Destruction in Pristine Habitats

Papahānaumokuākea Marine National Monument protects lush coral reefs in the Northwestern Hawaiian Islands. But when researchers surveyed the reefs in summer 2019, they were faced with tragedy: Hurricane Walaka had flattened a reef at French Frigate Shoals, while a newly named species of algae with invasive characteristics was overgrowing native corals and other algae at Pearl and Hermes Atoll. Monument staff are now working to understand and respond to these impacts.

Before

 bright colorful fish swim around corals with a diver in the background
Photo: James Watt/NOAA

After

a baren seafloor
Photo: Kailey Pascoe/NOAA

The before and after photos above show the impacts of Hurricane Walaka, which passed through the Northwestern Hawaiian Islands at French Frigate Shoals as a Category 3 hurricane. The hurricane caused major damage to the islands of this atoll and left rubble at Rapture Reef.

Before

colorful fish swim around corals
Photo: James Watt/NOAA

After

A diver swims above matts of algae
Photo: Taylor Williams/NOAA

Above, before and after images show the impacts of outbreak-level overgrowths of a newly named red alga, Chondria tumulosa, witnessed at Pearl and Hermes Atoll. Many of these mats were as large as multiple football fields. Underneath the mats were dead native corals.