Cruising for clues: discovering invasive species in the Arctic with eDNA

The groundbreaking study, published this week (8 September 2025) in Global Change Biology by researchers at British Antarctic Survey (BAS), provides the first evidence of a non-native invasive barnacle species in Arctic Canada.

Climate change is warming the Arctic nearly four times faster than anywhere else on Earth. As a result, Canada’s Arctic waters are losing their thermal barrier against invasive species. Previously, these cold waters prevented invasive species travelling north and establishing populations. 

The scientists used eDNA metabarcoding – a technique that can identify multiple species from a single water sample – to make the discovery. As organisms move through water, they leave behind genetic traces through skin cells, waste and other biological materials - known as environmental DNA (eDNA). The researchers collected these eDNA samples whilst on cruise ships operating on busy Arctic shipping routes. Using this technique, scientists can now detect invasive species without ever seeing them. 

The researchers detected a bay barnacle (Amphibalanus improvisus), an invasive marine species that is already prevalent in European waters and the Pacific Ocean, contributing to biofouling of ships, pipelines and other infrastructure, and ecological disruption. 

The detection of this barnacle marks the first identification of this animal in the Canadian Arctic marine environment, proving that eDNA metabarcoding is an effective tool for monitoring the arrival of invasive species. 

Marine invasive species typically arrive in Arctic Canada on ship hulls and in their ballast water. This shipping traffic has increased by over 250% since 1990 with scientists now investigating the increased ecological risks this presents. 

Lead author Elizabeth Boyse, an ecologist at British Antarctic Survey, explained:

 “Climate change is really at the core of this problem. Ships are increasing in number because of reduced sea ice opening new shipping routes. Add to this, the invasive species that the ships bring to the Arctic, are also more likely to survive and establish populations because of warmer water temperatures.”

Invasive species present various challenges. They can outcompete native organisms, disrupting ecosystems and affecting indigenous communities who rely on marine resources for food security. Between 1970-2017, aquatic invasive species have cost around $345 billion through damage to infrastructure, disruption of local ecosystems and management efforts.

Scientists will now determine whether the detected barnacle represents passing larvae or a breeding population. The authors say that using eDNA to detect non-native species in understudied areas, in combination with direct observations by citizen scientists and local communities, could provide a key monitoring tool for detecting invasive species in this rapidly changing area. 

Expanding monitoring capacity for potential invasive species in Arctic Canada with environmental DNA metabarcoding by Boyse, E., et al is published in Global Change Biology. 

ENDS.