Journal of Applied Phycology

, Volume 20, Issue 5, pp 825–832 | Cite as

Sargassum muticum (Yendo) Fensholt in Ireland: an invasive species on the move

  • Stefan KraanEmail author


The invasive marine macroalga Sargassum muticum was recorded from Kilmore Quay, Co. Waterford, for the first time in the Republic of Ireland in 2001. It was found at several other places in that year and in subsequent years. An intensive survey was carried out from April 2003 to November 2003 to map the geographical distribution and spread of this invasive brown macroalga, and data on distribution were collected in subsequent years through 2006. This study indicated that S. muticum most probably arrived in the early or mid 1990s and has spread all around the Irish coastline colonising Co. Donegal for the first time in 2006. The results indicate that spreading is facilitated by boating and perhaps via shellfish transport. A rough rate of spread of 2–3 km year−1 has been calculated within one bay and for the Irish coastline of about 54 km year−1. Observations showed that S. muticum has been found growing in seagrass beds and in rock pools, which might have serious consequences for the biodiversity in rock pools and for the protective status of seagrass habitats. It is recommended that monitoring of S. muticum should continue, especially in areas of high amenity value and economic importance in order to observe possible effects on local flora and fauna, aquaculture, the seaweed industry and tourism.


Geographical distribution Ireland Point introduction Rock pools Sargassum muticum Seagrass beds Spreading rate Transport Vector 



The author is very grateful to Anita Gallagher of the Botany Department, NUI, Galway, and Aurore Raveneau of the Agricultural college, ENESAD, Dijon, France, for their assistance with fieldwork; to Astrid Werner, Jim Morrissey and Robert Wilkes for help with the surveys; and particulary to Lin Baldock, Clare Heardman, Marie Mahon Padraig Whelan and Padraig Gannon for additional records of S. muticum. Special thanks to Dan Minchin of Marine Organism Investigations and Julia Nunn of the Ulster Museum and Botanic Gardens, Belfast, for records of 2005 and 2006. This project was partially funded by the Heritage Council under the Wildlife Grant Scheme 2003 and received support from NUI Galway’s Millennium Fund.


