# Invasive Species Tools

## Science Center Objects

Tracking the establishment and spread of existing and new invasive species is critical to effectively manage invasive species. In addition to standard means of monitoring, the USGS is developing new tools, particularly molecular techniques, to assist in the early detection of invasive species.

eDNA

Environmental DNA (eDNA), a genetic material shed by organisms into the waters in which they live, has recently emerged as a powerful genetic tool for detecting invasive species and rare aquatic animals.  This technology involves detection of DNA in an environmental sample, such as lake or river water.

USGS research has led to refinements to past methods to improve detection sensitivity, understand how eDNA changes over time once it’s shed from live fish, and decrease time between sampling and results. Specific USGS research includes developing genetic markers and sampling protocols for species such as Asian carp, Burmese python (Python bivittatus), Argentine Black and White Tegu (Salvator merianae), sunfishes, crayfishes, New Zealand Mudsnail (Potamopyrgus antipodarum), Eurasian watermilfoil (Myriophyllum spicatum) and Northern Pike (Esox lucius).

Genetic Tools for Zebra and Quagga Mussels

Invasive zebra and quagga mussels (collectively called dreissenid mussels) are causing significant ecological and economic impacts and the range of these impacts continues to increase as they spread across North America. USGS conducts dreissenid mussel rapid response research in the Great Lakes and Upper Mississippi River basins including development of genetic tools for dreissenid mussel detection. For example, scientists are evaluating the use of eDNA to help direct dreissenid mussel control efforts on inland lakes, and determining if eDNA can be used to for monitoring even under winter conditions. Scientists are also testing a portable rapid eDNA detection kit for dreissenid mussel detection.

In 2016 the first detection of dreissenid mussel larvae was documented in Montana. This detection triggered the launch of the DOI Invasive Mussel Initiative DOI Invasive Mussel Initiative to identify opportunities for the federal government to strengthen efforts, in coordination with states and tribes, to address invasive mussels in the Columbia River Basin and across the West. In support of this effort, the USGS evaluated genetic markers for dreissenid mussel early detection and is working to improve environmental DNA sampling and analysis protocols. USGS work also included the development of a variety of risk-based, early detection monitoring plans in the Northern Rocky Mountains.

"Lab in a Suitcase" set up in the field to test samples for the fungus (Ceratocystis fimbriata) responsible for Rapid ‘Ōhi‘a Death.

(Credit: Carter Atkinson, USGS. Public domain.)

Lab in a Suitcase

Rapid Ōhia Death is a fungal disease of the ōhia lehua tree that is native to the Hawaiian Islands. USGS scientists worked with collaborators at the USDA Agricultural Research Service to develop, test and validate a field method to detect the fungus that causes Rapid Ohi’a Death in mature trees. This portable "Lab in a Suitcase" allows for rapid detection of the fungus and is being used by the Big Island Invasive Species Committee to detect infected trees. A full report on the methods and field application is available.

USGS has been involved in the response to Rapid Ohi’a Death since its detection in 2015, and is part of the multi-organizational Rapid Ohi’a Death Working Group which was formed to share information and coordinate research, resource management and outreach activities.

Current USGS Research: Pathways for Movement and Rate of Spread of Rapid ‘Ōhi‘a Death on the Island of Hawai‘i