Journal of the Marine Biological Association of the UK

Research Article

Long term effects of Ascophyllum nodosum canopy removal on mid shore community structure

S.R.  Jenkins a1c1, T.A.  Norton a2 and S.J.  Hawkins a1
a1 Marine Biological Association, Citadel Hill, Plymouth, PL1 2PB, UK
a2 Port Erin Marine Laboratory (University of Liverpool), Port Erin, Isle of Man, IM9 6JA, UK

Article author query
jenkins sr   [PubMed][Google Scholar] 
norton ta   [PubMed][Google Scholar] 
hawkins sj   [PubMed][Google Scholar] 


The long term effects of macroalgal canopy removal on community composition were investigated over a 12 year period. Experimental removal of the dominant Ascophyllum nodosum canopy led to short term changes in community composition, the major features of which were still apparent 12 years later. Ascophyllum was slow to recover despite high recruitment, and experimental plots were dominated by Fucus species. After 12 years a mixed assemblage of Fucus serratus, Fucus vesiculosus and Ascophyllum had developed. Canopy removal resulted in a change in the balance between grazing limpets and the cover of red algal turf in the understorey community. The cover of turfing algae declined significantly allowing the area grazed by limpets to extend. This led to a 3–6 fold increase in the limpet population 12 years after canopy removal.

(Received August 5 2003)
(Accepted January 13 2004)

c1 e-mail: