THE OCCURRENCE OF UNDARIA-PINNATIFIDA (PHAEOPHYCEAE, LAMINARIALES) ON THE SOUTH COAST OF ENGLAND

A mature population of the kelp Undaria pinnatifida (Phaeophyceae, Laminariales) has been found attached to floating pontoons in the Solent region of the south coast of England. This is the first record of its occurrence in the British Isles. It seems most probable that the plants originated from Brittany, where the species was deliberately introduced in 1983 for cultivation purposes, and that small boats were the cross-channel vector. Its likely further spread in the North Atlantic, and the ensuing ecological consequences, are discussed in the light of recent observations on 'escaped' subtidal populations in Brittany and its well-documented introduction into New Zealand and Tasmanian waters.