Seas of significance: a biosemiotic exploration of seaweed in New Bedford’s coastal cultural heritage

New Bedford, Massachusetts, celebrated for its whaling past and immortalized in Herman Melville’s Moby-Dick , occupies a central place in the American maritime imagination. Yet amid this storied legacy, one coastal presence has remained largely unacknowledged: seaweed. Often considered biologically mundane or visually peripheral, seaweed has been overlooked in cultural narratives despite its enduring material, sensory, and symbolic roles in coastal communities. This paper reframes seaweed as a heritage species and a more-than-human participant in shaping New Bedford’s identity, memory, and environmental rhythm. Drawing on biosemiotics, narrative ecology, and cultural heritage theory, it explores how seaweed functions simultaneously as sign and species. Working with a curated collection of 100 archival items, including pressed seaweed albums, whaling logbooks, oral histories, and maritime ephemera, the article traces how algae have acted as co-creators of cultural practice from the 19th century to the present. A biosemiotic lens positions seaweed within a relational framework of ecological responsiveness and cultural memory. From practical uses in agriculture and maritime labor to its presence in Victorian art, eco-design, and culinary revival, seaweed emerges as a material of continuity and care. Its tactile qualities, symbolic renderings, and seasonal rhythms invite ways of knowing grounded in interrelation. Seaweed’s cultural invisibility stems not from insignificance but from the anthropocentric lens that has shaped heritage frameworks. This study offers a relational model, grounded in biosemiotic feedback and multispecies ethics, that recognizes algae as co-authors of cultural meaning and contributes to emerging conversations in more-than-human geography and environmental humanities. It contributes to ongoing conversations in environmental ethics, public history, and sensory heritage by encouraging new approaches to storytelling, conservation, and governance that foreground the interdependence of human and ecological memory.