How the marine ecosystem in Maui is faring 1 year after the wildfires

Scientists say they still don't understand the full extent of the damage the Maui wildfires did to the corals and marine ecosystem off the west coast of the island.

After an initial blaze sparked into a weeklong series of wildfires, the needs of those on land -- resulting from at least 100 people dead or missing as well as entire neighborhoods obliterated -- remained the priority in the months following, leaving little resources left to monitor the marine environment, researchers told ABC News.

"We almost felt like it was even inappropriate at first to talk about the research we were doing, just because there was so much pain on our island," Liz Yannell, program manager at Hui O Ka Wai Ola, a citizen science network based in Maui, told ABC News.

The immediate concern for the coastlines was the debris that was washing into the water offshore, as well as any ash and other toxins that affect air and water quality being carried by the smoke, John Starmer, science director at the Maui Nui Marine Resource Council, told ABC News. In addition, the boats that sank were leaking fuel and other chemicals into the Pacific Ocean.

The murky water appeared so precarious that "nobody wanted to get in" to examine it, Starmer said.

"It was difficult to really get a sense of what the conditions were," he said.

Researchers initially used a remotely operated vehicle and artificial intelligence to map the reefs off the coastline. Once there was less fear about contamination levels in the water, researchers began to conduct dive surveys. They have been testing the water quality for a suite of samples for metals and other general water quality parameters, like nutrients, Andrea Kealoha, assistant professor in the Department of Oceanography at the University of Hawaii at Manoa, told ABC News.

It was clear from the onset of the fire recovery that the cleanup efforts would be long, difficult and arduous and that the wildfires would have lasting environmental impacts on the island.

When the fires struck, environmental advocates feared the first big rain that would come in the wet season -- typically in November, which would have been just three months after the wildfires, Yannell said.

But mother nature was on Maui's side this time, with the "first flush" not occurring until Jan. 10, giving crews much more time to clear piles of debris, she added.

Still, despite the delayed rains, massive plumes of sediment washed over the reefs in the runoff when the first big storm moved through, Starmer said.

"Once it hits the water, you can't really do anything about it," he said.

Researchers say they have found metals in the water -- such as copper, which is often used to prevent barnacles from growing on boats.

Despite the widespread devastation and the gargantuan cleanup mission, there is no evidence that the corals or marine ecosystem as a whole in West Maui were physically damaged as a result of the fire, the researchers said.

Visually, there are no impacts, Kealoha said.

"That doesn't mean that we're out of the woods yet," Starmer said.

The Scripps Institution of Oceanography has established a monitoring site in Launiupoko, just south of Lahaina and adjacent to the dump site where they are putting the wildfire debris, following concern expressed in the local community about contamination from that dump impacting the nearby reefs at Launiupoko and Olowalu, the marine research institution announced last week.

Researchers cautioned against conflating the current lack of evidence with the possibility that the marine ecosystem in West Maui were left unscathed by the wildfires in the longterm.

Continued testing is starting to present evidence that there is chemical pollution and other residual environmental consequences of the fires, Starmer said. The toxins are likely bioaccumulating and moving up the food chain, with some fish testing positive for PCBs and PAHs -- industrial chemicals -- he added.

Complicating monitoring efforts is the fact that wildfires -- especially urban fires than contain man-made chemicals -- rarely occur near reef systems. Therefore, the researchers don't know what to expect. They barely know what they're looking for, they said.

"There's not any substantial research that was easy to find about urban fires next to coastal waters and what that means for a coral reef ecosystem that's already so delicate and already struggling," Yannell said.

Globally, coral reef systems are struggling due to stressors like pollution and increasing ocean temperatures. Overall, the longterm health of the marine ecosystem in West Maui is unclear, and marine researchers will continue their quest to understand how the corals were affected and attempt to prevent runoff contaminated with toxins from rushing into the ocean.

But signs of a recovering marine ecosystem are present. The humpback whales have returned to the region on their annual migration routes, monk seals have taken up residence on their favorite beaches and crabs have reclaimed their favorite spots along the shore, Yannell said.

One of the silver linings of the wildfire aftermath is the reefs have "had a break from people," such as tourists and surfers, similarly to what happened during the isolation measures of the COVID-19 pandemic, Kealoha said.

"While the world above water has completely changed, the reefs look fairly healthy and comparable to pre-fire coral cover data," Orion McCarthy, a marine biologist at the Scripps Institution of Oceanography, said in a statement. "It's still too early to say there is no impact."