When diving in Hawaiian Islands Humpback Whale National Marine Sanctuary with XL Catlin Seaview Survey, NOAA diver Mitchell Tartt took this photo of a crown-of-thorns starfish nestled into the reef. While they do feed on coral, as seen here, crown-of-thorns starfish are important members of the reef community and part of the rich biodiversity that makes the Hawaiian Islands such a beautiful place. Of course, when the balance shifts and an outbreak of these animals ensues -- as has recently happened in National Marine Sanctuary of American Samoa -- their consumption of corals can have negative impacts on reef health, so we closely study the health of reef ecosystems across the sanctuary system.