The massive fire that engulfed Lahaina, on the Hawaiian island of Maui, killed more than a hundred people, and burned down more than 2200 buildings. And it had a much wider impact as well—on the offshore coral reef.

The fire roared to life on the morning of August 8th, 2023. Fueled by drought, low humidity, and strong winds, it destroyed much of Lahaina, displacing more than 10,000 people.

Ash from the fire drifted offshore and settled atop the reef. Firefighting chemicals and debris from the fire washed into the ocean as well. The contamination threatened the reef and the many creatures that live there. And any damage to the reef could heighten the human misery, because people depend on the reef for food and tourism dollars.

Within days, researchers from the University of Hawaii began studying the reef system. They sampled the water, and set out water-quality sensors at key locations. They also worked with locals to catch fish from the best fishing spots. All of the samples were then analyzed for traces of contamination.

Early analysis revealed high levels of copper—possibly from coatings on the hulls of boats that burned in the fire. It also showed high levels of lead. The levels of both elements have since gone down to safe levels. Zinc went up as well, and climbed even higher after heavy rains washed more contaminants into the water.

Scientists continue to monitor the reef—seeing how it recovers from a human and environmental tragedy.