Date of introduction and origin
Asparagopsis armata was first recorded in 1949 on
Lundy in the Bristol Channel. The Falkenbergia phase was
recorded by Harvey & Drew (1949); the gametangial condition of
Asparagopsis armata was first recorded from
Cornwall by Drew (1950). It had been introduced from mainland
Europe. It was first recorded in Ireland in 1939 (Valéra 1942). The
species originates from Australia and/or possibly New
Zealand.
Method of introduction
It was introduced to mainland Europe, possibly as an
associated unintentional introduction with oysters (it was first
recorded in Algeria in 1923) (Feldman & Feldman 1942), then
probably introduced to Britain and Ireland by rafting and
floating.
Reasons for success
The species has a lack of predators and a rapid growth rate.
It is also an opportunist.
Rate of spread and methods involved
The species was present in Ireland in 1939, Lundy in 1949,
Plymouth (Devon) in 1950, Start Point (south Devon) in 1953 and the
Solent in 1973, and arrived in Shetland by 1973 (Irvine et
al. 1975).
Distribution
It is distributed throughout the British Isles although
uncommon on the east coast (Irvine et al. 1975). European
populations can be found from the western Mediterranean to Shetland
and it is especially common on the coast of Spain (South &
Tittley 1986).
Factors likely to influence spread and distribution
Lethal temperatures and temperature required for reproduction
are likely to restrict distribution. The hooked branches are likely
to spread by attachment onto floating objects (Farnham 1980).
Effects on the environment
Unknown.
Effects on commercial interests
Unknown.
Control methods used and effectiveness
None used.
Beneficial effects
None known.
Comments
There are two macroscopic phases to the life cycle of
Asparagopsis armata, the filamentous habit being very
similar in appearance to that of Bonnemaisonia hamifera
but readily distinguished at the cellular level (D.A. Birkett pers.
comm.).
References
Drew, K.M. 1950. Occurrence of Asparagopsis armata
Harv. on the coast of Cornwall. Nature, 166:
873-874.
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.)
Feldmann, J., & Feldmann, G. 1942. Récherches sur les
Bonnemaisoniacées et leur alternances de générations.
Annales de Science Naturelle (Botanie) Sér II, 3:
75-175.
Harvey, C.C., & Drew, K.M. 1949. Occurrence of
Falkenbergia on the English coast. Nature, 164:
542-543.
Hiscock, S. 1986. A field guide to the British Red
Seaweeds. Field Studies Guide. Ocassional Publication
13.
Irvine, D.E.G., Guiry, M.D., Tittley, I., & Russell, G.
1975. New and interesting marine algae from the Shetland Isles.
British Phycological Journal, 10:
57-71.
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).
Valéra, M. de. 1942. A red alga new to Ireland:
Asparagopsis armata Harvey on the west coast. Irish
Naturalists' Journal, 8: 30.
Acknowledgements (contributions from questionnaire)
Mr I. Tittley, Natural History Museum, London.