Many plants and animals have been introduced into Northern Ireland from all over the world through a variety of pathways (see below). These are known as non-native species. Most non-native species do not cause problems, and some are even economically important to Northern Ireland. However, around 10-15% of these non-native species go on to spread and become invasive non-native species.
The focus of Invasive Species Northern Ireland is invasive species. These are species that have been introduced through human activity (accidentally or deliberately) or naturally, and have negative impacts on our wildlife and the environment, our economy, and our society. After habitat loss, invasive species are the second biggest threat to biodiversity worldwide, and the biggest threat to biodiversity on islands.
How do invasive species get here?
Invasive species can be introduced both intentionally and unintentionally through a variety of pathways. The Convention on Biological Diversity (CBD) has a standardised system for categorising these pathways of introduction, which you read more about here. We have listed some of these pathways below:
- Shipping
-
- Hull fouling
- Hitchhikers and stowaways imported with cargo and packing material
- Discharge of ballast water
- Escape from captivity
-
- Escape or accidental/deliberate release of pet/aquarium/terrarium species and associated live food
- Horticulture
-
- Non-native garden plants can ‘jump the fence’ and go on to become invasive in the environment
- Improper disposal of garden waste and pond plants
- Hitchhikers and stowaways brought in alongside imported plant species, soil and growth mediums
- Natural pathways
-
- With climate change, increased temperatures can allow invasive species to expand their range into areas that were once cooler
- Strong winds and ocean currents
- Migrating species can carry hitchhikers
- Recreational boating
-
- Hull fouling
- Moved from site to site on equipment such as anchors, trailers and ropes, and in bilge water
- Recreational angling
-
- Invasive species can be brought in on equipment used abroad
- Spread from site to site on equipment and clothing
- Deliberate release of fish species
- Deliberate or accidental release of live bait species
- Aquaculture
-
- Imported aquaculture product can contain hitchhiking invasive species
- Transported equipment can carry invasive species from one site to another
- Released into Nature
-
- Biological controls
- For erosion control e.g. dune stabilisation
- Game animals (for fishing or hunting)
What impacts do they have?
Environmental
Ecosystems provide a variety of services to us for free and these bring many benefits to society and the economy. There are four main categories of services:
- Provisioning, such as the production of food and water
- Regulating, which includes the control of climate and disease
- Supporting, for example, nutrient cycling and crop pollination
- Cultural, such as spiritual and recreational benefits
Invasive species can impact on the ability of nature to provide these services resulting in increased economic costs and environmental damage.
The impacts of invasive species on biodiversity are widely demonstrated and can occur in all habitats.
For example:
- Outcompeting native species for resources
- Reducing native biodiversity by grazing on native flora
- Predation on native species and their young
- Altering habitats which can lead to flooding
- Introduction of parasites and pathogens which were not previously found here and against which our native species are not adapted to cope
- Dilution of native gene pools by interbreeding with native species
Economic
The introduction and subsequent spread of invasive species can have negative economic impacts on a variety of sectors including agriculture, forestry, fishing, tourism and transport.
A report assessing the direct costs of invasive species to the UK was published in 2023 and can be found here. A summary of the findings can be found below:
- The estimated annual cost of invasive species to the Northern Ireland economy in 2021 was £150 million
- The estimated annual cost of invasive species to the UK economy in 2021 was £4014 million
- The largest fraction of cost was allocated to agriculture, followed by forestry
Social
As well as having impacts on the environment and the economy, invasive species may impact on our society, health, and way of life. There are a wide range of activities than can unintentionally spread invasive species such as gardening, boating, angling and the keeping and trade of pets.
Invasive species have the potential to disrupt these activities as they transform the environment around us. For example:
- Invasive plants can take over a garden and spread into neighbouring properties
- Invasive plants can prevent angling and access to rivers and lakes
- Invasive species can restrict boating by interfering with navigation and colonising boat hulls and marinas
- Pets can escape and become established in the wild
- Some invasive species spread disease, some can cause skin irritation and others can affect our respiratory system
Advice on how you can prevent the spread of invasive species is available here.
Now that you understand some of the impacts invasive species can have, why not see how you can help stop their introduction and spread?
