Details of this species in Hawaii
Source: HBS, 2002
Arrival Date: 1972
Species Notes for this Location:
It is not known if the invasion by Carijoa riisei is still increasing or if it will spread into shallower water. Clearly it will be important to monitor future patterns of distribution and abundance, as well as to investigate its ecology (growth, recruitment, mortality, reproduction, feeding behavior, predation, and dispersal) (Grigg, 2003).
“Out of 343 introductions of marine invertebrates to Hawaii, C. riisei is the only species to have proliferated to this level of abundance and invasive potential. More research is needed before the island-wide significance of this species introduction in Hawaii can be more fully assessed” (Grigg, 2003).
“Of 287 introduced marine species in Hawaii, only four have become pests, and snowflake coral is the most devastating” (Altonn 2003).
Management Notes for this Location:
C. riisei was not seen on any of the Northwestern Hawaiian Islands from Nihoa to Kure in a comprehensive survey conducted in October 2000 (Coles and Eldredge, 2002).
Economic/Livelihoods: The introduction and successful invasion of Carijoa riisei in Hawaii now threatens the $30 million state-wide precious coral industry with wider ecological implications throughout the Pacific (Grigg 2004). Since 1976, the biomass of black coral in the overall bed off Maui, Hawaii, has decreased by about 25% (Grigg, 2004; Toonen, 2004).
Habitat alteration: ECES (2004) reports that Carijoa riisei is altering habitat by, “Creating structure that act as shelter for fish, which is not so much a negative impact, but this species is also very competitive, feeding on the zooplankton which small fish also eat.”
Reduction in native biodiversity: In the Hawaiian islands, surveys have shown that Carijoa riisei has killed off up to 90% of black coral colonies between depths of 75 and 110m (Grigg, 2003). Altonn, (2003) reports that no big colonies of black coral are left and there are fewer new ones and that without successful management techniques there is the possibility of running out (of black coral) in perhaps 10 years (Altonn 2003).
Last Modified: 23/03/2005 2:21:22 p.m.