Seaweed as the denizens of the new commons in the Anthropocene

The article presents a case for coastal cities to re-envision the current dualistic boundary between city and sea, human and nonhuman, in light of the sea-level rise and storm surges. The aim is to go beyond the traditional defence-driven, mechanical handling of water to engage more meaningfully with the marine world as the water enters our cities. We present seaweed as the representative of the marine world, as a connector between the urban and the marine realm due to its capacity to support life, mitigate climate change, strengthen coastal resilience and impact the local culture and education due to its various ecosystem services. These findings are derived from learnings from three state-of-the-art case studies in Denmark. First, is a design competition incorporating a marine nature-based solution to rethink storm surge protection in Vejle; second is a marine restoration project of a former coastal lagoon in Gyldensteen Strand in Fyn and an artificial underwater reef by the art collective in Copenhagen. The research is based on trans-disciplinary discussions on the value and the role of inviting seaweed as a welcomed key resident of a new coastal commons that fundamentally transform how we live with our watery neighbour, the sea.