Abstract

Macrocystis pyrifera forms extensive marine forests across the channel-fjord seascape at the southern tip of South America. In October 2022, Chile's fisheries authority banned its extraction in the Magallanes region, renewing the measure in 2024 for 10 years. This initiative was promoted by a fishing sector that does not harvest kelp but relies on the habitat it provides. Decades of research on these forests exist, yet it is dispersed across disciplines and weakly connected to the arenas where fisheries decisions are made; systematizing it is the missing step. We therefore review research on M. pyrifera across the sub-Antarctic ecoregion to assess the evidence supporting this conservation measure. The literature spans eight of the eighteen Nature's Contributions to People categories, but none of the three non-material ones. It documents 535 taxa associated with these forests. Research effort concentrates on two accessible hubs and thins in areas where protection decisions are currently being made. Analyzed through Social-ecological Action Situations and reciprocal contributions, the moratorium highlights a contribution not previously recognized by these frameworks - advocacy for habitat protection - and one it inadvertently restricted: the collection of kelp wrack by smallholder farmers. While kelp governance elsewhere is primarily restorative and implemented after ecosystem decline, in this case, it was preventive. Sustaining this approach will require acknowledging the full spectrum of relationships supported by these forests and advancing protection from decree to law.