The EU's first ever pests blacklist came into force last week.
Featuring on the list of 37 "invasive alien species" is the North American grey squirrel, scourge of Irish foresters and existential threat to the indigenous red squirrel.
Also problematic for Ireland is the curly waterweed, an aquatic plant originating in South Africa that harms fish and impedes drainage.
The floating weed has made certain parts of Lough Corrib impassable for boats and fishermen, says Ciarán O'Keeffe, a scientist and principal officer at the Department of Arts, Heritage, Regional, Rural and Gaeltacht Affairs.
"Our main objective is to contain the risk of [these species] spreading to another member state," Mr O'Keeffe said.
The grey squirrel is already widespread in the UK and has wiped out the red squirrel in certain areas.
The EU says invasive species wreak damages of up to €12bn a year on property, crops and livelihoods and need to be stopped from entering EU countries or, if already present, to be kept under control.
The rules do not require the culling of animals, who are allowed to live out their lives in zoos, as long as they don't reproduce or escape.
The Commission has shied away from requiring total eradication - unlike New Zealand, which has set a 2050 deadline for getting rid of rats, stoats and possums - saying it would be "disproportionate and costly".
Mr O'Keeffe says the Department is trying to get a handle on the number of grey squirrels and whether it can rely on natural predators - such as the pine marten, a stoat-like mammal indigenous to Ireland - to help reduce the squirrel population.
Controlling the spread of curly waterweed (in Latin Lagarosiphon) will be more difficult as it is able to root itself even in deep waters.
Also of concern for Irish environmentalists are seven other species on the EU list: one garden plant and two types of water weed, a species of duck, a turtle known as the red-eared slider, a small forest deer and a type of crab.
All 37 species on the EU list are now subject to import, keeping, breeding and sales restrictions.
Listed species present in the rest of Europe include the North American bullfrog, the raccoon, the Siberian chipmunk and several types of crayfish.
EU countries have until June 2019 to draw up surveillance and management plans and take action to contain or reduce the blacklisted species.
A failure to comply with the rules could result in eventual prosecution and fines in the EU's top court.
The list will be constantly updated. The next round of species could be added as early as spring next year, and is likely to include Nuttall's pondweed, which is present in Lough Erne.
The EU has set up a new panel to tackle food waste, which it says amounts to around 88 million tonnes a year and costs an estimated €143bn.
The EU — and its 28 member states — last year signed up to the 17 UN sustainable development goals, one of which is to halve per capita food waste at the retail and consumer level by 2030.
Households, restaurants and supermarkets make up the largest proportion of food waste in the EU (70pc), with the production and processing sectors contributing 30pc.
The EU’s food waste panel, which is made up of government representatives, NGOs, researchers, business groups, the UN’s food and environmental panels and the OECD, will meet for the first time on November 29 in Brussels.