Hawaiʻi’s Corals Were Struggling To Survive. Then Came The Mud Floods

Coral reefs already face a litany of threats. Experts say storm runoff from the recent Kona lows will only make matters worse.

Last week’s powerful Kona low storms, which caused catastrophic flooding on land, might also have devastated much of Hawaiʻi’s nearshore corals and reef fish, smothering them in tons of mud laced with pesticides and other toxic runoff, marine experts and conservation groups say.

Divers have barely started to survey the damage below the surface, as the lingering murky, polluted waters have kept most areas unsafe to enter throughout the state. Still, a worrisome picture is emerging.

The coastal waters off Waialua, the area hardest hit on Oʻahu by the floods, boast beautiful, abundant coral that stretch to the island’s northwestern tip, at Kaʻena Point, said Alika Garcia, a diver, spear fisherman and executive director of the nonprofit Kuleana Coral Restoration.

Those waters remain chocolate brown, raising concerns coral bleaching or even die-offs could…