Gorilla Ogo

Gorilla Ogo (Gracilaria salicornia)

Photo courtesy of DAR


  • Small, solid, brittle, cylindrical to compressed, irregular branches with segmentation on each branch (Preskitt, 2001; EOR, 2015)
  • Varies in color, from a bright yellow at the tips to orange, green, or brown at the base (EOR, 2015)
  • Has been found to reproduce sexually and asexually (Preskitt, 2001)


  • Grows in close proximity with neighboring benthic organisms to create thick mats and clumps that can be up to 30 centimeters (cm) or more across, and up to 40 cm thick (Preskitt, 2001; CABI, 2019)
  • Typically found in tidepools and on reef flats, up to four meters underwater (Preskitt, 2001)

Impacts & Concern:

  • Widespread dispersal mainly through fragmentation (CABI, 2019; Preskitt, 2001)
  • Fragments are heavy and tend to sink rapidly but remain viable after more than 6 hours desiccation (Smith et al., 2004)
  • Outcompetes native algae and coral and can overgrow areas, shading it from sunlight (CABI, 2019)
  • Can cause ecosystem changes by shifting Hawaiian reefs from coral dominated to algae dominated, leading to low biodiversity (CABI, 2019)
  • Loss of the ecosystem services and structure provided by live coral (CABI, 2019)


  • First identified in 1971on Hawai’i Island in Hilo Bay, where it was likely unintentionally introduced by shipping vessels originating from the Philippines (Preskitt, 2001 & CABI, 2019)
  • In April 1971, G. salicornia was transported intentionally from Hilo to Waikiki
  • In September 1978 it was transferred to Kāne‘ohe Bay on O‘ahu for aquaculture projects that were later abandoned (Preskitt, 2001)

Distribution in Hawaii:

  • Kauai: Unknown
  • O‘ahu: Waikīkī, Pearl Harbor, Maunalua Bay, and Kāne‘ohe Bay (Smith et al., 2004)
  • Molokai: Present, Specific Areas Unknown (Preskitt, 2001)
  • Lanai: Unknown
  • Maui: Unknown
  • Big Island: First discovered in Hilo Harbor, now spread south along the coast (EOR, 2015)

Related AIS Team Management Projects:


  • Smith, J., Hunter, C., & Conklin, E. (2004). Ecology of the Invasive Red Alga Gracilaria salicornia (Rhodophyta) on O‘ahu, Hawai‘i. Hunter Lab. Retrieved March 22, 2021, from http://www.hunterlabhawaii.com/docs/pubs/Gsal%20Smith%20PacSci%202004.pdf
  • Preskitt, L. (2001). Gracilaria salicornia. University of Hawaii Manoa Botany. Retrieved March 22, 2021, from http://www.hawaii.edu/reefalgae/invasive_algae/rhodo/gracilaria_salicornia.htm
  • CABI. (2019). Gracilaria Salicornia. In: Invasive Species Compendium. Wallingford, UK: CAB International.Retrieved March 22, 2021, from https://www.cabi.org/isc/datasheet/107771
  • Eyes of the Reef (EOR). (2015). Gorilla Ogo (Gracilaria Salicornia). Retrieved March 22, 2021, from https://eorhawaii.org/education/marine-invasive-species/gorilla-ogo/