Aquatic Ecosystems

Partners in Science is a collaborative effort between Grand Canyon Monitoring and Research Center, Grand Canyon Youth, and the National Park Service to provide opportunities for youth to engage in scientific field research in Grand Canyon. This partnership connects youth from diverse backgrounds with the Nation’s natural and cultural resources on 2-3 river-based expeditions on the Colorado River...

The Southwest Biological Science Center (SBSC) conducts and provides scientific information as part of our mission and Federal Trust Responsibility to strengthen relationships and build partnerships with sovereign tribal nations. Here, we highlight a few examples of projects with tribal partners.

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...

USGS Southwest Biological Science Center's Grand Canyon Monitoring and Research Center provided scientific expertise to evaluate potential effects of reservoir management on various resources in Lake Powell and Grand Canyon. This information, published in a cooperator report, was requested and used by the Bureau of Reclamation for decision-making on water flows from Glen Canyon Dam.

Grand Canyon National Park is a hotspot for bat diversity. Twenty-two bat species have been documented in the Park, more than any other national park unit.

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...

Glen Canyon Dam has altered flow and sediment dynamics of the Colorado River in Grand Canyon. Before the dam was completed in 1963, the Colorado River carried a large amount of sand, silt, and clay through Grand Canyon, some of which was deposited during spring floods to create large and abundant sandbars. Sandbars in Grand Canyon are valued as camping areas, create aquatic and riparian habitat...

The Grand Canyon Monitoring and Research Center currently functions under a Triennial Work Plan (TWP) which is thoroughly reviewed and vetted both internally within the Center and through the GCDAMP Technical Work Group (TWG) and the Adaptive Management Work Group (AMWG). These advisory panels have been a part of the Glen Canyon Dam adaptive management process since the inception of the GCDAMP...

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...

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...

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...

We study the links among different geomorphic processes that affect river valley landscapes in the Colorado River downstream from Glen Canyon Dam, Arizona. Dam-released flows affect the deposition and retention of sandbars that serve as sources for other sand resources, such as windblown sand dunes, throughout the Colorado River ecosystem.