Invasive Species Strategy 2026–2030
Our Vision
To protect and restore the rivers, lakes, wetlands and riparian habitats of the Sligo Bay Catchment by preventing the spread of invasive non-native species and reducing their impact on biodiversity, water quality, ecosystem function and community enjoyment of our natural environment.
Introduction
Invasive non-native species (INNS) are one of the greatest threats to biodiversity within the Sligo Bay Catchment. They can outcompete native plants, alter habitats, accelerate riverbank erosion, reduce ecological resilience and negatively impact recreation, fisheries and water quality.
The Sligo Bay Catchment Rivers Trust is committed to working collaboratively with landowners, local communities, public bodies and volunteers to control and manage invasive species using evidence-based and environmentally responsible methods.
Our initial focus will be on three high-priority invasive plant species:
- Himalayan Balsam (Impatiens glandulifera)
- Giant Rhubarb (Gunnera tinctoria)
- American Skunk Cabbage (Lysichiton americanus)
Strategic Objectives
Over the next five years we will:
- Map and monitor the distribution of invasive species throughout the catchment.
- Prioritise areas where control measures will deliver the greatest environmental benefit.
- Coordinate volunteer-led control programmes where appropriate.
- Work with landowners to secure access and long-term management agreements.
- Promote biosecurity through the Check, Clean, Dry campaign.
- Raise awareness of invasive species and their impacts.
- Develop partnerships to secure funding and deliver catchment-scale control programmes.
- Monitor the effectiveness of control measures and adapt management approaches where required.
Himalayan Balsam Strategy
Background
Himalayan balsam is widespread along many river corridors throughout Ireland. It spreads rapidly through explosive seed dispersal and can dominate riverbanks, shading out native vegetation.
When the plant dies back during winter it leaves bare soil exposed, increasing erosion and sediment inputs to watercourses.
Management Approach
The Trust will adopt a catchment-scale control programme focused on:
- Mapping infestations and identifying source populations.
- Prioritising upstream areas to prevent recolonisation.
- Organising annual volunteer balsam bashes.
- Hand-pulling plants before seed production.
- Monitoring treated sites annually.
- Supporting landowners with advice and practical assistance.
Desired Outcome
Progressive reduction of Himalayan balsam populations throughout priority river corridors and the recovery of native riparian vegetation.
Giant Rhubarb Strategy
Background
Giant rhubarb forms dense stands that suppress native vegetation and alter natural habitats. It spreads through both seed production and vegetative growth and can rapidly colonise riverbanks, wetlands and disturbed ground.
Management Approach
The Trust will:
- Identify and map all known infestations.
- Prioritise isolated populations for rapid control.
- Work with landowners to implement long-term control measures.
- Employ appropriate chemical treatment by trained and licensed operators where required.
- Monitor sites for regrowth and seedling establishment.
- Coordinate control efforts across neighbouring landholdings.
Giant Rhubarb can remain a problem long after the visible plants have been removed, with seeds capable of surviving in the soil for up to eight years. Ongoing monitoring is therefore essential, and flowering stems must be removed before they set seed during the summer months. Through continued management and follow-up visits, we aim to gradually reduce and ultimately eradicate infestations from the catchment.
Desired Outcome
Containment and gradual eradication of giant rhubarb from priority sites, reducing its spread into sensitive habitats and watercourses.
American Skunk Cabbage Strategy
Background
American skunk cabbage is an emerging invasive species capable of colonising wetlands, marshes and riparian habitats. Once established it can form dense monocultures that displace native wetland vegetation and alter habitat structure.
Early intervention offers the greatest opportunity for successful control.
Management Approach
The Trust will:
- Identify and verify all known populations.
- Prioritise early detection and rapid response.
- Work with landowners and statutory agencies to coordinate management.
- Remove isolated plants before further spread occurs.
- Monitor sites regularly for seedlings and regrowth.
- Raise awareness amongst local communities and landowners to encourage reporting of new occurrences.
The Trust carried out its first American Skunk Cabbage control works in June 2026. The project highlighted the challenges of managing this species, which often grows in wet and boggy habitats. In some locations, excavation to depths of up to one metre was required to remove the entire root. Follow-up visits are planned for early 2027, when surrounding vegetation levels are lower, allowing easier access to known infestation sites and more effective control of any remaining plants.
Desired Outcome
Prevent the establishment and spread of American skunk cabbage within the Sligo Bay Catchment and eradicate isolated populations wherever feasible.
Community Engagement
Community participation is essential to the success of invasive species management. The Trust will continue to:
- Deliver volunteer control events.
- Provide training and educational opportunities.
- Work with schools and community groups.
- Promote citizen science recording.
- Encourage responsible biosecurity practices.
Biosecurity
All staff, volunteers and contractors working on behalf of the Trust will follow the principles of:
Check, Clean, Dry
- Check equipment and clothing for plant material and mud.
- Clean equipment thoroughly before leaving site.
- Dry equipment fully before visiting another waterbody.
Strong biosecurity practices help prevent the accidental spread of invasive species between sites.
Measuring Success
Success will be assessed through:
- Area of invasive species treated.
- Number of volunteer events delivered.
- Number of volunteers engaged.
- Length of river corridor restored.
- Reduction in invasive species cover.
- Recovery of native vegetation.
- New infestations identified and controlled.
By working together with communities, landowners and partner organisations, the Sligo Bay Catchment Rivers Trust aims to create healthier rivers, wetlands and riparian habitats that are more resilient to invasive species and better able to support wildlife and local communities for generations to come.