Learn how to ID invasive species
|
Send in records for the invasive species you have identified
|
Learn what you can do to prevent invasive species spreading |
Learn more:
Many plants and animals have been introduced into Northern Ireland from all over the world through a variety of pathways (see below). These are known as non-native species. Most non-native species do not cause problems, and some are even economically important to Northern Ireland. However, around 10-15% of these non-native species go on to spread and become invasive non-native species.
The focus of Invasive Species Northern Ireland is invasive species. These are species that have been introduced through human activity (accidentally or deliberately) or naturally, and have negative impacts on our wildlife and the environment, our economy, and our society. After habitat loss, invasive species are the second biggest threat to biodiversity worldwide, and the biggest threat to biodiversity on islands.
How do invasive species get here?
Invasive species can be introduced both intentionally and unintentionally through a variety of pathways. The Convention on Biological Diversity (CBD) has a standardised system for categorising these pathways of introduction, which you read more about here. We have listed some of these pathways below:
- Shipping
-
- Hull fouling
- Hitchhikers and stowaways imported with cargo and packing material
- Discharge of ballast water
- Escape from captivity
-
- Escape or accidental/deliberate release of pet/aquarium/terrarium species and associated live food
- Horticulture
-
- Non-native garden plants can ‘jump the fence’ and go on to become invasive in the environment
- Improper disposal of garden waste and pond plants
- Hitchhikers and stowaways brought in alongside imported plant species, soil and growth mediums
- Natural pathways
-
- With climate change, increased temperatures can allow invasive species to expand their range into areas that were once cooler
- Strong winds and ocean currents
- Migrating species can carry hitchhikers
- Recreational boating
-
- Hull fouling
- Moved from site to site on equipment such as anchors, trailers and ropes, and in bilge water
- Recreational angling
-
- Invasive species can be brought in on equipment used abroad
- Spread from site to site on equipment and clothing
- Deliberate release of fish species
- Deliberate or accidental release of live bait species
- Aquaculture
-
- Imported aquaculture product can contain hitchhiking invasive species
- Transported equipment can carry invasive species from one site to another
- Released into Nature
-
- Biological controls
- For erosion control e.g. dune stabilisation
- Game animals (for fishing or hunting)
What impacts do they have?
Environmental
Ecosystems provide a variety of services to us for free and these bring many benefits to society and the economy. There are four main categories of services:
- Provisioning, such as the production of food and water
- Regulating, which includes the control of climate and disease
- Supporting, for example, nutrient cycling and crop pollination
- Cultural, such as spiritual and recreational benefits
Invasive species can impact on the ability of nature to provide these services resulting in increased economic costs and environmental damage.
The impacts of invasive species on biodiversity are widely demonstrated and can occur in all habitats.
For example:
- Outcompeting native species for resources
- Reducing native biodiversity by grazing on native flora
- Predation on native species and their young
- Altering habitats which can lead to flooding
- Introduction of parasites and pathogens which were not previously found here and against which our native species are not adapted to cope
- Dilution of native gene pools by interbreeding with native species
Economic
The introduction and subsequent spread of invasive species can have negative economic impacts on a variety of sectors including agriculture, forestry, fishing, tourism and transport.
A report assessing the direct costs of invasive species to the UK was published in 2023 and can be found here. A summary of the findings can be found below:
- The estimated annual cost of invasive species to the Northern Ireland economy in 2021 was £150 million
- The estimated annual cost of invasive species to the UK economy in 2021 was £4014 million
- The largest fraction of cost was allocated to agriculture, followed by forestry
Social
As well as having impacts on the environment and the economy, invasive species may impact on our society, health, and way of life. There are a wide range of activities than can unintentionally spread invasive species such as gardening, boating, angling and the keeping and trade of pets.
Invasive species have the potential to disrupt these activities as they transform the environment around us. For example:
- Invasive plants can take over a garden and spread into neighbouring properties
- Invasive plants can prevent angling and access to rivers and lakes
- Invasive species can restrict boating by interfering with navigation and colonising boat hulls and marinas
- Pets can escape and become established in the wild
- Some invasive species spread disease, some can cause skin irritation and others can affect our respiratory system
Advice on how you can prevent the spread of invasive species is available here.
Now that you understand some of the impacts invasive species can have, why not see how you can help stop their introduction and spread?
Learn how to ID invasive species
|
Send in records for the invasive species you have identified
|
Learn what you can do to prevent invasive species spreading |
Learn more:
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