USGS and AFS Host Capitol Hill Roundtable on Extreme Events

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Inland fish are found in lakes, rivers, streams, canals, reservoirs, and other landlocked waters. Although these landlocked waters make up only 0.01% of total water on the planet, they provide over 40% of finfish production. Due to their close proximity with people, inland fish are vulnerable to a range of threats, including overharvesting, invasive species, pollution, and global change.

Scientists with the USGS National Climate Adaptation Science Center (NCASC) are investigating how climate-related changes, such as droughts and warming waters, impact inland fish. For example, Research Fish Biologists Abigail Lynch and Bonnie Myers recently published a synthesis of global trends in inland fish response to climate change. This research will help resource managers anticipate future changes to fish populations, enabling them to develop more strategic and effective management plans.

On April 12, the USGS, together with the American Fisheries Society (AFS), hosted a roundtable discussion with congressional staff centered on the impacts of extreme weather events like hurricanes, floods, droughts, and wildfires on inland fish. USGS scientists and AFS Executive Director, Doug Austen, explained that as these extreme events increase in frequency and severity, they will have significant ecological consequences for inland fisheries and social implications for communities that rely on recreational fishing as an important economic driver.

As part of the roundtable, Doug Beard, acting director for the USGS Land Resources Mission Area (formerly Climate and Land Use), discussed how the important fisheries research NCASC and other USGS scientists are doing across the country equips natural resource professionals with information and tools to more effectively manage fisheries in the face of changing ecosystems.

For example, USGS scientists are evaluating and developing methods for controlling aquatic invasive species through chemical, biological, and physical means in the Great Lakes. Bo Bunnell, a USGS research fisheries biologist with the Great Lakes Science Center, provided a concrete example of the types of fisheries impacts that could result from an extreme event: flooding in the Midwest. He explained how extreme flooding in the Illinois River watershed could make Lake Michigan more vulnerable to the invasion of Asian carp, where they could devastate native fish populations and a $1 billion fishing industry. However, Bo also noted that recent investments made by the Great Lakes Restoration Initiative, a federal program aimed at restoring the health of the Great Lakes, are helping combat the spread of invasive carp. Clint Muhlfeld, acting manager of the USGS Fisheries Program, also explained how the Fisheries Program is working on cutting edge research that leads to the protection and restoration of United States fisheries, the habitats that support them, and the services they provide.

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Another extreme event that impacts inland fish is wildfires. Wildfires can create sediment, debris, and ash that enter waterways, as well as increase water temperature for a prolonged period of time. These disturbances dam streams, alter water quality, and ultimately stress fish, potentially leading to population declines. For example, during the 2016 fire season, nearly 70,000 wildfires burned 5.5 million acres across the country. Bull trout in Washington’s Wenatchee River basin are already isolated, and their habitat was further fragmented by debris flows and landslides following wildfires. While uncontrolled fires can cause serious impacts on fish, prescribed burns can actually help prevent “megafires”, reducing destructive debris and enhancing connections between rivers.