DAERA urges greater vigilance as Quagga mussel confirmed in Lower Lough Erne – first confirmed record in Northern Ireland

Date published: 15 December 2025

Scientists from the Agri-Food and Biosciences Institute (AFBI) collected samples suspected to be quagga mussels (Dreissena rostriformis bugensis) while carrying out routine surveys in Lower Lough Erne.

This was confirmed on 10 December following DNA analysis at Queen’s University Belfast.

The quagga mussel is a small bivalve mollusc similar to the invasive non-native zebra mussel. Like the now widespread zebra mussel, the species originates from the Ponto-Caspian region - an area around the Black and Caspian Seas.

It is highly invasive and has spread rapidly from its native region in Ukraine during the last few decades through Western Europe and to North America and Mexico.

It was first recorded in Britain in 2014 and in Loughs Ree and Derg (Ireland) and in the main River Shannon system, in 2021.

Compared with zebra mussels, quagga occupy a wider range of depths, they colonise softer substrates and have higher filtration rates. It is expected they will survive in some places that zebra mussel can't and will eventually outcompete and displace them.

Possible vectors include recreational boating, angling traffic, trailered craft travelling overland and inter-catchment transfer of equipment such as paddle boards/canoes.

DAERA Minister Andrew Muir said: “This confirmation that the highly invasive Quagga mussel has arrived in  Northern Ireland represents another significant pressure to our already beleaguered freshwater system.

“Increased vigilance and surveillance is critical.  My officials are engaging with stakeholders and public agencies to alert them to this arrival and the need for enhanced biosecurity measures.  Cross-border engagement also continues through the Shared Island Biosecurity and Invasive Species Initiative.” 

Rose Muir, NIEA Invasive Non Native Species team added: “There is no effective control or eradication method for quagga mussel once it has established in a water body.  The best method of slowing the spread and reducing the risk to other water bodies is by applying better biosecurity through the Check, Clean, Dry approach. We are urging all water users to follow this protocol strictly when moving between water bodies.”

Dr Kevin Gallagher, Senior Scientific Officer at the Agri-Food and Biosciences Institute (AFBI) said: “The confirmation of quagga mussel in Lower Lough Erne is significant given the connectivity of major water bodies. Once established, this species can spread rapidly and cause substantial ecological and economic impacts, including altered food webs and infrastructure fouling. This underlines the need for enhanced surveillance across connected systems, including Lough Neagh, and strict biosecurity to limit further spread.”

With quagga now confirmed in both the Shannon system and Lower Lough Erne, the most likely scenario is that there has been a connected invasion along the Shannon–Erne corridor.  It is therefore plausible that quagga are already present but undetected in intermediate waterbodies, including Upper Lough Erne.

The Department has contacted relevant stakeholders to make them aware of the new arrival and our response to it and will initiate extra monitoring to investigate the extent of the population.

Officials are planning to identify those waters that should also be sampled by assessing the potential pathways for the spread of quagga mussels into other water bodies.