The Orange Keyhole Sponge, Mycale armata Thiele, was unknown in Hawaii prior to 1996. First reported in Pearl Harbor, it now occurs in virtually every commercial harbor in the main Hawaiian islands, where it can be a major component of the fouling community on harbor piers and jetties. It has been reported from a few coral reef locations near harbors, but in Kaneohe Bay it has become a major component of the benthic biota in the south bay in the last 5-10 years. A study was conducted in 2004-2005 to determine Mycale armata's distribution, abundance throughout the bay, its growth rates on permanent quadrats, and whether mechanical removal would be an effective management technique for its control. Results from 190 manta board surveys on 28 reefs and paired 25 m belt transects using photo quadrats on 19 reefs indicated that the sponge had maximal coverage in the south-central part of the bay, in the vicinity of Coconut Island.