Kathrine (Kate) Behn
Kathrine (Kate) Behn is a fish biologist with the USGS Southwest Biological Science Center’s Grand Canyon Monitoring and Research Center in Flagstaff, AZ.
Kate’s work at the USGS Southwest Biological Science Center focuses on the feeding ecology of both native and invasive fishes in the Colorado River through Glen and Grand Canyons in support of resource management decisions. In addition, she coordinates interagency fish data archiving to support long‑term monitoring efforts. She also participates in Lake Powell field campaigns that track water quality and ecological conditions in the reservoir. Through these projects, her work contributes to understanding ecosystem processes as the system adjusts to drought, low water levels, and higher temperatures.
Science and Products
Early detection of aquatic threats: eDNA research in the Colorado River ecosystem & Lake Powell
The USGS and partners are conducting environmental DNA (eDNA) research in the Colorado River downstream from Glen Canyon Dam and in Lake Powell to detect invasive fish species and other aquatic threats before they become established. eDNA is a cutting-edge technology that makes it possible to identify invasive species before they are visible, even in vast or hard-to-survey environments like rivers...
Lake Powell Research
Lake Powell is a large arid reservoir that represents about 70% of the water storage capacity for the Upper Colorado River Basin. It is the second largest reservoir in the United States by capacity (second only to Lake Mead). Lake Powell is an oligotrophic reservoir, which means that nutrient concentrations and algal production are generally low. This often results in very clear-water conditions...
Humpback Chub in the Colorado River, Grand Canyon
Threatened humpback chub are a native fish found only in the Colorado River Basin. Once found in warm-water canyons in the Basin, the largest population now persists in the Colorado River in Grand Canyon National Park, downstream of Glen Canyon Dam and Lake Powell reservoir.
Rainbow Trout in the Colorado River, Grand Canyon
Rainbow trout are a desirable sport fish that have been introduced in many locations around the world, including the Colorado River. Although introductions of rainbow trout and other nonnative fishes provide recreational fishing opportunities, they can also pose threats to native fish populations. The Glen Canyon Dam Adaptive Management Program has tasked scientists and managers with identifying...
Community Science in Grand Canyon
Aquatic insects are important components of riverine foodwebs as they are prey for fish, birds, bats, lizards, and spiders. The closure of Glen Canyon Dam in 1963 fundamentally altered the hydrology, water temperature, and turbidity of the Colorado River through Grand Canyon. These changes, along with competition with invasive species and limited food availability have led to the decline and...
Bug Flows: Improving Food Web Health on the Colorado River
Native and desired nonnative fish downstream of Glen Canyon Dam are food limited—meaning that if more or larger invertebrate food items were available, there would be more and larger fish. Aquatic insects have complex life cycles that include egg, larvae, and pupal stages that are aquatic while adults have wings and are typically terrestrial. Aquatic insects are a fundamental component of river...
Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
Invertebrate Drift Downstream of Colorado River Basin Dams
Aquatic invertebrates are critical food for fish and other species that inhabit large rivers. In the Colorado River Basin, invertebrates that get transported down the river (“in the drift”) are particularly important to rainbow trout and other species of interest to recreational users. This research seeks to compare rivers downstream of large dams throughout the Colorado River Basin in order to...
Aquatic Insects
Aquatic insects live in the water as larvae most of their lives, then emerge onto land for a brief period as winged adults. Sampling these emerged adults on land is therefore a useful tool for understanding the condition of the aquatic insect population that is in the water, particularly in large rivers where sampling the larvae on the river bed is impractical. Our group uses a variety of methods...
Science and Products
Early detection of aquatic threats: eDNA research in the Colorado River ecosystem & Lake Powell
The USGS and partners are conducting environmental DNA (eDNA) research in the Colorado River downstream from Glen Canyon Dam and in Lake Powell to detect invasive fish species and other aquatic threats before they become established. eDNA is a cutting-edge technology that makes it possible to identify invasive species before they are visible, even in vast or hard-to-survey environments like rivers...
Lake Powell Research
Lake Powell is a large arid reservoir that represents about 70% of the water storage capacity for the Upper Colorado River Basin. It is the second largest reservoir in the United States by capacity (second only to Lake Mead). Lake Powell is an oligotrophic reservoir, which means that nutrient concentrations and algal production are generally low. This often results in very clear-water conditions...
Humpback Chub in the Colorado River, Grand Canyon
Threatened humpback chub are a native fish found only in the Colorado River Basin. Once found in warm-water canyons in the Basin, the largest population now persists in the Colorado River in Grand Canyon National Park, downstream of Glen Canyon Dam and Lake Powell reservoir.
Rainbow Trout in the Colorado River, Grand Canyon
Rainbow trout are a desirable sport fish that have been introduced in many locations around the world, including the Colorado River. Although introductions of rainbow trout and other nonnative fishes provide recreational fishing opportunities, they can also pose threats to native fish populations. The Glen Canyon Dam Adaptive Management Program has tasked scientists and managers with identifying...
Community Science in Grand Canyon
Aquatic insects are important components of riverine foodwebs as they are prey for fish, birds, bats, lizards, and spiders. The closure of Glen Canyon Dam in 1963 fundamentally altered the hydrology, water temperature, and turbidity of the Colorado River through Grand Canyon. These changes, along with competition with invasive species and limited food availability have led to the decline and...
Bug Flows: Improving Food Web Health on the Colorado River
Native and desired nonnative fish downstream of Glen Canyon Dam are food limited—meaning that if more or larger invertebrate food items were available, there would be more and larger fish. Aquatic insects have complex life cycles that include egg, larvae, and pupal stages that are aquatic while adults have wings and are typically terrestrial. Aquatic insects are a fundamental component of river...
Uncovering the Base of the Food Web: Primary Production Dynamics in the Colorado River
Algae, phytoplankton, and rooted macrophytes represent the base of many aquatic food webs and are known as primary producers. Through photosynthesis, these organisms convert sunlight energy into chemical energy (i.e., carbon) that in turn fuels the growth of animals such as macroinvertebrates and fish. This project uses high frequency measurements of dissolved oxygen, which is a by-product of...
Invertebrate Drift Downstream of Colorado River Basin Dams
Aquatic invertebrates are critical food for fish and other species that inhabit large rivers. In the Colorado River Basin, invertebrates that get transported down the river (“in the drift”) are particularly important to rainbow trout and other species of interest to recreational users. This research seeks to compare rivers downstream of large dams throughout the Colorado River Basin in order to...
Aquatic Insects
Aquatic insects live in the water as larvae most of their lives, then emerge onto land for a brief period as winged adults. Sampling these emerged adults on land is therefore a useful tool for understanding the condition of the aquatic insect population that is in the water, particularly in large rivers where sampling the larvae on the river bed is impractical. Our group uses a variety of methods...