READI-Net: Using Environmental DNA to Catch Invasive Species Early

The sooner an invasive species is found, the more likely it can be controlled — and the cheaper that control will be. One of the most sensitive ways to find new invaders is environmental DNA (eDNA) sampling. The U.S. Geological Survey's Rapid eDNA Assessment and Deployment Initiative & Network (READI-Net), designed with partners, aims to give managers a complete toolkit for using eDNA to detect aquatic invasive species.

READI-Net supports the Department of the Interior's National Early Detection and Rapid Response Framework, a coordinated strategy to find and eradicate invasive species in new habitats before they become established, spread and cause harm.

Environmental DNA offers early detection for invasive species management, and READI-Net provides the tools to use it (USGS).

Why early detection matters

Invasive species, pathogens and parasites can harm the environment, the economy and human health, destroying crops, damaging infrastructure, spreading disease to wildlife and people, and even driving native plants and animals to extinction. Aquatic invaders can reshape food webs and communities, disrupt recreation, and severely affect fisheries and hydroelectric infrastructure. Over the past 50 years, aquatic invasive species alone have caused at least $423 billion in damage and management costs worldwide.

Invasive mussels encrusting a propeller, making it inoperable (National Park Service photo).

How eDNA works

Organisms such as fish and mussels shed genetic traces into the water. eDNA methods capture and identify those traces without ever seeing the animals, and even tiny amounts can be detected. A water sample can reveal a target species with high confidence even when it's too scarce to find with visual methods such as trawl nets.

Six components

READI-Net's tools can be used individually or as a full set, to suit different needs and budgets:

1. Autonomous eDNA samplers — cut the cost of surveillance, raise the odds of sampling at the right place and time to catch a new invasion, track changes in communities over time, and store as many as 144 samples per deployment, improving the chances of detecting hard-to-find new invaders or rare native species.
2. Broad-spectrum surveillance — cost-effective molecular tests that detect DNA from many species at once, across groups such as algae, mussels and fish, from a single sample.
3. Where and when to sample — statistically informed guidance on designing studies with autosamplers.
4. Lab analysis standards — standardized, repeatable techniques; a quality management system to catch and fix problems; verifiable, transparent results; and barcode tracking of samples across labs.
5. Information framework — delivers eDNA results to managers, policymakers, municipalities, scientists and the public through user-friendly dashboards, respects jurisdictional authority, states uncertainty and limitations clearly, supports big-data use and follows federal data release practices.
6. Communication — builds networks of eDNA users and links with existing networks, such as USGS water monitoring, for more analytical power.

The six components of READI-Net (USGS).

Who can use it

Federal and state agencies, Tribes, municipalities, scientists and resource managers who want to start or continue eDNA surveillance of aquatic threats — for early detection or for checking results after treatment — can draw on READI-Net's end-to-end support, which was built from research with federal, state and Tribal input.

An autonomous eDNA sampler that captures, filters and preserves samples at user-set intervals, such as every 3 hours (USGS photo).

Sources

• U.S. Geological Survey: "READI-Net—Providing tools for the early detection and management of aquatic invasive species," USGS Fact Sheet, citing Roy and others (2023) and Smith and others (2015); a work of the United States government in the public domain.