|Scientific Name:||Acanthurus blochii|
|Species Authority:||Valenciennes, 1835|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Choat, J.H., Abesamis, R., Clements, K.D., McIlwain, J., Myers, R., Nanola, C., Rocha, L.A., Russell, B. & Stockwell, B.|
|Reviewer(s):||Davidson, L., Edgar, G. & Kulbicki, M.|
Acanthurus blochii is widespread and common in parts of its range. It is a targeted food fish in parts of its distribution (Guam, Saipan and the Philippines) and is harvested for the aquarium trade. There are localized declines observed in the Philippines but there is no evidence of global population declines due to fishing. It occurs in a number of marine protected areas and is therefore listed as Least Concern.
|Range Description:||Acanthurus blochii is found from the coast of East Africa to the Hawaiian Islands and the islands of French Polynesia, northwards to the Ryukyu Islands, Japan, southwards to the Great Barrier Reef and Lord Howe Island, Australia (Randall 2001). It is also reported from Rowley Shoals, Scott Reef and Ashmore Reef (Allen and Russell 1986) and Christmas Island (J.H. Choat pers. comm. 2010). Records from the New South Wales coast may be based on misidentification of A. dussumieri (J.H. Choat and B. Russell pers. comm. 2010).|
Native:American Samoa (American Samoa); Australia; British Indian Ocean Territory; Brunei Darussalam; Christmas Island; Cocos (Keeling) Islands; Comoros; Cook Islands; Disputed Territory (Spratly Is.); Djibouti; Fiji; French Polynesia; French Southern Territories (Mozambique Channel Is.); Guam; Indonesia; Japan; Kenya; Kiribati (Gilbert Is., Kiribati Line Is., Phoenix Is.); Madagascar; Malaysia; Marshall Islands; Mauritius (Mauritius (main island), Rodrigues); Mayotte; Micronesia, Federated States of ; Mozambique; Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Philippines; Réunion; Samoa; Seychelles; Solomon Islands; Somalia; South Africa; Timor-Leste; Tokelau; Tonga; Tuvalu; United States (Hawaiian Is.); United States Minor Outlying Islands (Howland-Baker Is., Johnston I., Midway Is., US Line Is., Wake Is.); Vanuatu; Viet Nam; Wallis and Futuna; Yemen
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – northwest; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
Acanthurus blochii was recorded as occasional in terms of relative abundance in Calamianes Islands, Philippines and the northern Bismarck Sea, Papua New Guinea (Werner and Allen 2000, Allen 2009). It was recorded as common in Milne Bay, Papua New Guinea (Allen 2003). It is moderately common at Raja Ampat (Allen 2003b). It is common in the American Samoa National Park (National Park of Samoa Checklist of Fishes, accessed 21 April 2010). It is one of the most common fishes recorded in the Bar Reef Marine Sanctuary (BRMS), northwestern Sri Lanka. It was found to be most abundant in shallow reef flat and structured sandstone reef habitats (Ohman et al. 1997).
Density and biomass did not change significantly in marine reserves censused in New Caledonia before and after protection (Wantiez et al. 1997).
Density (10-2 fish m-2) 1.26 (0.50) 1.36 (0.39)
Biomass (g m-2) 1.65 (0.33) 2.21 (0.65)
A. blochii accounts for 2% and 1% of the Acanthurid fishery in Guam (Division of Aquatic and Wildlife Resources unpub. data) and Saipan (P. Houk unpub. data) respectively, but shows no signs of decline. It was not observed from the fishery in Ponpei (Rhodes et al. 2008). Average catch is 2,900 kg/year in Hawaii (Division of Aquatic Resources unpub. data). This species is collected as an aquarium fish in West Hawaii. The total number of individuals caught from FY 2005-2009 was 134 with a total value of $182 (Walsh et al. 2010).
In Kenya, landings during 1978-2001 for families that are less important in commercial catches (e.g., scarinae and Acanthuridae) showed rising catches (1978-1984) followed by a general decline during the 1990s, but the landings for the scarinae showed a rising trend in recent years (Kaunda-Arara et al. 2003).
|Habitat and Ecology:||Acanthurus blochii occurs on shallow coral reef (Randall 2001). It is occasionally observed in seagrass beds in Ryukyu Islands (Nakamura amd Tsuchiya 2009). Juveniles settle in coral rubble at Ishigaki Island, Japan (Nakamura et al. 2009). It feeds on detritus and sedimentary material (Choat et al. 2004). It is classified as a grazer/detritivore (J.H. Choat and D.R. Bellwood pers. obs. in Green and Bellwood 2009). Maximum age recorded was 35 years (Choat and Robertson 2002). The sexes are separate among the acanthurids and there is no evidence of sexual dimorphism (Reeson 1983).|
|Use and Trade:||
Acanthurus blochii is one of the most important species captured in islands of the southwest lagoon of New Caledonia (Wantiez et al. 1997). It is also a component of the aquarium trade (juveniles) (GMAD). It sells for $29.99-$99.95 online (L. Rocha pers. comm. 2010).
In the Philippines, it is one of the most targeted Acanthurids. There have been localized declines observed in central Philippines (B. Stockwell pers. comm. 2010).
Acanthurus blochii is a targeted food fish in parts of its range. There have been localized declines due to fishing in the Philippines.
