Record Heat Thrusts Hawaii Corals Into ‘New Era’ Of Bleaching
The reefs have never had to endure such conditions. Marine scientists remain optimistic but warn that time is running out for society to step up.
Hawaii’s corals are in peril, jeopardizing an important source of security, revenue and food for the state.
The ocean has been too hot for too long this summer for these tiny animals to handle. It’s causing the corals to expel the symbiotic algae that lives inside them, which leaves their bony skeletons fragile and white.
This is the third widespread coral bleaching in Hawaii since 2014. It happened once in the 1980s and once again in the 1990s, scientists said, but it’s on track to become an annual event by 2040 without a dramatic reduction in carbon emissions globally and stronger resource management locally.
“The coral reefs of the future will undoubtedly look different than today,” said Jamison Gove, a research oceanographer with the National Oceanic and Atmospheric Administration. “But just how different will depend on us as a society.”
Government, university scientists and satellite companies have partnered to document the current bleaching event, which includes a way for citizens to report what they see in the water via the Hawaii Coral Bleaching Tracker website.
It’s a partnership led by Greg Asner, who directs Arizona State University’s Center for Global Discovery and Conservation Science. It includes NOAA, the Hawaii Division of Aquatic Resources, Allen Coral Atlas and Planet labs, which are expected to soon make it possible to effectively monitor the world’s reefs by satellite.
This NOAA graphic shows coral bleaching conditions around the Main Hawaiian Islands from late July through September.
Dozens of hot spots have been logged on seven of the eight Main Hawaiian Islands so far, though the data naturally skews toward population centers. Scientists are planning to target the more remote areas to shore up the gaps.
The information has yet to be analyzed but it’s already clear that some places are faring worse than others. Corals off the Kona coast of Hawaii island are in bad shape, as are those around Lanai and south and west Maui, scientists said.
“Our hope is we’ll see the same kind of resilience after this bleaching event.” — Cindy Hunter, University of Hawaii marine biologist
Cindy Hunter, a biologist who directs the Marine Option Program at the University of Hawaii, was shocked when she observed more than 80% of the coral off Lanikai Beach on Oahu was bleached by late August — a month earlier than expected.
But she and other scientists have retained a degree of optimism.
“These are the same colonies that bleached and recovered in 2014 and 2015,” she said. “Our hope is we’ll see the same kind of resilience after this bleaching event.”
Some species have proven more tolerant to the warmer waters. Montipara, known as sandpaper coral, did not bleach five years ago and does not appear bleached this year, Hunter said.
Robert Richmond, a research professor and director of the UH Kewalo Marine Laboratory, has been trying to figure out why some corals are hardier than others and what that means in light of a changing climate.
“I’m personally an optimist, otherwise I can’t get out of bed in the morning,” he said. “But professionally I’m a pragmatist, or I can’t do my job.”
The lab has learned that certain proteins turn on when they are stressed by heat or acidity or local stressors like sedimentation and polluted runoff, he said. That helps scientists understand cause and effect, and in turn what management measures should be recommended to target the problem.
“If we don’t deal with climate change then it will be catastrophic for the future.” — Robert Richmond, Kewalo Marine Laboratory
Richmond finds hope in knowing some species are naturally resilient. He calls them “Phoenix corals,” because they seemingly rise from the dead. Porites lobata, a mounding lobe coral, packs more algae into its skeleton and withstands bleaching better.
But at the same time, there has never been this long a period of continuous bleaching. The corals don’t have as much time to recover in between each event, which increases the risk of mortality.
“Coral reefs are threatened but not doomed,” Richmond said. “There’s a window to act but that window is closing. If we don’t deal with climate change then it will be catastrophic for the future.”
Marine Managers Feel The Pressure
Brian Neilson heads the state Division of Aquatic Resources, the lead agency responsible for managing nearshore waters around Hawaii.
Regulations may need revamped for a “new era” in which coral bleaching is common, he said.
He has mobilized his team to “get eyes on the water” and hit some of the data gaps in reporting the current coral bleaching event.
