Coral reefs are Hawaii’s ‘rainforests of the sea.’ What happened to them after Lahaina wildfire?

Abraham “Snake” Ah Hee rides waves when the surf’s up and dives for octopus and shells when the water is calm. The lifelong Lahaina, Hawaii, resident spends so much time in the ocean that his wife jokes he needs to wet his gills.

But these days Ah Hee is worried the water fronting his Maui hometown may not be safe after the deadliest U.S. wildfire in a century scorched more than 2,000 buildings in August and left behind piles of toxic debris. He is concerned runoff could carry contaminants into the ocean where they could get into the coral, seaweed and food chain.

“Now with all these things happening, you don’t know if the fish is good to eat,” Ah Hee said.

Scientists say there has never been another instance of a large urban fire burning next to a coral reef anywhere in the world, and they are using the Maui wildfire as a chance to study how chemicals and metals from burned plastics, lead paint and lithium ion batteries might affect delicate reef ecosystems.

The research, which is underway in the waters off Maui, could help inform residents, tourists and coastal tropical communities worldwide as climate change increases the likelihood of extreme weather events of the kind that fueled the wildfire.

A bill before the Hawaii state House would provide long-term funding for water quality monitoring in hopes of providing answers for residents whose lives are closely tied to the ocean.

For now, state officials are urging the public to limit their exposure to the ocean and seafood until scientists understand what might be making its way through the food chain.

“I know a lot of people keep asking, ‘Is the water safe? Can we go out? Is it safe to fish and eat the fish?’” said Russell Sparks, Maui aquatic biologist at the state Department of Land and Natural Resources. “We just want to reinforce the message that we know it’s frustrating, but if people can be patient: We’ve never encountered anything like this.”

Coral reefs are sometimes called the “rainforests of the sea” because they are so crucial to healthy oceans. They are made up of stony corals, which are hard skeletons formed by thousands of individual living coral polyps that symbiotically host algae. Fish, crabs and other species find refuge in their midst. Scientists say one-fourth of the ocean’s fish depend on healthy coral reefs, which also protect shoreline communities from powerful waves during storms.

One of Hawaii’s oldest stories, the centuries-old chant called the Kumulipo, reflects the central role of coral in the island chain. It says a coral polyp was the first living being to emerge from the darkness of creation. Starfish, worms, sea cucumber and other species followed. Humans came last.

“So the first form of life is a coral polyp. That is your foundation. The foundation of life is a coral,” said Ekolu Lindsey, a Lahaina community advocate who has long pushed to restore coral reefs, fishing and traditions in his hometown.

Lahaina’s coral reefs had challenges even before the fire, including overfishing, abuse from kayak and stand-up paddleboard tours, warming ocean temperatures and sediment flows from fallow fields and construction sites, Lindsey said.

Much of the coral offshore from the burn zone was already degraded before August, Sparks said, but there were some patches of nice reef, like in an area north of Lahaina Harbor toward Mala Wharf.

Sea Maui, a whale watching and snorkeling tour company, frequently took snorkelers to the Mala Wharf reef, where they would often see turtles and sometimes monk seals. Now, the company’s boats avoid the reef due to concerns about runoff and out of respect for the town, said Phil LeBlanc, partner and chief operating officer.

“We’re not into disaster tourism,” said LeBlanc, who instead sends tours south to Olowalu or north to Honolua Bay.

University of Hawaii at Manoa researchers obtained a $200,000 grant from the National Science Foundation to test the water soon after the fire.

In October, they placed 20 sensors off West Maui that measure temperature, salinity, oxygen, turbidity and chlorophyll every five minutes. They have six sensors measuring where water is flowing for clues on where contaminants might travel and accumulate, said Andrea Kealoha, a UH Manoa professor and Maui native who is leading the research project.

The Hui O Ka Wai Ola citizen science group collects additional samples, including after heavy rain events.

Researchers are taking tissue fragments from fish, seaweed and coral for signs of heavy metals and contaminants from burned wood, metal and plastics.

Their grant covers work through August. So far they don’t have enough data to draw conclusions but aim to release some results within a month.

Kealoha suspects scientists may detect contaminants accumulating in plants and animals over the next two to five years. Degraded reefs and lower water quality could emerge over the same time frame, and she is pressing for a long-term monitoring plan that could be supported with state funds, she said.

The wildfire’s effects may also stretch beyond Maui, because scientists believe currents carry water from Lahaina waters to nearby Lanai and Molokai.

“Fish that you collect to eat off of a reef on Molokai may very well have compounds that washed into the water from rainfall in Lahaina and got transported to ocean currents across the channel and onto the reefs of neighboring islands,” said Eric Conklin, the Nature Conservancy’s director of marine science for Hawaii and Palmyra.

Authorities have been trying to limit harmful runoff. The U.S. Army of Corps of Engineers is removing rubble and ash. The U.S. Environmental Protection Agency applied a soil stabilizer to prevent ash and dust from dispersing. Maui County officials placed protective barriers alongside storm drains and coastal roads to block debris.

Lindsey, the community advocate, lost his house in the blaze. Immediately after the fire, he was more focused on where he would live and the well-being of his family than the reef. But he also observed that the environment shapes his spiritual, mental and physical health.

He recalled how seeing turtles, seals and hundreds of crab marks on the beach fronting the remnants of his house prompted him to go surfing two months after the fire. January’s heavy rains, and unknowns about runoff, have kept him out of the water since. But he still believes in nature’s capacity to heal.

“When you see resources return like I did, it just fills your heart,” Lindsey said. “Wow, we really messed this place up, and would we leave it alone, nature will fix itself.”