Gorilla Ogo



  • Small, cylindrical branches with segmentation on each branch
  • Grows intertwining together and with neighboring plants to create a thick mat
  • Varies in color from yellow, orange, to brown
  • Grows on reef flats in shallow waters
  • Very successful in brackish waters like fishponds and intertidal pools


  • High growth rate
  • Spreads by fragmentation
  • Out-competes native alga and coral
  • Grows over coral, shading it from sunlight
  • First documented on Big Island in 1971, then later introduced to Oahu in the 1970s for aquaculture


  • Causes shift in ecosystem; what was once coral dominated is now algae dominated with low diversity
  • Habitat loss greatly affects recreational and commercial fisheries


  • Oahu: Waikiki, Pearl Harbor, Maunalua Bay, and Kaneohe Bay
  • Molokai
  • Big Island: First discovered in Hilo Harbor, now spread south along the coast

Gorilla Ogo distribution in Kaneohe Bay