This designation was controversial, and the taxonomic status of the Nore pearl mussel remains inconclusive.

[2] The species is native to the Three Sisters - the rivers Barrow, Suir and Nore, the latter of which being the mussel's namesake.

The Nore pearl mussel also has a significantly shorter lifespan than M. margaritifera, typically living for 60 to 80 years.

Studies conducted on Nore pearl mussel distribution revealed that the population of the species had declined by approximately 75% between 1991 and 2009.

The primary pressure identified was agricultural intensification leading to elevated levels of phosphorus, nitrate and suspended solids across the mussel's native range.