KAWAIHAE — More than 60 percent of U.S. coral reefs are found in the extended Hawaiian Island chain. The main Hawaiian Islands include more than 4,000 acres of coral reef habitat.
These reefs are a key component of the marine economy and play an incredibly important role in the world’s food chain – providing 500 million people with their primary source of protein.
Knowing this was part of what prompted Big Island scholar Narrissa Spies to spend the better part of the last six years studying corals and coral biology at the University of Hawaii at Manoa.
The other prompter was purely sentimental: Spies was born in Hilo and moved to Kawaihae when she was 10.
“I grew up in a house that didn’t have electricity, so for us going to the beach during the day was an amazing way to escape,” she remembered. “These are our resources in Hawaii, and I feel there’s no one better to care for these resources than the people who grew up here.”
Spies is pursuing a doctorate degree in zoology from UH-Manoa. She was awarded a $45,000 one-year fellowship from The Kohala Center, enabling her to complete and defend her dissertation during the 2017-2018 academic year.
She hopes to defend her thesis and receive her degree later this summer.
In a recent lecture at UH-Hilo, Spies told those gathered, “Over the past 40 years, coral reefs have declined by 50 percent and that’s crazy. Between 1997 and 1998 there was a global bleaching event, an El Nino event, which led to a 70 percent die-off of the coral reef in Florida and the Caribbean.”
“I was shocked that no one really even blinked,” she said.
Spies said the number one threat to coral reefs by far is climate change. Increased carbon dioxide emissions are increasing water temperatures, which in turn is making the ocean highly acidic. Those are global stressors, and there are local stressors as well such as runoff and sedimentation that we can actually do something about, she added.
In a USGS study released last year, scientists estimate that bleaching has affected 56 percent of coral around the Big Island, 44 percent of that along West Maui and 32 percent around Oahu from 2014 to 2015.
“Places like South Kohala were among the hardest hit,” Spies said, “And in areas like Puako and close to Kaunaoa Bay, 90 to 95 percent of the corals did not survive.”
Worldwide, the statistics are just as sobering. The Great Barrier Reef, the world’s largest reef system, was previously thought to have had a one-third die-off but researchers now know one-half is gone.
“That’s huge,” Spies said.
Now, red coral in Japan and some species in Florida are nearly or completely extinct.
In the midst of the doom and gloom, Spies’ research into the molecular biology of coral in Hawaii is offering a glimmer of hope. She has been investigating how certain species of coral are thriving despite stress caused by rising ocean temperatures, pollutants and sediment runoff.
Unexpectedly, her study field is not in the azure waters of the Pacific but instead the polluted Honolulu Harbor.
“It’s a terrible place for any person or fish or anyone else to live, but believe it or not there are corals there that are thriving under this pressure,” Spies said. “And it kind of gives us a little bit of hope.”
As part of her research, she followed the effects on coral and marine life from a massive molasses spill in the harbor in 2013.
“Something as harmless as molasses was an ecological disaster because we could not clean it up,” Spies said. “There was no plan for how to deal with this water-soluble mess other than to wait and let it flush out.”
More than 200 gallons of molasses spilled, killing more than 26,000 fish and countless invertebrates including cucumbers, worms and especially corals. Old colonies of lace coral that were massive and decades-old were completely destroyed when the molasses caused the tissue on the coral to slough off.
There was no chance for that coral to recover, but Spies and her team found two coral colonies that were fine in the molasses water and thriving.
And that, she feels, is a game changer.
“While we didn’t expect to find any kind of life resembling a healthy coral reef ecosystem in this area of Honolulu Harbor, it’s among the most important because this is where selection has already occurred,” Spies said.
“It’s a place where you’re already getting the weaklings weeded and are left with these hardy different genotypes and species that have a better shot of handling the type of stress they’ll experience soon as the effects of climate change worsen.”
For her thesis, Spies focused on two resilient coral species found in the harbor — Leptastrea purpurea and Harbor porites. Harbor porites had previously been incorrectly identified and characterized, so Spies and her team are filing the paperwork to record it as an entirely new species.
Spies was surprised to learn no one had spent time describing these or any of this type of uncommon species before her. She speculates that might be because they’re a bit more difficult to study.
“Their reproductive cycle was previously not known,” she explained. “My dissertation actually characterized both of these species’ reproductive cycles and the different stages of their life history, which is one of the reasons they’re more resilient.
“For example, once you have a coral larvae how does it actually settle and become a new colony? I was able to answer questions about both of these species concerning larval settlement and a method of reproduction which could be a key to their resilience in the harbor.”
Spies conducted controlled laboratory experiments to examine how corals handle their biggest stressor right now: increased water temperature.
“I’m very pleased that the corals I studied are going to do just fine under heat, in addition to all the other chemical stressors found in Honolulu Harbor,” she said. “So it’s really kind of a hopeful story, especially when you see so much death on coral reefs. Resilient places like Honolulu Harbor shouldn’t be overlooked.”
Spies’ research, laying the foundation for understanding resilient coral species, will hopefully provide clues as to why they’re so well adapted to inhospitable habitats such as harbors.
While corals continue to face stress as a result of climate changes, these two coral species serve as excellent models for studying the resilience of corals to stress and may provide insights that can help resources managers in other parts of the world, she said.
“If there are still healthy corals in Hawaii in 50 years, I hope it will be because we’ve been able to build off the work I’ve done through my Ph.D. and applied to other corals on our reefs,” Spies concluded.