Surgeonfishes show varying degrees of habitat preference and utilization of coral reef habitats, with some species spending the majority of their life stages on coral reef while others primarily utilize seagrass beds, mangroves, algal beds, and /or rocky reefs. The majority of surgeonfishes are exclusively found on coral reef habitat, and of these, approximately 80% are experiencing a greater than 30% loss of coral reef area and degradation of coral reef habitat quality across their distributions. However, more research is needed to understand the long-term effects of coral reef habitat loss and degradation on these species' populations. Widespread coral reef loss and declining habitat conditions are particularly worrying for species that recruit into areas with live coral cover, especially as studies have shown that protection of pristine habitats facilitate the persistence of adult populations in species that have spatially separated adult and juvenile habitats (Comeros-Raynal et al. 2012).
|Conservation Actions:||There are no species-specific conservation measures in place for this species. Its distribution overlaps several marine protected areas in parts of its range.|
Allen, G.R. 2003. Appendix 5. List of the reef fishes of Milne Bay Province, Papua New Guinea. In: Allen, G. R., J. P. Kinch, S. A. McKenna, and P. Seeto (eds), A Rapid Marine Biodiversity Assessment of Milne Bay Province, Papua New Guinea?Survey II (2000), pp. 172. Conservation International, Washington, DC, USA.
Allen, G.R. 2003b. Appendix 1. List of the Reef Fishes of the Raja Ampat Islands. In: Donnelly, R., D. Neville and P.J. Mous (eds), Report on a rapid ecological assessment of the Raja Ampat Islands, Papua, Eastern Indonesia, held October 30 ? November 22, 2002. The Nature Conservancy - Southeast Asia Center for Marine Protected Areas, Sanur, Bali.
Allen, G.R. 2009. Coral Reef Fish Diversity. In: Hamilton, R., A. Green and J. Almany (eds), Rapid Ecological Assessment: Northern Bismarck Sea, Papua New Guinea. Technical Report of survey conducted August 13 to September 7, 2006, The Nature Conservancy.
Allen, G.R. and Russell, B.C. 1986. Fishes (of Rowley Shoals - Scott Reef). Records of the Western Australian Museum Supplement No. 25: 75-103.
Choat, J.H., Robbins, W.D. and Clements, K.D. 2004. The trophic status of herbivorous fishes on coral reefs. Marine Biology 145: 445-454.
Comeros-Raynal, M.T., Choat, J.H., Polidoro, B., Clements, K.D., Abesamis, R., Craig, M.T., Lazuardi, M.E., McIlwain, J., Muljadi, A., Myers, R.F., et al.. 2012. The likelihood of extinction of iconic and dominant components of coral reefs: the parrotfishes and surgeonfishes. PLoS ONE http://dx.plos.org/10.1371/journal.pone.0039825.
Green, A.L. and Bellwood, D.R. 2009. Monitoring functional groups of herbivorous reef fishes as indicators of coral reef resilience ? A practical guide for coral reef managers in the Asia Pacific region. IUCN, Gland, Switzerland.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.2). Available at: http://www.iucnredlist.org. (Accessed: 17 October 2012).
Kaunda-Arara, B., Rose, G.A., Muchiri, M.S. and Kaka, R. 2003. Long-term Trends in Coral Reef Fish Yields and Exploitation Rates of Commercial Species from Coastal Kenya. Western Indian Ocean Journal of Marine Science 2(2): 105-116.
Nakamura, Y. and Tsuchiya, M. 2008. Spatial and temporal patterns of seagrass habitat use by fishes at the Ryukyu Islands, Japan. Estuarine, Coastal and Shelf Science 76: 345-356.
Nakamura, Y., Shibuno, T., Lecchini, D., Kawamura, T. and Watanabe, Y. 2009. Spatial variability in habitat associations of pre- and post-settlement stages of coral reef fishes at Ishigaki Island, Japan. Marine Biology 156: 2413-2419.
National Park of American Samoa. 2008. Fishes of National Park of American Samoa Checklist of Fishes Family Name Listing. Available at: http://www.botany.hawaii.edu/basch/uhnpscesu/htms/npsafish/family/acanthur.htm. (Accessed: 21 April).
Ohman, M.C., Rajasuriya, A. and Olafsson, E. 1997. Reef fish assemblages in north-western Sri Lanka: distribution patterns and influences of fishing practices. Environmental Biology of Fishes 49: 45-61.
Randall, J.E. 2001a. Surgeonfishes of the world. Mutual Publishing and Bishop Museum Press, Hawai'i, Honolulu, Hawaii.
Reeson, P.H. 1983. The biology, ecology and bionomics of the surgeonfishes, Acanthuridae. In: J.L. Munro (ed.), Caribbean coral reef fishery resources, pp. 178-190.
Rhodes, K.L.,Tupper, M.H. and Wichilmel, C.B. 2008. Characterization and management of the commercial sector of the Pohnpei coral reef fishery, Micronesia. Coral Reefs 27: 443–454.
Walsh, W., Cotton, S., Carman, B., Livnat, L., Osada, K., Barnett, C., Tissot, B., Stevenson, T., Wiggins, C., Tarnas, D., Bourdon, K. and Peck, S. 2010. Report on the Findings and Recommendations of Effectiveness of the West Hawaii Regional Fishery Management Area. Department of Land and Natural Resources State of Hawaii, State of Hawaii.
Wantiez, L., Thollot, P. and Kulbicki, M. 1997. Effects of marine reserves on coral reef fish communities from five islands in New Caledonia. Coral Reefs 16(4): 215-224.
Werner, T.B. and Allen, G.R. 2000. A rapid marine biodiversity assessment of the Calamianes Islands, Palawan province, Philippines. RAP Bulletin of Biological Assessment 17. Conservation International, Washington, USA.
|Citation:||Choat, J.H., Abesamis, R., Clements, K.D., McIlwain, J., Myers, R., Nanola, C., Rocha, L.A., Russell, B. & Stockwell, B. 2012. Acanthurus blochii. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 02 October 2014.|