To restore Palmyra Atoll, The Nature Conservancy, U.S. Fish and Wildlife Service, and Island Conservation shift our focus to invasive coconut palms and the restoration of native trees.

Restoring an island from rainforest to reef is a complex endeavor, one that The Nature Conservancy, U.S. Fish and Wildlife Service (USFWS), and Island Conservation started more than a decade ago on Palmyra Atoll, a tiny chain of islands in the middle of the Pacific Ocean. Palmyra has a long history of use and modification as a coconut palm plantation, a U.S. military base during World War II, and more. Today the island is a national wildlife refuge and is co-managed by The Nature Conservancy and the USFWS. Palmyra is not inhabited by permanent human residents other than researchers and staff members but hosts a variety of native flora and fauna. From the manta rays cruising the coastline to coconut crabs scurrying along the sand, and red-footed boobies roosting in the branches of native Pisonia trees, the interconnectivity of the ecosystems is undeniable.

Palmyra was not always so pristine, but is well on its way to recovery. In 2011, The Nature Conservancy, U.S. Fish and Wildlife Service, and Island Conservation successfully removed invasive black rats from the atoll to secure nesting habitat for the region’s seabirds. The island saw remarkable recovery over the next several years, including a 5000% increase in native vegetation. Along with the resurgence of native trees, came the proliferation of invasive coconut palms. Without the rodents around, the rapidly growing coconut trees were able to spread in greater numbers, forming dense thickets and outcompeting the islands’ many native tree species. While this relationship was anticipated, it occurred much more quickly than researchers expected.

You can’t isolate the effects of one thing from the trickle-out effect it can have on everything else,” says Ana Miller-ter Kuile, a doctoral candidate at the University of California, Santa Barbara, and lead author of the paper.

Removing the rats was the start of replenishing the native life of the atoll, however, researchers are now shifting focus to the coconut palms to help sustain and grow colonies of seabirds that rely on native trees. Seabirds on Palmyra Atoll provide vast ecosystem services, in particular, the transfer of nutrients from sea to land and back again through their guano. Roosting in the native trees, seabirds’ nutrient-rich guano seeps into the surrounding marine environment,  feeding phytoplankton blooms, which support larger fish and supply nutrients to corals. By removing invasive coconut palms from much of the atoll and planting native trees, the partners hope to give native seabird populations a boost and further explore the relationship between terrestrial and marine restoration. Alex Wegmann, director of science for The Nature Conservancy of Hawaii’s Palmyra Program hopes to see fully established canopies of native trees within 15 years, based on the successes of trees planted around 2005. These canopies will include trees such as the Pisonia grandis and Heliotropium foertherianum, which are favored by Great Frigatebirds and Red-footed Boobies. 

Beyond the rainforest and reefs of Palmyra, this restoration will stand to benefit similar islands and ecosystems around the world through the insight and research conducted. Tetiaroa Atoll in French Polynesia, a near-pristine tropical atoll ecosystem, is one of the many that stand to benefit from the restoration of Palmyra. In July 2021, Tetiaroa Society and Island Conservation will continue a project to remove invasive rats from the 12 islands in the atoll—a critical first step in boosting the native seabird population. The lessons we learn on Palmyra have and will inform island restoration on a global scale, giving greater insight into the deep connections between terrestrial and marine ecosystem restoration. The potential for reversing the damage inflicted by humans on wild and special places including the Palmyra Atoll is immense and will allow island conservation practitioners to expand the scope of this work and continue preventing extinctions of island wildlife. 

Source: Atlas Obscura
Featured photo: Aerial view of Palmyra Atoll. Credit: Kydd Pollock/The Nature Conservancy