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Threats to the Marine Environment


Dead Porites coral with bore-holes, Kewalo


Sea Urchin bore-holes, Makapu'u, Oahu

Midway Lagoon with Pencil Urchins


Parrotfish bite marks, Honaunau, Hawaii

Parrotfish bite marks, Honaunau, Hawaii


Sea Urchin erosion, Honaunau, Hawaii

Natural breakdown of reefs takes place continuously.  Parrotfishes bite off chunks of coralline material while some large filefishes remove the tips of Cauliflower coral.  Boring sea urchins, sponges, and mollusks erode reefs from the inside-out.  This process is easily observed in Midway Lagoon where the ancient reef limestone is riddled with urchin holes, causing sections to break apart during high surf.