The distribution of the Asian clam Corbicula fluminea and its potential to spread in Ireland

Dan Minchin

doi:10.3391/mbi.2014.5.2.10

Abstract

The Asian clam Corbicula fluminea was first recorded from the Barrow River in Ireland in April 2010. There are five separate concentrations known to exist. Four of these were found during 2010 to 2012 within Ireland’s largest river, the Shannon. The abundance and polymodal length frequencies indicate that the likely seminal site in Ireland is from the Barrow where it may have been present since, or before, 2006. There is a concern the species will continue to expand and modify aquatic communities. All concentrations are linked by a connected navigation system thereby implicating leisure craft as a pathway. However, anglers might be spreading the species since most sites where they are now known are associated with angling. This account reviews the evidence for these potential pathways, for this ‘r’ strategist. The abundance and distribution in the lower Shannon River, and possible impacts on lake ecosystems are discussed.

Highlights

Invasions of non-indigenous species (NIS) are acknowledged as one of the major threats to natural environments - terrestrial, freshwater and marine - having ecological, economic and social consequences
When dealing with the international agreements and measures to prevent introduction of marine Invasive Alien Species (IAS), the following documents are fundamental to the conservation and management of the marine environment: the International Convention for the Control and Management of Ships' Ballast Water and Sediments (IMO 2004), ICES Code of Practice on the Introductions and Transfers of Marine Organisms (ICES 2005), Alien Species in Aquaculture - IUCN considerations for responsible use (Hewitt et al 2006), EC Regulation on concerning use of alien and locally absent species in aquaculture (European Commission 2007) and EC Marine Strategy Framework Directive (European Commission 2008)
A recent study of diatoms and dinoflagellates reported as NIS in European Seas found dubious identifications, and that synonyms were included as separate species (Gómez 2008)

Summary

Introduction

Invasions of non-indigenous species (NIS) are acknowledged as one of the major threats to natural environments - terrestrial, freshwater and marine - having ecological, economic and social consequences. A recently published Proposal for a Regulation of the European Parliament and of the Council on the prevention and management of the introduction and spread of invasive alien species (European Commission 2013) states that “...The impact of IAS on biodiversity is significant ... The EU Biodiversity Strategy (European Commission 2011) aims that "...by 2020, Invasive Alien Species (IAS) and their pathways are identified and prioritised, priority species are controlled or eradicated, and pathways are managed to prevent the introduction and establishment of new IAS...". Stemming from a recent freshwater invasives conference, Caffrey et al (2014) identified ’the top 20 issues that relate to IAS management in Europe“. We agree and support all the issues proposed, and would like to contribute to this important initiative by adding six important topics that relate to the marine environment

Regulatory framework to prevent introduction of IAS

Reliable NIS identifications and loss of taxonomic expertise

Data-gaps impede comprehensive assessments

Need for a unified and appropriate terminology

Standardization of data and information systems

Conclusions