Improving Reef Resilience in Palmyra Atoll
Posted by Gina Lobaco | , United States
Located 1,600 km south of the Hawaiian Islands, Palmyra Atoll in the Central Pacific is remote, isolated and near pristine. Despite its use as a U.S. Navy facility during World War II, which resulted in significant impacts to its terrestrial environment, Palmyra’s ecosystems have made a remarkable comeback and the atoll became a National Wildlife Refuge, jointly managed by The Nature Conservancy (TNC) and the United States Fish and Wildlife Service (USFWS) in 2001. Palmyra Atoll is the second largest of 10 atolls under US jurisdiction and the only undeveloped and unpopulated "wet" atoll left in the tropical Pacific. The atoll supports spectacular wildlife resources which are the basis of important conservation-based research facilitated by the Palmyra Atoll Research Station.
This collaboration confers a high level of environmental protection for Palmyra as a preserve inside of a National Wildlife Refuge within a Marine National Monument, an area of nearly 53,500 km2. As a result, Palmyra provides scientists a baseline free from human impacts that make it a unique “living laboratory” to study coral reef resilience, ecological interactions, climate change, impacts from invasive species, food webs, and more.
Despite this unprecedented protection, Palmyra faces a serious threat to its reefs. Iron leaching from a shipwrecked fishing vessel is suspected of causing a large area of “black reef,” a phase shift caused by the overgrowth of green algae and a corallimorph (Rhodactis howesii), a cindarian that is known to exploit disturbance events and disrupt reef ecosystems and decrease biodiversity.
At a cost of over $5 million and months-long effort, USFWS removed the shipwrecks in 2014, barging nearly 500,000 kg of debris back to Honolulu. The 300-hectare area immediately surrounding the wreck site is now recovering—thanks to healthy and diverse surrounding reefs. However, the corallimorph spread to Palmyra’s southern and southwestern forereefs. The impressive reproductive capacity of R. howesii may now be enough to support its invasion of Palmyra’s western reef shelf. Removal of the R. howesii is challenging; manual removal is labor intensive and risks the spread of reproductive fragments of the organism; and broad-scale chemical removal puts adjacent marine organisms at risk.
Addressing the Problem
TNC and USFWS, along with the U.S. Geological Survey (USGS) and Scripps Institution of Oceanography researchers are working together to monitor the corallimorph bloom and identify ways to reverse its spread.
With help from the Benioff Ocean Initiative and its brain trust of top marine scientists, we will design and implement a feasibility assessment for maximum control of R. howesii to restore affected reef habitat on the western and southwestern portions of Palmyra’s reef system.
Understanding the nature of this phase shift and developing and executing an action plan to reverse it will provide valuable information for coastal communities elsewhere in the world—like Tanzania, Micronesia, and Fiji—that are seeing similar disturbance-driven phase shifts in their reef systems. Quick, informed conservation action following a disturbance event, e.g., a shipwreck on a remote oceanic island, could greatly increase coral reef resilience in the face of climate-related and other stressors.
TNC is a global conservation leader that uses science to guide its decision-making process. Operating in more than 66 countries around the world, we have the flexibility to develop, test and refine effective techniques for reducing and eliminating threats to native ecosystems. As TNC’s only scientific research station, TNC has supported a research station on Palmyra Atoll that has yielded a rich body of scientific discoveries, encompassing more than 120 peer-reviewed papers in the past 10 years along
We build on decades of expertise and relationships with a wide range of partners to do more, better, faster. Our partnership with USFWS and the Palmyra Atoll Research Consortium provides a model for constructive engagement among equal partners
In the coming year, TNC’s Palmyra Program will be initiating a new collaborative with other remote tropical research stations to leverage research and operational capacity across the Pacific, Indian and Caribbean Oceans.
Call to Action
Despite the significant logistical challenges of working on Palmyra, it is one of the world’s “hope spots,” shedding light on how our oceans and natural world can thrive.
With support for this project, the Benioff Ocean Initiative will add its considerable expertise to maintaining the health of Palmyra’s reefs and demonstrate how our precious ocean resources can be effectively managed.