Hydropower

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...

There are more than 92,000 dams in the United States, of which at least 3% of these produce hydropower. Hydropower projects create renewable energy but also can alter habitats, restrict upstream and downstream movements of fishes and other aquatic organisms, and may stress, injure or kill migrant fishes and other aquatic organisms. In addition, there are more than 5 million culverts and other road...

The federally-listed threatened humpback chub is a native fish of the Colorado River. Despite the environmental changes to the river following the construction of Glen Canyon Dam, humpback chub persists alongside nonnative species, including rainbow trout. The pre-dam Colorado River experienced seasonal variation in temperature and discharge. Seasonal flooding resulted in sediments carried...

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...

Glen Canyon Dam has altered ecological processes of the Colorado River in Grand Canyon. Before the dam was built, the Colorado River experienced seasonable variable flow rates, including springtime flooding events. These spring floods scoured the river bottom and enhanced natural processes that sustained the Colorado River ecosystem. Since the dam’s construction in 1963, springtime floods have...

Dams can be found in just about every major river, and for good reason. Society has received many benefits like flood control, hydropower, water supply storage, and places to recreate. However, many fish and other life in our rivers can’t swim around these barriers. Often, the best spot for a fish to live and reproduce is out of reach because they can’t pass by a dam. This has not gone unnoticed...

Recent discoveries of the extent of sturgeon movement in the Gulf of Maine combined with relicensing and water use issues in the Connecticut River demand closer evaluation of shortnose and Atlantic sturgeon migration and behavior patterns.

The overall goal of this project is to advance inter- and trans-disciplinary research coordination, focusing on the transformation of social-ecological systems by hydroelectric dam construction in the Amazon and the United States. The experience gained by Southwest Biological Science Center researchers working on the Glen Canyon Dam Adaptive Management Program in the Colorado River in Grand Canyon...

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...

Scientists in the Aquatic Systems Branch have been studying the impacts of dams on riverscapes for more than two decades. Our scientists have written many reports on the effects of dams on recruitment of bottomland pioneer trees, such as cottonwood, along the Upper Missouri River and the Bill Williams River, and the effects of dams on channel geometry and vegetation throughout the Great Plains...