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In 2021 a team of scientists from the University of Iowa, US, deployed innovative eDNA detection techniques to identify water courses where the New Zealand mud snail may be hiding unseen, which should allow them to identify the scale of the problem and deploy early interventions to keep populations in check before they do visible, irreversible damage.

Invasive species are notoriously challenging to track due to their ability to rapidly spread from one habitat to another, whilst their impacts on endangered species can be even more difficult to detect. Two new studies published in the journal Current Biology have now shown that it is possible to accurately identify a variety of animal species over distances of hundreds of metres by sampling environmental DNA (eDNA), or DNA traces shed by animals into the surrounding air.

The Pennsylvania Fish and Boat Commission (PFBC) announced that it has conducted targeted invasive carp sampling in Presque Isle Bay, Erie County, after the U.S. Fish and Wildlife Service (USFWS) detected the presence of Silver Carp environmental DNA (eDNA). While no physical invasive carp specimens have been detected, the PFBC has requested that the USFWS collect additional water samples from Presque Isle Bay in the fall when more favorable environmental conditions are present for eDNA sampling. Members of the public can report sightings of aquatic invasive species to the PFBC using its online form.

Environmental DNA (eDNA) has gone from new science on the block to a star of the show. With just a water, soil, or snow sample, ecologist Tommy Franklin and fellow scientists at the Rocky Mountain Research Station are detecting rare aquatic and terrestrial species by identifying the genetic material they leave behind.

Scientists at the Rocky Mountain Research station recently used eDNA to preserve headwater bull trout populations in a warming climate, track white nose syndrome — a killer bat fungus, and reveal the role of human transport in the spread of invasive northern pike in the Columbia River basin. A recent article highlights eDNA research at the station and features National Genomics Center Director Mike Schwartz.

Environmental DNA is developing into a powerful tool for improving the monitoring and detection of invasive species, which may be present in low numbers and therefore difficult to find. There are a wide range of ongoing efforts by federal and non-federal groups working to improve and apply eDNA to invasive species monitoring and management.

The NISC FY2020 to FY2022 Work Plans incorporated interagency work on eDNA, including the following outputs:

• The NISC white paper has been released (May 2022): Environmental DNA as a Tool for Invasive Species Detection and Management [PDF, 295 KB]

Assays of environmental DNA — traces of genetic material found in air, soil, and water — may improve scientists’ ability to detect bat roosts and track the spread of white-nose syndrome, a disease caused by a killer fungus spread easily in the close quarters of hibernacula. In this research, scientists experienced success in detecting bats in field collected samples of environmental DNA, though the technology is still in the experimental stage.

Invasive zebra and quagga mussels are an immediate threat to Western states. With no controls, they spread rapidly, foul boats and equipment, clog water intake, and increase costs to hydropower operations and municipal water utilities. Even dead mussels can be a nuisance, littering beaches with shells. Management of these invaders is expensive; in the Great Lakes, managing mussels costs about $500 million annually. Until 2007, the mussels were limited to waterways and lakes east of the Mississippi, but now they have spread westward. In 2016, quagga mussels were found in Lake Powell.

Unfortunately, there are no foolproof existing technologies or treatments to eradicate established mussel populations in large, open water systems in an environmentally sound manner. Early warning, however, helps us prepare before the mussels or other invasive species arrive.

Northern pike are native to Alaska, Canada, and much of the central and eastern continental United States. Genetic evidence reveals the role of human transport in the spread of invasive northern pike in the Columbia River basin.

Natural resource managers in British Columbia discovered several adult male and female European green crabs on Haida Gwaii this past July. Alarm bells immediately went off for biologists in Alaska. The archipelago of Haida Gwaii, off the coast of Prince Rupert in British Columbia, is very close to Alaska. The July discovery is the closest confirmed finding of the invasive crustacean since it was first detected in the San Francisco Bay area in 1989.