The Loss of East Island:
By: Ashley Adriano
10 December 2018
Overnight, an entire Hawaiian island was wiped out due to environmental collapse. The beaches were home to many endangered species, plants and animals, but the island now has been reduced to a relatively small pile of sand. Environmentalists have been warning of such imminent and unexpected consequences related to sea-level rise and other ecological degradation. So is East Island an example we can learn from?
East Island was destroyed in October after Hurricane Walaka blasted through the Northwestern Hawaiian Islands. The category 4 hurricane, which had wind speeds of up to 130 to 150 mph, was one of the strongest ever to tear through the Pacific Ocean.
The island was home to the Hawaiian monk seal and the Hawaiian green sea turtle, which used the beaches for nesting and pupping each summer season. The loss of the island means that the two endangered species will now have to start searching for a new place to do so.
Littnan oversees the two programs that research and work to save the endangered Hawaiian monk seal and threatened Hawaiian green sea turtles.
Efforts by NOAA’s Hawaiian Monk Seal Research Program have made it arguably the most proactive marine mammal conservation program on the planet.
Conservation activities starting from the early 1980s and continuing today have had significant results for the monk seals, Littnan said. Over 30 percent of today’s current monk seal population can be traced back to a lifesaving intervention by the program and their partners.
For the monk seals, the loss of East Island is a significant but not catastrophic event. The monk seals that use East Island to pup or rest will likely seek out other islets at French Frigate Shoals to use. Only 10 to 15 pups are born on East Island every year, and less than one-third of all pups are born at French Frigate Shoals. The impact of Walaka was also mitigated by its late summer arrival, as few pups were still nursing on the beach and thus vulnerable to storm surge.
“There’s roughly 170 or so monk seals that live at French Frigate Shoals, and for green sea turtles, French Frigate Shoals is really critical,” said Charles Littnan, head of the Protected Species Division at the National Oceanic and Atmospheric Administration’s Pacific Island Fisheries Center.
The French Frigate Shoals is part of the Papahanaumokuakea Marine National Monument, which is also managed by the United States Fish and Wildlife Service, the Office of Hawaiian Affairs and other state agencies, in addition to NOAA.
Each department has a different set of guidelines to follow, but their goal is the same: to manage the area and help it thrive.
The area includes the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve, the Midway Atoll National Wildlife Refuge, the Hawaiian Islands National Wildlife Refuge, the Battle of Midway National Memorial, Kure Atoll Wildlife Sanctuary and the Hawaii State NWHI Marine Refuge.
According to the Intergovernmental Panel on Climate Change’s October report, research shows that global warming is “likely to reach 1.5 degrees celsius between 2030 and 2052 if it continues to increase at the current rate.”
“Right now, we probably can’t afford to lose too much habitat at French Frigate Shoals or the Northwestern Hawaiian Islands,” said Littnan. “All of those islands are incredibly fragile, low-lying and home to a lot of unique species to the Northwestern Hawaiian Islands.”
While monk seals may be more resilient when it comes to finding a new island to raise their young, the loss of East Island was especially devastating to the green sea turtles because 50 percent of their population used the island as a nesting ground.
Littnan said the loss of the island could possibly even help the population. A small group of Galapagos sharks has specialized in hunting recently-weaned and nursing pups at East Island, a behavior unique to sites in the French Frigate Shoals and the leading cause of mortality to this struggling population of seals.
“What’s going to be really interesting is, we are worried about habitat loss for these animals,” said Littnan. “But it’s also removed breeding habitats that were making these pups vulnerable to shark predation.”
Littnan hopes this predatory behavior will disappear.
The green sea turtles may struggle adapting to relocating to another island. They will have to find sand that they can dig in, is protected from inundation and where their nests won’t be accidentally dug up by other turtles.
Temperature change has already had effects on the green sea turtle population, as sex is determined by temperature. Eggs in cooler temperatures form male turtles, and those in warmer temperatures will be female.
“If these temperatures continue to rise, you’ll get more and more females,” said Littnan. “That’s good up to a point. But eventually, it gets too hot, so that you have failures of the entire clutch, or you don’t have enough males to mate with the females, and you see a population crash.”
Littnan says scientists could see potentially a few radical changes for these animals to respond to in the next few decades.
The closest islands are a few miles away and there are a total of five or six islets in the French Frigate Shoals. There is hope for these species, but uncertainty remains.
Littnan says more questions will be answered once they send a team out to investigate the remains of the island and how the animals have responded.
Seals on East Island. Photos Courtesy of Marylou Staman, M.S. and Brenda Becker of NOAA Fisheries.
Turtles on East Island. Photos Courtesy of Marylou Staman, M.S. and Brenda Becker of NOAA Fisheries.
Former President George W. Bush declared it a national monument in 2006. The monument designation allows for coordinated, multi-agency management of the area. The area became the largest contiguous and fully-protected conservation area under U.S. control after President Obama signed a proclamation in 2016 to extend the area by an additional 582,578 square miles.
The strength of Walaka could be a sign of what could come as a result of climate change, meaning the endangered animals and species in the area are also under threat.
Map (Click on image for link)