The huiro negro, the black kelp that carpets Chile's rocky intertidal zone, functions as an underwater forest: habitat, nursery and refuge for a long roster of coastal species. A study led by Alejandra González of the Universidad de Chile's Department of Ecological Sciences, with student Natalia Sanhueza and collaborators at the Universidad Austral and the Universidad Católica del Norte, projects a bleak trajectory for it. Published in PLOS ONE as Kelps on the move, the modelling covers the Pacific coast of South America.
The two species examined, Lessonia berteroana and Lessonia spicata, are endemic to the region. Under the projections, both lose more than 58 per cent of their potential habitat by 2050, with the heaviest contraction in northern and north-central Chile. Strikingly, the model considered rising temperature alone. The authors emphasise that mass harvesting, illegal extraction, coastal development and pollution all press on the same populations, so the projection is, if anything, conservative about the forests' prospects.
The team describes the work as an initial diagnosis within a longer research programme, and it is paired with action. González's group is growing macroalgal chimeras from local genetic material and returning them to the same stretches of coast, working alongside fishing communities and conservation organisations. For a resource that underpins both biodiversity and artisanal livelihoods, the study turns a vague anxiety about warming seas into a mapped, dated and testable warning.