|Scientific Name:||Nypa fruticans|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||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) & Baker, W.J. (Palm Red List Authority)|
This species is widespread and can be locally common. There are some localized threats to this species from habitat loss and extraction, but this species is planted in many areas and is used for many goods and services. As a result, the population is very dynamic with declines in some regions and increases in others. There has been an estimated 20% decline in mangrove area within this species range since 1980. Mangrove species are more at risk from coastal development and extraction at the extremes of their distribution, and are likely to be contracting in these areas more than in other areas. It is also likely that changes in climate due to global warming will further affect these parts of the range. Although there are overall range declines in many areas, they are not enough to reach any of the threatened category thresholds. This species is listed as Least Concern.
|Range Description:||This species ranges from Sri Lanka and the Ganges Delta through to the west Pacific. In South and South-East Asia it is found in Bangladesh, Brunei Darussalam, Cambodia, China (Hainan Island), India, Indonesia, Japan (the most northern distribution is Iriomote Island), Malaysia, Myanmar, Singapore, Sri Lanka (where it also has a range extention due to planting), Thailand, and Viet Nam. In Australasia, it is found in northwest and northeast Australia, the Federated States of Micronesia, Guam, Palau, Papua New Guinea, Solomon Islands.
The species has been introduced to Cameroon and Nigeria in West Africa and to Panama in Central America and Trinidad and Tobago in the Caribbean. In much of its native range it has been planted and exists in large or small-scale plantations. It is unknown if inclusion of plantations would be representative of the natural range.
Native:Australia (Northern Territory, Queensland); Bangladesh; Brunei Darussalam; Cambodia; China (Hainan); Guam; India; Indonesia (Irian Jaya, Jawa, Kalimantan, Maluku, Sulawesi, Sumatera); Japan (Nansei-shoto); Malaysia (Peninsular Malaysia, Sabah, Sarawak); Micronesia, Federated States of; Myanmar; Northern Mariana Islands; Palau; Papua New Guinea (Bismarck Archipelago, North Solomons, Papua New Guinea (main island group)); Philippines; Singapore; Solomon Islands; Sri Lanka; Taiwan, Province of China; Thailand; Viet Nam
Introduced:Cameroon; French Polynesia (Society Is.); Nigeria; Panama; Trinidad and Tobago
|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 has a very dynamic population. It has experienced general declines due to localized threats throughout its range. This species has almost disappeared in the Indian Sundarbans due to reduced fresh water flow (Kathiresan pers. comm.). However, in some areas it is also increasing due to planting. In the Phillippines for example, other mangrove species have been cleared to plant this species, which may pose a threat to mangrove biodiversity (J. Primavera pers. comm.). In some parts of Africa where it has been introduced, it has become invasive and is considered a pest.|
|Habitat and Ecology:||
This species is found in the upstream estuarine zone in low, mid, and high intertidal regions (Robertson and Alongi 1992). It forms extensive belts along brackish to tidal freshwater creeks and rivers. It is very fast growing, especially in fresh water, and is a competitive species.
In Papua New Guinea, Nypa fruticans dominates vast areas of the upper Fly River and other south coast estuaries with high tide river water salinities of 1-10 o/oo (Robertson et al. 1991). The species occurs at similar positions in the Sunderbans Delta of India, which has a relatively high rate of sea-level rise, but this species is blocked from inland migration owing to coastal development, and its area and occurrence has been declining (K. Kathiresan pers. comm.)
|Systems:||Terrestrial; Freshwater; Marine|
As this species prefers more freshwater environments, hyper-saline conditions and strong wave action (including that caused by passing ships) can threaten this species. 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 20% decline in mangrove areas in countries within this species range since 1980 (FAO 2007).
Sea level rise is a major threat, especially to back mangroves that have no area in which to expand. Mangrove species with a habitat on the landward margin may be particularly vulnerable to sea-level rise if owing to coastal development their movement inland is blocked. In the Sunderbans Delta of India, for example, which has a relatively high rate of sea-level rise, provides insight to what may be common elsewhere as global sea levels rise (Mukherjee 1984). There, Nypa fruticans is blocked from inland migration owing to coastal development, and its area and occurrence has been declining (K. Kathiresan pers. comm.)
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.|
|Citation:||Ellison, J., Koedam, N.E., Wang, Y., Primavera, J., Jin Eong, O., Wan-Hong Yong, J. & Ngoc Nam, V. 2010. Nypa fruticans. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 26 May 2013.|
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