Estimates of recovered kelp area within 5 regions.

Predicted area (in km2) of kelp (Laminaria hyperborea, Lh) recovery and sea urchin (Strongylocentrotus droebachiensis, Sd) persistence in each of five regions along the Norwegian coast, where region 1 is the southernmost region. Areas with regrowth of other macroalgae were estimated as 100% minus the area with kelp recovery and the area with sea urchin persistence. We used the cut-off probability values equal to the Youden index (YI) for the BRT model for kelp recovery (0.27) and sea urchin persistence (0.31). The numbers in brackets are the size of the area in percentage of the total study area.