Open Atlantic Coast of Europe — A Century of Introduced Species into French Waters

Abstract

This paper aims to establish a comprehensive list of exotic species introduced into Atlantic French waters over the last century as well as their origin, and the vectors involved in the process. At least 104 nonindigenous species have been recorded in the Atlantic and Channel coastal waters. Among those species, only a few (Bonamia ostreae, Crepidula fornicata) have resulted in highly significant negative impacts and side-effects on the coastal activity. In contrast, the introduction of the Japanese oyster Crassostrea gigas can be considered to be successful, sustaining a large industry counting more than 4,000 companies and 150,000 tons of yearly production. Over the last decade, French and European laws have strenghtened the controls over exotic species introductions, limiting their impacts. These new regulations and increased awareness from the scientific community with regard to coastal industry and biodiversity have reduced significantly the cases of deliberate introduction, while the risk analysis requirement has improved the overall management. However, in spite of these improvements, cases remain significant, mostly by accidental and/or increased vectors of introduction such as the ballast waters and sediment. Moreover, global changes should now be considered as a major issue, likely inducing future geographic distribution changes over a large European coastal range. Understanding the invasion population dynamics for exotic species remains a challenging research issue currently addressed by the French INVABIO multidisciplinary program.