Solieria chordalis
Date of introduction and origin
Solieria chordalis was introduced around 1976 from
northern France into Falmouth Harbour (Cornwall), and the Fleet and
Weymouth Bay (Dorest) (Farnham & Jephson 1977).
Method of introduction
It was possibly transported on ships' hulls (Farnham 1980),
although perhaps also on ballast stones in recent historical times.
Weed-rafting of stones may also have been a natural mechanism for
dispersal across the Channel (W.F. Farnham pers. comm.).
Reasons for success
It spreads using vegetative regeneration from basal, rhizoidal
systems. (indeed no fertile gametophytes have been found), so
despite lack of sexual reproduction, the asexual methods are very
effective.
Rate of spread and methods involved
It has spread slowly. A disjunct distribution is suggestive of
remote dispersal methods such as shipping (Farnham 1980).
Distribution
Currently it is found in western Wales, Dorset and Cornwall
(Hiscock & Maggs 1984). Elsewhere in Europe it is found in
France (Farnham 1980), Spain and in the western Mediterranean
(South & Tittley 1986; I. Tittley, pers. comm.).
Factors likely to influence spread and distribution
Unknown.
Effects on the environment
None known.
Effects on commercial interests
Unknown.
Control methods used and effectiveness
None used.
Beneficial effects
It could be cultivated to produce carrageenan.
Comments
Previously it was considered that, as well as Solieria
chordalis on the south coast, Solieria filiformis was
present in Milford Haven, South Wales. However, W.F. Farnham (pers.
comm.) indicates that the Milford Haven population (Farnham 1980;
Farnham & Irvine 1979) was misidentified and is probably better
referred to as S. chordalis (the only known species of
this genus in Britain).
References
Farnham, W.F. 1980. Studies on aliens in the marine flora of
southern England. In: The shore environment, volume 2:
ecosystems, ed. by J.H. Price, D.E.G. Irvine & W.F.
Farnham, 875-914. London, Academic Press. (Systematics Association
Special Volume, No. 17B.)
Farnham, W.F., & Irvine, L.M. 1979. Discovery of members
of the red algal family Solieriaceae in the British Isles.
British Phycological Journal, 14: 123.
Farnham, W.F., & Jephson, N.A. 1977. A survey of the maerl
beds of Falmouth (Cornwall). British Phycological Journal,
12: 119.
Hiscock, S. 1986. A field guide to the British Red
Seaweeds. Field Studies Guide. Ocassional Publication
13.
Hiscock, S., & Maggs, C.A. 1984. Notes on the distribution
and ecology of some new and interesting seaweeds from south-west
Britain. British Phycological Journal, 19:
73-87.
South, G.R., & Tittley, I. 1986. A checklist and
distributional index of the benthic marine algae of the North
Atlantic Ocean. St. Andrews & London, Huntsman Marine
Laboratory & British Museum (Natural History).
Acknowledgements (contributions from questionnaire)
Dr C.A. Maggs, Queen's University of Belfast.
Dr W.F. Farnham, University of Portsmouth.
Mr I. Tittley, Natural History Museum, London.