|Scientific Name:||Avicennia integra|
|Red List Category & Criteria:||Vulnerable B1ab(ii,iii) ver 3.1|
|Reviewer(s):||Polidoro, B.A., Livingstone, S.R. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)|
This species has a very restricted range in Australia, and has very specific riverine-estuarine habitat requirements. It range is severely fragmented, and it is only found in 15 locations with an estimated population size of less than 5,000 mature individuals and an extent of occurrence of less than 20,000 km². This species is experiencing continued decline in both area of occupancy and in the number of mature individuals by continued urban development in the western part of its range. Although extensive historical data is not available, it is very likely that this species has experienced a high population decline. It is therefore listed as Vulnerable under criterion B.
|Range Description:||This species has a restricted range, and is endemic to northern Australia. It is found in only 15 locations (riverine-estuaries), and has an extent of occurrence estimated to be less than 20,000 km².|
|FAO Marine Fishing Areas:||
Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||It is estimated that there are only a few hundred individuals in each of the 15 locations where it is found. The global population is therefore estimated to be between 3,000 and 5,000 mature individuals.|
|Habitat and Ecology:||This species is found in the intermediate estuarine zone in the low intertidal region. It is only found in low intertidal zone and in the mid-upstream position of larger catchments or riverine-affected estuaries. It grows on soft-intertidal mud banks of convex meandering riverbanks (accreting zone). This species is a tree or shrub, 2-7 m tall. This species has a high tolerance to hypersaline conditions (Tomlinson 1986).|
This species is found in a remote area of northern Australia where the climate appears to be getting increasingly wet as the local climate changes. This may be potentially favorable for the persistance of the species. However, this species is threatened by continued loss of habitat and area of occupancy due to urban development in the western part of its range (near Darwin).
Direct use of mangroves in is not common in Australia, and vast areas of mangrove remain in a pristine state. In the past, European colonists cleared areas of mangroves for community development. Currently, mangroves are being cleared for urban development, ports, airports, and tourist resorts, but the overall impact on Australian mangroves is low (Spalding et al. 1997).
All mangrove ecosystems occur within mean sea level and high tidal elevations, and have distinct species zonations that are controlled by the elevation of the substrate relative to mean sea level. This is because of associated variation in frequency of elevation, salinity and wave action (Duke et al. 1998). With rise in sea-level, the habitat requirements of each species will be disrupted, and species zones will suffer mortality at their present locations and re-establish at higher elevations in areas that were previously landward zones (Ellison 2005). If sea-level rise is a continued trend over this century, then there will be continued mortality and re-establishment of species zones. However, species that are easily dispersed and fast growing/fast producing will cope better than those which are slower growing and slower to reproduce.
In addition, mangrove area is declining globally due to a number of localized threats. The main threat is habitat destruction and removal of mangrove areas. Reasons for removal include cleared for shrimp farms, agriculture, fish ponds, rice production and salt pans, and for the development of urban and industrial areas, road construction, coconut plantations, ports, airports, and tourist resorts. Other threats include pollution from sewage effluents, solid wastes, siltation, oil, and agricultural and urban runoff. Climate change is also thought to be a threat, particularly at the edges of a species range. Natural threats include cyclones, hurricane and tsunamis.
|Conservation Actions:||There are no conservation measures specific to this species, but its range may include some marine and coastal protected areas. Continued monitoring and research is recommended, as well as the inclusion of mangrove areas in marine and coastal protected areas.|
Duke, N. 2006. Australia's Mangroves. The authoritative guide to Australia's mangrove plants. University of Queensland, Brisbane, Australia.
Duke, N. C., Ball, M.C. and Ellison, J.C. 1998. Factors influencing biodiversity and distributional gradients in mangroves. Global Ecology and Biogeography Letters 7: 27-47.
Ellison, J.C. 2005. Holocene palynology and sea-level change in two estuaries in Southern Irian Jaya. Palaeogeography, Palaeoclimatology, Palaeoecology 220: 291-309.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.2). Available at: http://www.iucnredlist.org. (Accessed: 29 June 2010).
Robertson, A.I. and Alongi, D.M. 1992. Tropical Mangrove Ecosystems. American Geophysical Union, Washington, DC.
Spalding, M.D., Blasco, F. and Field, C.D. (eds). 1997. World Mangrove Atlas. The International Society for mangrove Ecosystems, Okinawa, Japan.
Tomlinson, P.B. 1986. The Botany of Mangroves. Cambridge University Press, New York.
|Citation:||Duke, N. 2010. Avicennia integra. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 25 July 2014.|
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