EcoEireann > What We Do > Protected Species & Habitat Surveys > Fresh Water Pearl Mussel

Fresh Water Pearl Mussel

fresh water pearl muscles, fresh water pearl muscles surveys


There are two species of freshwater pearl mussel considered in Ireland. The freshwater pearl mussel (Margaritifera margaritifera) and the Irish, or Nore, freshwater pearl mussel (Margaritifera durrovensis) which is found in hard water and restricted to the Rivers Barrow and Nore. Genetic diversity testing is ongoing for the latter species.

Both species receive protection under the following legislation:

  • The Wildlife Acts, 1976 and 2000
  • Annex V of the Habitats Directive

Ireland’s freshwater systems are also regulated through:

  • European Communities (Water Policy) Regulations 2003

Designated sites

There are 19 sites in Ireland which have been designated for freshwater pearl mussel. The sites identified by statutory agencies are of international importance and have been designated as Special Areas of Conservation (SAC) as required by the EU Habitats Directive.

When do I need to get in touch?

If your project is to affect a waterway it should always be assessed for protected species and for any effects to freshwater species, such as FWPM, fish or white-clawed crayfish. Consideration of the presence of FWPM populations and their life stage can have significant implications regarding;

  • Project design
  • Consenting requirements
  • Project program (potential for significant seasonal restrictions)
  • Pollution control and monitoring
  • Working methods

We recommend consideration of potential implications on FWPM at an early stage in project development where the proposed site may have direct or indirect hydrological links to a site designated for this species.

How can EcoÉireann Help Me?

We use our extensive experience of informing and overseeing works in freshwater environments to advise on project requirements. Where FWPM surveys are required, EcoÉireann can obtain a licence from NPWS to undertake surveys.

We apply best practice guidelines, in-depth knowledge of Irish ecology and habitat requirements. We then present the results in our detailed professional reports to inform and support your project planning application or other consenting process.