The sustainable harvesting of Ascophyllum nodosum (Fucaceae, Phaeophyceae) in Ireland, with notes on the collection and use of some other brown algae

Abstract

Ireland has a long history of seaweed utilisation, with accounts of its use as a food dating to at least the twelfth century. Arramara Teoranta (literally “Seagoods Ltd.”) was established by the Irish Government in the late 1940s to continue the long tradition of sustainable seaweed harvesting in the west of Ireland, which began with kelp ash production from kelp kilns around 1700 and which continued sporadically until 1948. Initially, Arramara purchased dried sea rods (Laminaria hyperborea) and kelp fronds (mostly Saccharina latissima) and these were exported for alginate production in Scotland. Kelps were gradually replaced by Ascophyllum nodosum, a perennial wrack found in the intertidal of the North Atlantic and which is particularly common on sheltered shores in the west of Ireland. This wrack has been cut sustainably by hand in Ireland since at least the late 1940s. Figures for annual production from the main purchaser, Arramara, show that 2,000–7,000 dry weight tons (about 8,000–28,000 wet tons) have been cut in Ireland each year from 1964 to date. Whilst exports for alginate production ceased in 2009, 5,000–6,000 dry weight tons are currently being produced for the animal feed, horticulture, aquaculture, and cosmetics markets.