|Scientific Name:||Brownlowia tersa|
|Species Authority:||(L.) Kosterm.|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor/s:||Kathiresan, K., Salmo III, S.G., Fernando, E.S., Peras, J.R., Sukardjo, S., Miyagi, T., Ellison, J., Koedam, N.E., Wang, Y., Primavera, J., Jin Eong, O., Wan-Hong Yong, J. & Ngoc Nam, V.|
|Reviewer/s:||Polidoro, B.A., Livingstone, S.R. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)|
This species has a disjunct range, is common within at least parts of its range, and is fast-growing. This species is threatened by habitat loss from coastal development, erosion, and the construction of shrimp and fish ponds throughout its range. Although there is no data available on mangrove area loss over three generation lengths (60 years), mangrove loss within this species range is estimated to be approximately 26% since the 1980s. There is reason to believe that this species may quality for a threatened category in the near future due to the fact that it occurs only on the landward margin where it is the most vulnerable to coastal development and human activities. It is listed as Near Threatened.
|Range Description:||This species has a disjunct range. It is found along the eastern coast of India and the Andaman and Nicobar Islands, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia (Molluccas, Irian Jaya, Kalimantan, Natuna Island), Singapore, Philippines, and Brunei.|
Native:Bangladesh; Brunei Darussalam; Cambodia; India; Indonesia; Malaysia; Myanmar; Philippines; Singapore; Thailand
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – northwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is common in many parts of its range, but is considered very rare in the far western portion of its range. In India for example, there are only approximately 2,500 mature individuals which are restricted to the eastern coast of India and the Andaman Islands.|
|Habitat and Ecology:||This species is found along tidal creeks, canals, and shallow channels. This is a brackish water species that grows to two metres, and rarely to five metres. It is fast growing and found in pure stands.|
This species is found primarily on the landward marigin, and therefore it is more threatened by human activities and coastal development than other more seaward mangrove species. It is especially threatened by coastal development, including fish and shrimp pond development throughout its range. In India, it is primarily threatened by loss of habitat from erosion and anthropogenic development. Although local estimates are uncertain due to differing legislative definitions of what is a 'mangrove' and to the imprecision in determining mangrove area, current consensus estimates of mangrove loss in the last quarter-century report an approximately 26% decline in mangrove areas in countries within the primary part (Myanmar, Indonesia, Malaysia, Philippines, Thailand, Cambodia) of this species range since 1980 (FAO 2007).
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. 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.
FAO. 2007. The World's Mangroves 1980-2005. FAO Forestry Paper 153. Forestry Department, Food and Agriculture Organization of the United Nations (FAO), Rome.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.2). Available at: http://www.iucnredlist.org. (Accessed: 29 June 2010).
|Citation:||Kathiresan, K., Salmo III, S.G., Fernando, E.S., Peras, J.R., Sukardjo, S., Miyagi, T., Ellison, J., Koedam, N.E., Wang, Y., Primavera, J., Jin Eong, O., Wan-Hong Yong, J. & Ngoc Nam, V. 2010. Brownlowia tersa. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 24 April 2014.|