Aquatic Ecosystems

Sandbars have been used as campsites by river runners and hikers since the first expeditions to the region more than 100 years ago. Sandbar campsites continue to be an important part of the recreational experience for the more than 25,000 hikers and river runners that visit the Colorado River corridor each year. Because the Colorado River is dominated by bedrock cliffs and steep talus slopes...

The Grand Canyon Monitoring and Research Center develops and collaborates with other science centers to create online data applications that provide access to project data as it becomes available to the public. Some of these applications provide data in near real-time, while other project data are updated at some regular interval (annually, quarterly). Content listed here include applications that...

The Grand Canyon Monitoring and Research Center offers a collection of data resources and online tools -- including web maps, applications, and other content -- that convey scientific information related to on-going monitoring of the Colorado River. Some applications are a culmination of long-term monitoring work, while others are developed around more a specific set of information usually derived...

The Upper Mississippi River (UMR) provides critical habitat for hundreds of aquatic species and provides Minnesota with a transportation link to the rest of the world. Reliable measurements of sediment are important for making decisions as part of maintaining the channel. In 2014, sediment deposition in the navigation channel caused channel closures of the UMR delaying commercial navigation for 3...

The goal of Grand Canyon Monitoring and Research Center’s (part of the Southwest Biological Science Center) riparian vegetation monitoring program is to assess changes and trends in plant species composition and cover and relate those changes to Glen Canyon Dam operations, river hydrology, climate, and geomorphology. Monitoring is done by annual field-data collection on plant cover and diversity...

Riparian areas are conspicuous belts of dense, green vegetation along streams and rivers, and can be considered “ribbons of life”. Despite covering less than 2 percent of the land area in the southwestern U.S., riparian areas tend to have high species diversity and population density, making them valuable to managers, scientists, and the public. These unique ecosystems act as a link between dry...

Just below Glen Canyon Dam on the Colorado River is a very popular Blue Ribbon trout fishery known for its rainbow trout. However, approximately 78 miles downstream, near were the Little Colorado River flows into the Colorado River, is a population of endangered humpback chub. The introduced rainbow trout can negatively affect native humpback chub by competing with them for food (immature black...

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...

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...

Introductions of bio-control beetles (genus Diorhabda) are causing defoliation and dieback of exotic Tamarix spp. in riparian zones across the western U.S., yet the factors that determine the plant communities that follow Tamarix decline are poorly understood. In particular, Tamarix-dominated soils are often higher in nutrients, organic matter, and salts than nearby soils, and these soil...

Rainbow trout is a desirable sport fish that has been introduced in many locations around the world. Although introductions of rainbow trout and other nonnative fishes provide recreational fishing opportunities, they also pose threats to native fish populations. The Glen Canyon Dam Adaptive Management Program has tasked scientists and managers with identifying management options that allow rainbow...