Nesting areas on low-lying islands vulnerable to flooding
Shy seabirds that nest mostly on low-lying islands are particularly vulnerable to the threat of sea level rise, USGS researchers said after studying Laysan albatrosses, black-footed albatrosses and Bonin petrels in the Pacific.
“Our study illustrates that sea-level rise threats will affect low-lying Pacific Islands earlier than previously expected,” said seabird ecologist Karen Courtot of the U.S. Geological Survey. “Restoring seabird colonies at higher elevations provides alternatives for species most vulnerable to overwash events before nests are perpetually flooded.”
The birds studied by the researchers have moved away from populated islands and their concentrations are now concentrated on low-elevation islands that are protected as wildlife refuges and marine national monuments. But those protections may not be enough, because those are the same islands threatened most by storm surges and sea level rise.
The scientists modeled sea level rise combined with storm surge at an important seabird breeding colony on Midway Atoll in the subtropical Pacific Ocean.
“A surprising result to many is that some of the most locally abundant species like albatrosses and Bonin petrels were actually the most sensitive to sea level rise impacts,” said Michelle Reynolds, lead author of the USGS-led study.
More than 95 percent of the global breeding populations of Laysan albatrosses, black-footed albatrosses and Bonin petrels are restricted to breeding in the low-lying northwestern Hawaiian Islands. Their egg-laying and chick-rearing occurs when storm waves are most likely to strike.
In the Hawaiian Islands, invasive predators prevent the establishment of seabird breeding colonies at higher elevations and remain a threat to nesting seabirds.
The journal article “Will the Effects of Sea-Level Rise Create Ecological Traps for Pacific Island Seabirds?” was published today in PLOS ONE with lead author Michelle Reynolds and her USGS co-authors Karen Courtot and Curt Storlazzi, and Paul Berkowitz of Hawaii Cooperative Study Unit at the University of Hawaii at Hilo, Janet Moore of Saint Mary’s University, Halifax, and Elizabeth Flint of U.S. Fish and Wildlife Service.