The Nova Scotia Research Foundation is making an extensive survey of seaweeds of the Province that are of potential commercial importance. The area in which the survey has been completed extends from Cape Sable Island, Shelburne County to Chebogue, Yarmouth County, and includes also a small part of Digby County. The survey includes both quantitative measurements and biological studies of fucoids,Laminariaspp., andChondrus, in all of which the region abounds. Of 325 miles of coastline surveyed for rockweed, 140 miles are harvestable, bearing approximately 200,000 tons. Results obtained at 255 stations, examined in detail, showed the average density to be 37 lb. per sq. yd. The width of the zone is from 2 to 300 yd., the average being 50 yd.Ascophyllum nodosumforms the greatest percentage of rockweed,Fucus vesiculosusranking next.Fucus serratusis recorded for the first time in this part of the Province.Laminariabeds totalling 12,000 ac. in extent and bearing 900,000 tons were charted. Mortality amongLaminariasporophytes is high and the number in a bed varies from year to year. In 1950 7,997,739 lb. ofChondruswere harvested. Density varies from 1 to lb. per sq. ft.Chondrusbeds are listed and their ecology discussed. Recolonization of denuded areas is described and succession of algal cover noted on denuded areas and on concrete blocks placed inChondrusandLaminariabeds. The survey region is compared with regions surveyed in Scotland. A map of the survey region is included.