The UK government is strategically releasing carefully bred species – including crayfish, weevils, and fungi – into the wild as a targeted biological control measure against destructive invasive plants and animals. This initiative, driven by ambitious environmental targets set by the Department for Environment, Food and Rural Affairs (Defra), aims to cut the establishment of non-native species by half by 2030.
The Strategy: Weaponizing Nature
The core idea is simple: introduce organisms that specifically target and weaken invasive species without harming native ecosystems. For example, South American weevils (Listronotus elongatus ) are being deployed against floating pennywort, a fast-spreading aquatic plant that suffocates rivers. Similarly, the psyllid Aphalara itadori is used to suppress Japanese knotweed, while the rust fungus Puccinia komarovii var. glanduliferae is trialed against Himalayan balsam.
The long-term goal is to let these biocontrol agents self-propagate, reducing the need for continuous human intervention. As Olaf Booy, deputy chief non-native species officer at the Animal and Plant Health Agency (Apha), explains, “Once the biocontrol agent is working properly, it should actually start to spread naturally… and bring that population of the non-native species down.”
Protecting Native Species Through Intervention
The program isn’t just about eliminating threats; it’s also about rescuing endangered native species. The invasive American signal crayfish has nearly wiped out Britain’s native white-clawed crayfish, outcompeting them and spreading a deadly plague. To counter this, scientists are creating protected “ark sites” and breeding programs to reintroduce the native crayfish into secure habitats. Hatcheries in Yorkshire and Devon are already releasing breeding-age crayfish into safeguarded rivers.
Emerging Threats: Raccoons and Disease
The government is also monitoring the rise of new invasive risks, particularly concerning escaped pets. Raccoons and raccoon dogs, increasingly popular due to social media trends, pose a potential threat as medium-sized predators that could decimate amphibian and bird populations. Currently, there is no mandatory registration for keeping these animals, raising concerns about accidental releases. Officials warn that escaped raccoons could also introduce new diseases into the ecosystem.
Economic Impact and Long-Term Goals
Invasive non-native species already cost the UK economy nearly £2 billion annually, damaging agriculture, infrastructure, and biodiversity. The current strategy is a proactive step toward mitigating these costs and protecting the country’s natural environment. By leveraging biological control and targeted conservation efforts, the UK aims to maintain its ecosystems’ resilience against future invasive threats.
The effectiveness of this program hinges on careful monitoring and adaptation, ensuring that the solutions deployed do not create unintended ecological consequences. Long-term success will depend on continued research, regulatory enforcement, and public awareness of the risks posed by invasive species.
