At Palmyra Atoll, a remote U.S. wildlife refuge more than 1,000 miles south of Hawaii, conservationists are restoring seabird habitat as one way to support coral reefs facing increasingly severe ocean heat. The effort reflects a connection between land and sea: seabirds feed offshore, then bring nutrients back to the islands in their droppings. Rain washes some of those nutrients into the surrounding ocean, where they help plankton grow. Plankton feed fish and manta rays, and are also eaten by corals. Researchers have found that reefs near seabird colonies are generally healthier. The nutrient cycle is one reason scientists are working to restore the birds’ habitat alongside efforts to protect reefs, which are vulnerable to marine heat waves and bleaching. At Palmyra, that work includes a decade-long project launched in 2019 to replace dense stands of coconut palms with native forest. More than one million palms and sprouts have been removed. The palms are a legacy of plantations established in the 1800s; their crowded forests allow little sunlight in and offer fewer nesting opportunities for seabirds. Invasive rats were another major threat. Their population once reached an estimated 30,000, putting ground-nesting birds at risk. A 2011 eradication campaign led by the U.S. Fish and Wildlife Service and nonprofit partners was followed by a rebound in land crabs, forest growth and seabird nesting, according to Alex Wegmann, The Nature Conservancy’s lead scientist for its island resilience strategy. Some seabirds once believed lost from Palmyra have begun to return. Gray-backed terns have nested there for four consecutive years, and conservationists are using decoy birds to attract other species that no longer appear to breed on the atoll. Palmyra’s reefs were damaged during a 2013 marine heat wave, and not all recovered equally. As heat waves become more frequent and intense, Wegmann says restoring natural ecosystem functions can give reefs a better chance to recover between bleaching events. He cautions that local restoration cannot stop climate change, but says it can reduce other pressures on ecosystems. The approach may have wider relevance: coconut palms have taken over about half the forested land on more than 200 Pacific atolls, and roughly a quarter of the world’s tropical seabirds depend on atolls for nesting. The Nature Conservancy says lessons from Palmyra are also being applied at other island groups, including the Chagos Archipelago in the Indian Ocean.