First record of non-native Yoldia limatula (Say, 1831) in the United Kingdom: evidence of a newly established population (Bivalvia: Protobranchia)

Abstract

This paper reports the first recorded presence of a non-native protobranch bivalve, Yoldia limatula (American file clam), in the United Kingdom. In November 2020, it was found to be present in already high numbers (257 individuals recorded) in subtidal sediments in the estuarine zone of the Tees River, Northeast England. This record is far outside the species’ native range of North America. The species has recently also been found on the continental margin of Northwest Europe. It is likely to have been introduced into the UK via marine traffic, with larval displacement through ballast water exchange thought the most likely route of entry. The bioturbating activities of the species in its native range are discussed, which might have significant ecosystem implications if the species were to become fully established in UK waters. An identification guide to separate this species from similar species of protobranch bivalves in the UK is included.