On a single breath, divers plunged up to 85 feet into the deep.

They were spearfishers, who hunt fish by freediving, armed with a spear or speargun — a continuing Hawaiian tradition that dates back centuries.

In mid-May, the fishers gathered in Hawai'i's Kealakekua Bay, ready to test their mettle. Over the next four hours, they competed in a tournament hosted by ʻIke Lawaiʻa, a local fishing organization, and supported by Conservation International-Hawaiʻi.

The stakes went beyond bragging rights — this was a hunt for invasive fish.

A south swell had turned the water milky and the current strong — not ideal conditions — but the mood among the 24 teams was electric. They methodically dived deep into the bay, hunting for roi, taʻape and toʻau — invasive fish that quietly outcompete native species the bay. By the end of the day, they had pulled 250 pounds of them from the water. That number is lower than last year's haul of nearly 1,000 pounds, but the organizers couldn’t be happier about it.…