Charred Fucus-Type Seaweed in the North Atlantic: A Survey of Finds and Potential Uses

Seaweed forms an important element of diet in many parts of the world and has a wide variety of other uses due to its high mineral content. However, while seaweed remains are relatively frequently reported from archaeological contexts, its use in the past in northern Europe is little understood. Over the past two decades, charred remains of Fucus-type seaweed have been recovered from excavations of sites in Scandinavia and the North Atlantic mostly dated from the Iron Age to the Early Medieval period. At some locations charred seaweed appears to be associated with industry, such as the ironworking sites of Vatnsfjörður and Lækjargata 10–12 in Iceland, and the silversmithing site of Sømme in southwestern Norway. At others charred seaweed finds have been variously interpreted as being related to the preservation of food, agriculture, and textile processing. Furthermore, ethnohistoric evidence documents burnt seaweed being used as fertiliser in arable fields, and seaweed ash is also known to have been historically used in glass manufacture. This paper examines how archaeologists can recover, recognise and interpret charred seaweed remains from archaeological sites, with a particular focus on finds from Iceland.