Recent changes in the seaweed community of Western Prince Edward Island: implications for the seaweed industry

Before 1980 seaweed beds of western Prince Edward island, Canada, were dominated by Chondrus crispus associated with 37 other species of common algae. Furcellaria lumbricalis occurred in 4.6 per cent of samples in the Pleasant View bed. Diving and ranking surveys were conducted in 1991 to determine the changes in species composition and abundance in seaweed beds. F. lumbricalis was reported in 67 per cent of the samples from the Pleasant View bed. F. lumbricalis biomass was negatively correlated with C. crispus biomass and positively correlated with Phyllophora spp. biomass. Harvesters avoid areas with unacceptable levels of F. lumbricalis. F. lumbricalis in the sampled commercial harvest was 3.1 per cent by weight and the mean content of C. crispus was 97.6 per cent. Management strategies to reduce the abundance of F. lumbricalis are limited by environmental and socio-economic factors.