work and research has taken her from Alaska to North Carolina, from Maine to Puerto Rico, and many places in between. She began her fish and wildlife conservation journey at the University of Wyoming, continued along this trajectory as a master’s student at Virginia Tech, and is now pursuing her Ph.D. at North Carolina State University. She has brought her diverse skillset to NCASC, where she works with a team of scientists synthesizing information on fish responses to environmental changes into a global database of impacts.

“Fisheries are very place-based,” says Myers. “Different factors can impact local fish populations, like land use change, temperature, stream flow, and presence of invasive species.”

As a master’s student, she gained considerable experience in inland fish research studying the relationships between temperature changes and fish production in cold-water Appalachian streams. Fish are highly vulnerable to fluctuations in water temperature and different fish species will adjust their regional distribution depending on these temperature changes. Fish will migrate, but only when an appropriate habitat exists and is accessible to them. Some species are able to expand their range as temperatures warm and become more suitable. Other fish species are less fortunate.

“Eastern Brook trout, for example, live in the Appalachian’s cold-water, higher-elevation streams,” says Myers. “They can’t exactly migrate outside of those streams, meaning many populations are at the top of their available habitat range already.”

This type of research is particularly important to the management of invasive and native fish species. Invasive fish have become an issue in part due to the management practice of stock-piling a variety of fish species in natural and artificial recreation areas across the country for recreational fishing. For instance, while brook trout are native to the Appalachian Mountains, rainbow trout are an invasive fish species in this region that have been introduced by humans into lakes and streams. The opposite relationship is true for Colorado, where brook trout is an invasive fish and rainbow trout is native.

“Brook trout in the Appalachian Mountains are a really important resource to the ecosystem and to the local communities, but their role is more complicated where the species is non-native,” says Myers.

Understanding how different species of fish react to various climate change impacts, like shifts in temperature, droughts, or flooding, and how the reactions of these species change regionally is vital to developing appropriate adaptation strategies for inland fisheries managers across the globe. Myers’s work at NCASC – collecting information on the impacts of climate change on inland fish into an accessible and user-friendly database – could benefit resource managers in a variety of regions that have conflicting management needs for their local fisheries.

“Are the fish species native to that ecosystem? If not, how does that impact other fish in the ecosystem?” says Myers. “That geographic context is so important and you can’t ignore how each species fits into their habitat.”

“Fisheries are very place-based. Different factors can impact local fish populations, like land use change, temperature, stream flow, and presence of invasive species.”

Currently, Myers is attempting to answer these questions as they pertain to the geography and climate of Puerto Rico, where it is projected that climate change will increase the magnitude of drought and flooding events. This project is part of Myers’s Ph.D. research at North Carolina State University under Dr. Tom Kwak. She describes the study as “a multi-level assessment to understand biotic resilience in native and non-native species and the mechanisms behind observed shifts in both populations as a result of these increasingly more frequent events.”

Myers is especially satisfied by the alignment of her project with NCASC’s objective for conducting place-based research on how changes in the environment might impact natural resources. One unique aspect of this project is that Myers will be able to expand what she learns in Puerto Rico to other Caribbean islands whose ecosystems are some of the most vulnerable to the negative effects of climate change.

“In terms of native species diversity, Puerto Rico can serve as a nice test case to help inform potential shifts for other islands,” says Myers. “Climate projections show there will be changes in the frequency and magnitude of drying and flooding events in the future for the Caribbean in general, so Puerto Rico is the perfect place to really understand the dynamics between changes in extreme events and native and non-native fish.”

Ph.D. student Bonnie Myers diving to assess a water pump for experiments in Puerto Rico.

Ph.D. student Bonnie Myers diving to assess a water pump for experiments in Puerto Rico.

Credit: Ambar Torres Molinari

Flood events are common in Puerto Rico, as well as occasional drought, but an increase in the intensity of both types of extreme events within a single ecosystem has many implications for regional wildlife, especially those that depend on water flow. For example, in the Caribbean, Dr. Kwak and colleague Dr. Alonso Ramírez suggest the region’s native fish species are typically more resilient to flash flooding, while invasive fish species tend to dominate after extended droughts. Myers wants to know what, specifically, is driving differences of fish resilience following different types of extreme weather events.

“Almost every river in Puerto Rico contains invasive species, from stocking practices or introductions, which impacts the native fish populations,” says Myers. “Research has shown that inland fish are some of the most vulnerable organisms to climate change, so my goal is to understand the impacts of climate change on fish in island ecosystems and how locals use the resource.”

This past summer, Myers completed two months of fieldwork with the help of Dr. Gus Engman and her technician Ámbar Torres conducting experiments with native and invasive fish species in artificial streams created to simulate drought and flood conditions being observed on the island. The next step for Myers will be to return to Puerto Rico next year and conduct additional experiments to compare different groups of fish species. The data collected from her project will ultimately be combined with existing data on fish responses to climate change to create projections of how fish diversity will look in Puerto Rico in the future. Finally, Myers will relate what she has learned back to the local community.

“A lot of recreational activities occur in Puerto Rico’s rivers and streams so we’re trying to get a better understanding of how local communities view and use freshwater fish,” she says.  

During her upcoming trips, Myers plans to conduct focus groups which will help her create a survey she will distribute among the general public. Survey responses will be used to develop a better understanding of the value and uses of the native and non-native freshwater fish in Puerto Rico. Myers’s surveys will provide Puerto Rican resource managers with information on how the island’s rivers, streams, and lakes are being used. She is working closely with the U.S. Fish & Wildlife Service and the Puerto Rico Department of Natural and Environmental Resources to ensure the data she collects on freshwater fish dynamics during extreme weather events is applicable to managers and local communities alike.

“A better understanding of the uses and value of Puerto Rico’s inland fisheries could provide valuable information to decision-makers and managers,” says Myers, whose project will end with a heavy focus on how Puerto Rican communities view their native and invasive fish populations.

“An important lesson I’ve learned along the way is to always connect the impacts on the resource to the various stakeholders involved,” says Myers. “It’s particularly important to the communities using that resource of freshwater fish.”


Bonnie Myers has worked as a fisheries and wildlife technician in Colorado and Wyoming, taught 8th grade science in Memphis, Tennessee as a Teach for America corps member, and worked in Gloucester, Massachusetts as a fisheries observer. She received her B.S. in Wildlife and Fisheries Biology and Management from the University of Wyoming, and completed her M.S. in Fish and Wildlife Conservation from Virginia Tech in 2014. After graduate school, she was a 2014 Knauss Fellow in NOAA Research's Office of Communications, a role which led to her current position as a research fish biologist at the National Climate Adaptation Science Center. Myers was also a 2018-2019 Global Change Fellow for the Southeast Climate Adaptation Science Center and was recently featured in a brief interview about her accomplishments. Finally, her work in Puerto Rico is part of her Ph.D. research as a graduate student in the Fish, Wildlife and Conservation Biology Program of North Carolina State University’s Department of Applied Ecology working with Dr. Tom Kwak with the USGS North Carolina Cooperative Fish and Wildlife Research Unit. Check out photos from her adventures below, along with a video of the artificial streams she used in her experiments!