Rewilding the Oceans

Ocean ecosystems can recover with remarkable speed once pressures are removed. In marine protected areas where fishing is banned, fish populations often rebound dramatically within a decade.

Mexico's Cabo Pulmo reserve is the standout: a depleted fishery that, after ten years of protection, saw fish biomass climb over 460 percent, with the boom spilling over into surrounding waters.

Off California, restoring a single key species — sea otters that keep urchins in check — has revived whole kelp forests that store carbon and support fisheries.