Invasion
Invasion Description
1st Record: a cave off the leeward coast, Oahu/HI/Pacific Ocean (1666, Concepcion et al. 2010)
Geographic Extent
Port Allen, Kauai/HI/Pacific Ocean (2003, Coles et al. 2004); Kaunakakai Harbor, Molokai/HI/Pacific Ocean (2003, Coles et al. 2004); a cave off the leeward coast, Oahu/HI/Pacific Ocean (1666, Concepcion et al. 2010); Oahu/HI/Pearl Harbor (1972, Carlton and Eldredge 2009); Honolulu, Oahu/HI/Honolulu Harbor (1979, Coles et al. 1999); Oahu/Kaneohe Bay (1999, Coles et al. 2002a); Waikiki, Oahu/HI/Pacific Ocean (Coles et al. 2002b); Kahului, Maui/HI/Pacific Ocean (2003, Coles et al. 2004); Maalea, Maui/HI/Pacific Ocean (2003, Coles et al. 2004); black coral bed off Lahaina, Maui/HI/Pacific Ocean (2001, Grigg 2003, at 300 m depth); Hilo, Hawaii/HI/acific Ocean (1997, Coles et al. 2004)
Vectors
Level | Vector |
---|---|
Probable | Hull Fouling |
Regional Impacts
Ecological Impact | Competition | |
Initially, Carijoa riisei was known as an increasingly abundant fouling organism in shallow waters, often on man-made structures in disturbed habitats, with little impact on native corals (Coles and Eldredge 2002). However, a survey of native Black Coral (Antipathes dichotoma and A. grandis) at 30-110 m depth found that many of the corals were being overgrown and killed by the invading Snowflake Coral. In a 2001 survey, 90% of the Black Corals had been overgrown and killed (Grigg 2003; Kahng and Grigg 2005). Exposure to fresh water was tested as an eradication method. Exposure killed polyps in 1.5 minutes, while 15 PSU water took 90 minutes, and 25 PSU water took 2 days. Use of low-salinity water would be limited mostly to man-made structures, possibly by wrapping pilings in plastic (Toonen et al. 2007). | ||
Economic Impact | Fisheries | |
The Black Coral fishery (Antipathes dichotoma and A. grandis) in the Hawaiian Islands was valued at about ~$30 million per year (Grigg et al. 2004). The invasion by Carijoa riisei on beds of Black Coral off Maui, combined with intensified harvesting, has contributed to a ~25% decrease in biomass of the corals (Grigg et al. 2004). These corals are commercially harvested for the manufacture of coral jewelry. Grigg et al. (2004) recommend changes in harvest quotas and size limits to adjust to increased mortality and decreased recruitment of the Black Corals. Limits were imposed on the Hawaiian Black Coral harvest in 2008 (Federal Register 8/13/2008). | ||