  1. Arenas F, Fernadéz C, Rico JM, Fernandéz E, Haya D (1995) Growth and reproductive strategies of Sargassum muticum (Yendo) Fensholt and Cystoseira nodicaulis (Whit.). Roberts Sci Mar 59(1):1–8Google Scholar
  2. Arenas F, Sanchez I, Fernandez C, Hawkins SJ (2003) The impact of invasive species on European shores: the case of Sargassum muticum in intertidal rock pools. In: Maggs C (ed) Programme and book of abstracts. Third European Phycological Congress. Taylor & Francis Group, Belfast, Northern Ireland, p 49Google Scholar
  3. Boaden PJS (1995) The invasive seaweed Sargassum muticum (Yendo) Fensholt in Strangford Lough, Northern Ireland. Ir Nat J 25:111–113Google Scholar
  4. Britton-Simmons KH (2004) Direct and indirect effects of the introduced alga Sargassum muticum on benthic, subtidal communities of Washington State, USA. Mar Ecol Prog Ser 277:61–78CrossRefGoogle Scholar
  5. Christensen T (1984) Sargassotang, en ny algeslægt i Danmark. Urt 4:99–104Google Scholar
  6. Critchley A (1981) Age determination of Sargassum muticum (Yendo) Fensholt. Br Phycol J 16:134Google Scholar
  7. Critchley AT, Farnham WF, Morell SL (1983) A chronology of new European sites of attachment for the invasive brown alga Sargassum muticum 1973–1981. J Mar Biol Assoc UK 63:799–811CrossRefGoogle Scholar
  8. Critchley AT, Farnham WF, Morrell SL (1986) An account of the attempted control of an introduced marine algaSargassum muticum, in southern England. Biol Cons 35:313–332CrossRefGoogle Scholar
  9. Critchley AT, Farnham WF, Yoshida T, Norton TA (1990) A bibliography of the invasive alga Sargassum muticum (Yendo) Fensholt (Fucales; Sargassaceae). Bot Mar 33:551–562Google Scholar
  10. Deysher LE, Norton TA (1982) Dispersal and colonisation in Sargassum muticum (Yendo) Fensholt. J Exp Mar Biol Ecol 56:179–195CrossRefGoogle Scholar
  11. Engelen A, Santos R, Alves C (2003) Demography of the alien species Sargassum muticum at its southern European distribution limit. In: Maggs C (ed) Programme and book of abstracts. Third European Phycological Congress. Taylor & Francis Group, Belfast, Northern Ireland, p 48Google Scholar
  12. Fahy D (2001) Harmful seaweed found on Wicklow coast. Irish Times, 20 August. Cited 1 July 2005
  13. Farnham WF (1980) Studies on aliens in the marine flora of southern England. In: Price JH, Irvine DEG, Farnham WF (eds) The shore environment, vol. 2. Ecosystems. Academic, London, pp 875–914Google Scholar
  14. Farnham WF, Jones EBG (1974) The eradication of the seaweed Sargassum muticum from Britain. Biol Cons 6:57–58CrossRefGoogle Scholar
  15. Farnham WF, Fletcher RL, Irvine LM (1973) Attached Sargassum found in Britain. Nature 243:231–232CrossRefGoogle Scholar
  16. Farnham WF, Murfin C, Critchley A, Morrell S (1981) Distribution and control of the brown alga Sargassum muticum. In: Levring T (ed) Proceedings of the Xth International Seaweed Symposium. Goteborg, Sweden. Academic Press, Walter de Gruyter, Berlin, 11–15 August 1980, pp 277–282Google Scholar
  17. Givernaud T, Cosson J, Givernaud-Mouradi A (1991) Etude des populations de Sargassum muticum (Yendo) Fensholt sur les côtes de Basse-Normandie (France). In: Elliott M, Ducrotoy JP (eds) Estuaries and coasts: spatial and temporal intercomparisons. ECSA 19th symposium. Olsen & Olsen, Fredesburg, Denmark, Caen, September 1989, pp 129–132Google Scholar
  18. Hales JM, Fletcher RL (1989) Studies on the recently introduced brown alga Sargassum muticum (Yendo) Fensholt. IV. Effect of temperature, irradiance and salinity on germling growth. Bot Mar 32:167–176CrossRefGoogle Scholar
  19. Hiscock K, Moore J (1986) Surveys of harbours, rias and estuaries in southern Britain: Plymouth area including the Yealm. CSD report no. 752. Natural EnglandGoogle Scholar
  20. Jensen JB (1974) Morphological studies in Cystoseiraceae and Sargassaceae (Phaeophyceae) with special reference to apical organization. University of California Publications in Botany, vol. 68. University of California, p 61Google Scholar
  21. Kornmann P, Sahling PH (1994) Marine algae of Helgoland: second supplement. Helgol Meeresunters 48(4):365–406CrossRefGoogle Scholar
  22. Loughnane C, Stengel DB (2002) Attached Sargassum muticum (Yendo) Fensholt found on the west coast of Ireland. Ir Nat J 27(2):70–72Google Scholar
  23. Marine Institute (2006) Weather buoy data. Cited 5 June 2007
  24. Norton TA (1976) Why is Sargassum muticum so invasive? Br Phycol J 11:199CrossRefGoogle Scholar
  25. Raines P, Nunny R, Cleator B (1992) Isles of Scilly expedition 1992. Coral Cay Conservation Sub-Aqua ClubGoogle Scholar
  26. Ribera MA, Boudouresque CF (1995) Introduced marine plants, with special reference to macroalgae: mechanisms and impact. Progr Phycol Res 11:187–268Google Scholar
  27. Rueness J (1989) Sargassum muticum and other introduced Japanese macroalgae: biological pollution of European coasts. Mar Poll Bull 20:173–176CrossRefGoogle Scholar
  28. Schaffelke B, JE Smith, CL Hewitt (2006) Introduced macroalgae – a growing concern. J Appl Phycol 18:529–541CrossRefGoogle Scholar
  29. Simkanin C (2004) The invasive seaweed Sargassum muticum (Yendo) Fensholt in Lough Hyne Marine Nature Reserve, Co. Cork. Ir Nat J 27:481–482Google Scholar
  30. Stæhr PA, Pedersen MF, Thomsen MS, Wernberg T, Krause-Jensen D (2000) Invasion of Sargassum muticum in Limfjorden (Denmark) and its possible impact on the indigenous macroalgal community. Mar Ecol Progr Ser 207:79–88CrossRefGoogle Scholar
  31. Steen H (2004) Effects of reduced salinity on reproduction and germling development in Sargassum muticum (Phaeophyceae, Fucales). Eur J Phycol 39:293–299CrossRefGoogle Scholar
  32. Wernberg T, Thomsen MS, Staehr PA, Pedersen MF (2001) Comparative phenology of Sargassum muticum and Halidrys siliquosa (Phaeophyceae: Fucales) in Limfjorden, Denmark. Bot Mar 44:31–39CrossRefGoogle Scholar
  33. Winder F (2002) Sargassum muticum in Kenmare River, Co. Kerry. Ir Nat J 27:85Google Scholar
  34. Withers RG, Farnham WF, Lewey S, Jephson NA, Haythorn RM, Gray PWG (1975) The epibiota of Sargassum muticum in British waters. Mar Biol 31:79–81CrossRefGoogle Scholar
  35. Wynne G, Avery M, Campbell L, Gubbay S, Hawkswell S, Juniper T, King M, Newberry P, Smart J, Steel C, Stones T, Stubbs A, Taylor J, Tydeman C, Wynde R (1995) Biodiversity challenge, 2nd edn. Royal Society for the protection of Birds, RSPB, Sandy, UKGoogle Scholar
  36. Yendo K (1907) The Fucaceae of Japan. J Coll Sci Tokyo Imperial Univ 21(12):1–174Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2007

Authors and Affiliations

  1. 1.Irish Seaweed Centre, Martin Ryan InstituteNational University of Ireland, GalwayGalwayIreland

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