Nonnative and Invasive Species

The Rio Grande/Rio Bravo (hereafter referred to as the Rio Grande) in the Big Bend region of Texas, USA, and Chihuahua and Coahuila, Mexico, has substantially narrowed since the early 1900s. This narrowing has been caused by the construction and operation of dams and irrigation diversions in upstream reaches of the Rio Grande in the U.S. and the Rio Conchos in Mexico that has reduced flows without...

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...

Research using genetic principles, methods, and data provides critical information for restoration and conservation science. Genetic research may rely only upon genomic sequencing techniques, which generate abundant, genome-wide DNA sequences that can provide a glimpse into a species’ evolutionary history and adaptations. Genetic research may also look at an organism’s physical traits to...

In the western United States (U.S.), there are many regionally restricted, rare species resulting from complex demographic and ecological processes through time. In addition to the inherent risks associated with being rare (i.e., having few individuals spread over a limited area that could be disproportionately affected by chance events), anthropogenic disturbances are increasing in magnitude...

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...

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...

The desert Southwest is experiencing rapid development of utility-scale solar and wind energy facilities. Although clean renewable energy has environmental benefits, it can also have negative impacts on wildlife and their habitats. Understanding those impacts and effectively mitigating them is a major goal of industry and resource managers. One species of particular concern is Agassiz’s desert...

Southern Arizona’s semi-desert grasslands provides habitat for flora and fauna, regulates rainfall infiltration and overland flow, mitigates surface erosion and dust production, and sequesters carbon. Sustainable management is important to maintain these ecological services and is of concern for the managers, ranchers, and other people associated with the grassland.

Starting in 2017, U.S. Geological Survey (USGS) researchers and land managers are co-producing a network of restoration field trial sites on Department of Interior (DOI) and surrounding lands in the southwestern U.S. The network systematically tests restoration treatments across a broad range of environmental gradients. Each site in the network is used to test suitable seed mixes and treatments...

Although most introduced insects are relatively benign, some become high-impact pests causing widespread ecological and economic damage. Introduced insects that are specialists and feed on a single genus of plants can be high-impact as they can potentially eliminate an entire native plant genus over large areas. Luckily, most introduced insects with this feeding behavior do not become high-impact...

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...