This NOAA Coral Reef Watch animation shows the threats to coral reefs this summer throughout the Pacific.
But much of the work is just observation. There are no intervention methods that managers can deploy at this point, though there is some research in developing those, he said.
The division has worked to boost public education, giving informational cards out to dive shops and putting out press releases urging residents and tourists to be extra careful to not harm the reefs.
Don’t step on or touch the corals. Don’t drop anchor on reefs. If you’re washing your car or changing your oil or fertilizing your yard, keep that away from the drains that go into the ocean.
“It’s things we should be doing all the time but it’s especially sensitive now,” Neilson said.
A school of yellow tang swims along a reef on the Kona coast of the Big Island. Healthy coral reefs are home to many species of fish, providing food for humans. They’re also natural seawalls that protect coastlines and communities from weather and wave damage.
Alana Eagle/Civil Beat
The state is in its “9th degree heating week,” as scientists call it. That means the water temperature has been above the threshold for coral to start bleaching and it’s been sustained for over two months.
Bleaching has been observed in 5% to 10% of corals around the state, he said, but that’s expected to increase as more reefs are surveyed and temperatures remain warm this month as forecast.
The division is trying to switch its management strategy in light of more bleaching. Neilson anticipates new measures to protect the reef fish that keep the algae at bay after bleaching events. That will likely mean new bag limits for uhu, or parrotfish, and kala, or unicorn fish.
These natural underwater lawnmowers clear away areas on dead reefs so new corals can settle and slowly reestablish.
“We all love the bright colors just because they’re beautiful but there’s also real economic value.” — Brian Neilson, Hawaii Division of Aquatic Resources
Neilson said he and his team will be going into the community early next year to get public input on ways to manage the state’s fisheries better. This ties into Gov. David Ige’s sustainability goal of effectively managing 30% of the state’s nearshore waters by 2030.
“For reef lovers, we all love the bright colors just because they’re beautiful but there’s also real economic value,” Neilson said. “It supports the tourism industry. It puts food on the table. And it’s shoreline protection.”
The U.S. Geological Survey put out a big study this year that found reefs provide $836 million a year in shoreline protection from hurricanes and flooding for Hawaii. They serve as a natural buffer to protect coastal roads, homes and businesses.
If the corals die, the reefs collapse into fields of rubble, said UH climate researcher Chip Fletcher.
“This changes wave energy dissipation, surf breaks, nearshore currents, beach stability and of course loss of biodiversity and ecosystem function,” he said.
‘It Needs To Happen Now’
The world’s leading scientists released a report last week that forecasts worsening conditions for many coral reefs.
The Intergovernmental Panel on Climate Change’s special report on the oceans says marine heatwaves will be 20 times more frequent even if the world’s nations meet the pledges they made to keep global warming well below 2 degrees Celsius above pre-industrial levels by 2100.
Marine heatwaves could be 50 times more frequent if greenhouse gas emissions continue to increase, the report says.
Nations are falling short of the pledges they made in Paris in 2015 to avert the most dire effects of climate change.
The U.S., which is the world’s second largest emitter of carbon dioxide, Russia and Saudi Arabia are among the worst offenders, according to a report last month by National Geographic and Climate Action Tracker. The Gambia, Morocco and India were top of the class, given their goals and progress on shifting toward more renewable energy.
President Donald Trump plans to pull the U.S. out of the accord as soon as possible, which is the day after the November 2020 election. Other world leaders are waffling, such as Brazil President Jair Bolsonaro.
But new commitments have been made at local levels. Hawaii has bound itself to the Paris agreement and half the country is now part of the U.S. Climate Alliance, in which states agree to accelerate policies that reduce carbon pollution and promote clean energy deployment.
Gose, the NOAA oceanographer, said global policies must aggressively reduce burning fossil fuels to avoid creating a world within the next 20 years where coral bleaching occurs every summer.
“Society has the ability to make the changes needed to allow for coral reefs to continue to exist,” he said. “We have that capacity. It needs to happen, and it needs to happen now.”