M.D. Guiry
Department of Botany, University College, Galway, Ireland

and G. Blunden School of Pharmacy, Portsmouth Polytechnic, King Henry I Street, Portsmouth, P01 2DZ, U.K.

Seaweed has been gathered in Ireland for hundreds of years; the earliest printed reference would appear to be in 1726 (1). Until the present century seaweed was collected either as a fertilizer or as a food. Kelp burning was practiced on the west coast during the 19th century, mainly as a source of fer-tilizer; drift seaweed was, and still is, collected in areas where soil is either absent or very poor and mixed with sand to grow crops such as potatoes. Some information on commer-cial utilization of seaweeds in Ireland has appeared in other publications (2-6) but no overall review has been undertaken. In comparatively recent years a number of seaweed dryinq plants have been established but little processing beyond dryinq and milling is carried out in Ireland.

A. Ascophyllum nodosum (Phaeophyta)

This is the most important seaweed collected in Ireland. It is gathered all the year around and is cut by hand from the inter-tidal ensuring that not less than 15 cm. of weed is left for regeneration. In areas not accessible by road the fronds are made into floating rafts and towed to collection Points. Most is now transported wet by road to factories at Kilkieran, Co. Galway, Newport, Co. Mayo and Meenmore Quay Co. Donegal. Here

the plants are dried and exported for alginate production in Scotland. The principal areas where the species is collected are: the Connemara area (Co. Galway) , Co. Mayo, Co. Donegal, the Shannon Estuary (mainly Co. Clare) , with smaller quantities from Co. Cork, Co. Kerry and Co. Sligo. The weed is dried mainly using rotary driers and the product is milled prior to export. Some wet weed is similarly dried at a factory in Kilrush, Co. Clare and exported for use in animal feedstuffs and for the preparation of liquid seaweed extracts for horticultural and agricultural uses. Quantities collected are shown in Table 1.

B. Lamiinaria species (Phaeophyta)

L. digitata is collected mainly as cast weed on Inishiar (Aran Islands) and Quilty, Co. Clare. The plants are mostly air dried in-situ. Most is processed at the Kilrush factory, but the quantity used is very small (Table 1). Good quality weed is used for the production of iodine tablets. Some weed is used to prepare liquid seaweed extracts.

L. hyperborea is collected mainly in April-June as cast weed. The old laminae ('Mayweed') are cast off in spring (2) and large quantities are thrown up during storms. Both stipes and laminae are air dried separately in situ and transported by road; stipes are processed at Kilkieran and the laminae at Kilrush (Table 1). The laminae are oven dried and milled prior to being exported mainly for animal feed with some being used for producing liquid seaweed extracts. Stipes are expor-ted whole for sodium alginate production without further dry-ing; in very recent years stipes have not been used to the same extent as formerly. Collection is mainly on the coast of Co. Clare, particularly in the Kilkee and Ouilty areas.

C. Fucus species (Phaeophyta)

Small amounts (Table 1) of F. vesiculosus are collected in the Shannon Estuary and on the Dingle Peninsula, Co. Kerry all year around. The weed is air dried in situ and is mainly exported for use in the health food industry. F. serratus is also coll-ected all year around in small quantities (Table 1), again mainly in the Shannon Estuary. The weed is air dried and ex-ported; some is used in the manufacture of seaweed extracts.

D. Chondrus crispus (Rhodophyta) - Irish Moss

This is collected by hand picking, mainly in June-September on spring tides. Mostly mature fronds are gathered but many col-lections are of poor quality with up to 30 species of other seaweeds being present. The alga is collected principally on the coasts of Co. Clare (Castlegregory, Quilty, Kilkee and the Burren), Co. Kerry (Fenit, Dingle Peninsula) and Co. Mayo (Clew Bay) with smaller quantities being obtained from Co. Donegal.