And it\u2019s not just plants. The arrival of breeding colonies of the Asian hornet in 2025 gained wide media attention and a rapid response from authorities. But the number of new species arriving on our shores is remarkable. The autumn 2025 newsletter from the National Biodiversity Data Centre<\/a> gives a taste, listing new sightings of freshwater turtles, short-tailed field voles (a common European rodent), roe deer and even a variated squirrel (a native of the Americas) as well as several exotic plants. <\/p>\n While the centre provides an early warning system for the arrival of invasive \u2013 or potentially invasive \u2013 species, the system for managing the response to these species is confused. Definitions for what actually constitutes an invasive species vary, but typically emphasise the potential harm that they can do native biodiversity and\/or the economy. But therein lies a fatal tension. <\/p>\n Whole industries \u2013 not only garden centres and pet shops, but agriculture and forestry \u2013 rely on plants and animals that are exotic to our native ecosystems. Some of these cause tremendous ecological harm, such as sheep, goats or Sitka spruce, but are rarely thought of as invasive species. <\/p>\n In fact the Sitka spruce was identified by the Botanical Society of Britain and Ireland, in their monumental Plant Atlas 2020, as the plant with the greatest increase in distribution of any plant over the past 100 years. The authors pointed to the plant\u2019s \u201cinvasive tendency\u201d, noting that \u201cit regenerates freely from seed, often on heathland and bog some distance away from plantations\u201d. Yet the National Biodiversity Data Centre classifies it as \u201clow risk of impact\u201d. <\/p>\n Cherry laurel, which is a very frequent hedging plant, and distinctive with its shiny green leaves, is a native of Turkey\u2019s Black Sea region and has infested swathes of broadleaved woodland in Ireland, particularly in the east and south. The centre labels it \u201cinvasive \u2013 risk of high impact\u201d while the Citizens\u2019 Assembly on biodiversity<\/a> loss in 2023 recommended that the state should \u201cact immediately\u201d in banning its sale. <\/p>\n Yet it is not listed in legislation for this purpose and remains widely available in garden centres. \u201cThere\u2019s no buy-in from the horticulture industry for this move,\u201d says Smyth. \u201cThere\u2019s so much of it being grown and supplied.\u201d <\/p>\n The wild boar is considered by many ecologists to be as native a species as any, although proving this is difficult (as it is for many animals where debates rage as to their origins). In a risk assessment led by the biodiversity centre in 2014 it was acknowledged that this archaeological history was \u201ccomplicated\u201d. <\/p>\n Wild boar are important components of forest ecosystems in Europe and Asia and have been shown to be beneficial to biodiversity. However, the risk assessment noted the potential for \u201cmajor\u201d economic losses due to crop damage and the potential for disease transmission. The animal has been listed as an invasive species in law since 2011. <\/p>\n There are many other exotic plants and animals that worry ecologists due to the impacts that are seen to native vegetation or wildlife. Pheasants, which originated in Asia, will wipe out local lizard populations and compete with ground-nesting birds such as corncrakes. <\/p>\n Pacific oysters could proliferate and supplant areas of sea floor that were traditionally composed of native flat oysters. Fuchsia and montbretia (also called Crocosmia) will take over whole roadsides where once there were native hedgerows. But all of these species have been assessed by the National Biodiversity Data Centre as \u201clow risk\u201d or have not been assessed at all. <\/p>\n Smyth says Ireland reacts more to edicts from the EU rather than developing its own system of assessment and management. In 2024 new legislation was passed to align with EU regulations \u201con the prevention and management of the introduction and spread of invasive alien species\u201d. As well as many well-established weeds such as rhododendron and Japanese knotgrass, this law, for the first time, lists two of our most common deer species: fallow deer (well known from the Phoenix Park in Dublin) and Sika deer (an Asian introduction) but, confusingly, both remain protected species in the Wildlife Act. <\/p>\n [\u00a0\u2018I think I see Japanese knotweed growing next door. What should I do?\u2019Opens in new window<\/a>\u00a0]<\/p>\n Identifying alien invasive species is one thing, and while the biodiversity centre performs a valuable task in monitoring and alerting authorities, it is not always clear whose job it is to enforce regulations or to carry out what might be difficult or expensive eradication programmes. The regulation says that it will be an offence to keep a species listed in law but it is hard to know the meaning of this given the number of invasive species, even on public lands such as parks or Coillte<\/a> forests. <\/p>\n The new law is roundly welcomed in providing the tools necessary to prevent the sale and transport of proscribed species but, as of November 2025, there have been no enforcement actions by the responsible department \u2013 the Department of Heritage<\/a>. <\/p>\n Collette O\u2019Flynn, the invasive species officer with the National Biodiversity Data Centre, says their role is to receive and verify sightings and to make that information available as well as to assess whether non-native species are at risk of causing an impact, and determining what that impact is. <\/p>\n![\"Wild](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/02\/O5CPQWNNDZSYVM2BEA4LIL7PCU.jpg\")
Wild boar in Kerry. Photograph: Radio Kerry <\/p>\n