Balanus amphitrite

Phylum: Crustacea
Class: Maxillopoda
Order: Thoracica
Species name: Balanus amphitrite Darwin 1854
Synonyms: None
Common name: None
Date of introduction and origin
Balanus amphitrite was found in 1937 in Shoreham Harbour, Sussex (Bishop 1950). This barnacle is tropical. On the basis of fossil records, it is considered to be native to the southwestern Pacific and Indian Oceans, and to have been introduced to the North Pacific and Atlantic Oceans, for which no fossil records exist.
Method of introduction
It may have been transported to Britain in the adult stage as a fouling organisms on ships' hulls, or the pelagic larvae may have travelled in ballast water.
Reasons for success
Its establishment may have been helped by warm waters from power stations.
Rate of spread and methods involved
Populations have been found in southern England, southern Wales and throughout European countries south of Britain. Balanus amphitrite has also been recorded from Shetland in 1988 although a breeding population is apparently not established there (S.M. Smith pers. comm.).
Factors likely to influence spread and distribution
Temperatures further north than southern England are too low for reproduction. It is at its northern limit in southern Britain.
Effects on the environment
Effects on commercial interests
It is a fouling organism.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
Bishop, M.W.H. 1950. Distribution of Balanus amphitrite Darwin var. denticulata (Broch). Nature, 165: 409.
Hayward, P.J., & Ryland, J.S., eds. 1990. The marine fauna of the British Isles and north-west Europe. 2 vols. Oxford, Clarendon Press.
Acknowledgements (contributions from questionnaire)
Dr M. Barnes, Dunstaffnage Marine Laboratory.