The Ascophyllum nodosum industry in the Maritimes stemmed from its long-standing use as fertilizer in Europe. Nova Scotia’s A. nodosum commercialization began with the 1959 Sea Plants Harvesting Act, granting exclusive harvesting rights along coastal areas. Over 62 years, the industry evolved through five distinct periods, including changes in ownership, harvest technology, and products. The main driver was the allocation of the resource via leases, resulting in mechanization during Periods II and III, followed by demechanization in 1995, Period IV. A shortage of manual labor has necessitated the reintroduction of mechanical harvesting in Period V. Exclusive leases promoted expansion of the industry to New Brunswick and the southern and eastern shores of Nova Scotia in Periods IV and V. Control of the resource up to 15 years allowed the development of area-based annual management plans at hectare resolution enabling sustainable harvests. In Period IV, there was a significant shift in the allocation of leases in Southwestern Nova Scotia, leading to a loss in alginate production and a 67% decrease in landings. In Period V, landings recovered due to investments in biostimulant products for agriculture and continued production of traditional kelp meal products.