|Scientific Name:||Acropora russelli|
|Species Authority:||Wallace, 1994|
|Red List Category & Criteria:||Vulnerable A4c ver 3.1|
|Assessor(s):||Aeby, G., Lovell, E., Richards, Z., Delbeek, J.C., Reboton, C. & Bass, D.|
|Reviewer(s):||Livingstone, S., Polidoro, B. & Smith, J. (Global Marine Species Assessment)|
This species is widespread and uncommon throughout its range. However, it is particularly susceptible to bleaching, disease, and extensive reduction of coral reef habitat due to a combination of threats. Specific population trends are unknown but population reduction can be inferred from declines in habitat quality based on the combined estimates of both destroyed reefs and reefs at the critical stage of degradation within its range (Wilkinson 2004). Its threat susceptibility increases the likelihood of being lost within one generation in the future from reefs at a critical stage. Therefore, the estimated habitat degradation and loss of 43% over three generation lengths (30 years) is the best inference of population reduction and meets the threshold for Vulnerable under Criterion A4c. It will be important to reassess this species in 10 years time because of predicted threats from climate change and ocean acidification.
|Range Description:||This species is found in the central Indo-Pacific, north and west Australia. Also found in the Philippines (Fenner pers. comm.). Found in Timor Sea, Indonesia (Richards pers. comm.) and Sri Lanka (Wallace pers. comm.).|
Native:Australia; India; Indonesia; Malaysia; Philippines; Singapore; Sri Lanka; Thailand
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – northwest; Pacific – western central
|Lower depth limit (metres):||30|
|Upper depth limit (metres):||15|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This is an uncommon species. It was found at two of six regions in Indonesia (Wallace et al. 2001).
There is no species specific population information available for this species. However, there is evidence that overall coral reef habitat has declined, and this is used as a proxy for population decline for this species. This species is particularly susceptible to bleaching, disease, and other threats and therefore population decline is based on both the percentage of destroyed reefs and critical reefs that are likely to be destroyed within 20 years (Wilkinson 2004). We assume that most, if not all, mature individuals will be removed from a destroyed reef and that on average, the number of individuals on reefs are equal across its range and proportional to the percentage destroyed reefs. Reef losses throughout the species' range have been estimated over three generations, two in the past and one projected into the future.
The age of first maturity of most reef building corals is typically three to eight years (Wallace 1999) and therefore we assume that average age of mature individuals is greater than eight years. Furthermore, based on average sizes and growth rates, we assume that average generation length is 10 years, unless otherwise stated. Total longevity is not known, but likely to be more than ten years. Therefore any population decline rates for the Red List assessment are measured over at least 30 years. See the Supplementary Material for further details on population decline and generation length estimates.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This species occurs in shallow, tropical reef environments. It is found on sheltered reef slopes and on deep sandy reef slopes (Richards pers. comm.). It is found in free-living colonies or matted assemblages, intertwined with Leptoseris papyracea (Dana 1846). Found in assemblages among Leptoseris and other species. This species is found from 15-30 m.|
Members of this genus have a low resistance and low tolerance to bleaching and disease, and are slow to recover.
Acanthaster planci, the crown-of-thorns starfish, has been observed preferentially preying upon corals of the genus Acropora (Colgan 1987). However, this species not likely to be affected by COTS.
Found in inter-reef areas that may be trawled.
In general, the major threat to corals is global climate change, in particular, temperature extremes leading to bleaching and increased susceptibility to disease, increased severity of ENSO events and storms, and ocean acidification.
Coral disease has emerged as a serious threat to coral reefs worldwide and a major cause of reef deterioration (Weil et al. 2006). The numbers of diseases and coral species affected, as well as the distribution of diseases have all increased dramatically within the last decade (Porter et al. 2001, Green and Bruckner 2000, Sutherland et al. 2004, Weil 2004). Coral disease epizootics have resulted in significant losses of coral cover and were implicated in the dramatic decline of acroporids in the Florida Keys (Aronson and Precht 2001, Porter et al. 2001, Patterson et al. 2002). In the Indo-Pacific, disease is also on the rise with disease outbreaks recently reported from the Great Barrier Reef (Willis et al. 2004), Marshall Islands (Jacobson 2006) and the northwestern Hawaiian Islands (Aeby 2006). Increased coral disease levels on the GBR were correlated with increased ocean temperatures (Willis et al. 2007) supporting the prediction that disease levels will be increasing with higher sea surface temperatures. Escalating anthropogenic stressors combined with the threats associated with global climate change of increases in coral disease, frequency and duration of coral bleaching and ocean acidification place coral reefs in the Indo-Pacific at high risk of collapse.
Localized threats to corals include fisheries, human development (industry, settlement, tourism, and transportation), changes in native species dynamics (competitors, predators, pathogens and parasites), invasive species (competitors, predators, pathogens and parasites), dynamite fishing, chemical fishing, pollution from agriculture and industry, domestic pollution, sedimentation, and human recreation and tourism activities.
The severity of these combined threats to the global population of each individual species is not known.
All corals are listed on CITES Appendix II. Parts of the species’ range fall within Marine Protected Areas.
Recommended measures for conserving this species include research in taxonomy, population, abundance and trends, ecology and habitat status, threats and resilience to threats, restoration action; identification, establishment and management of new protected areas; expansion of protected areas; recovery management; and disease, pathogen and parasite management. Artificial propagation and techniques such as cryo-preservation of gametes may become important for conserving coral biodiversity.
|Citation:||Aeby, G., Lovell, E., Richards, Z., Delbeek, J.C., Reboton, C. & Bass, D. 2008. Acropora russelli. The IUCN Red List of Threatened Species 2008: e.T133164A3609729. http://dx.doi.org/10.2305/IUCN.UK.2008.RLTS.T133164A3609729.en . Downloaded on 08 October 2015.|
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