Balanus amphitrite
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
Unknown.
Distribution
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
Unknown.
Effects on commercial interests
It is a fouling organism.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
References
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.