|Scientific Name:||Avicennia bicolor|
|Red List Category & Criteria:||Vulnerable A2cd ver 3.1|
|Reviewer(s):||Polidoro, B.A., Livingstone, S.R. & Carpenter, K.E. (Global Marine Species Assessment Coordinating Team)|
This is a species is restricted to the Eastern Pacific, and is found in dry muddy flats, which are commonly cleared for urban development, aquaculture, and livestock. Based on a yearly reduction of 1.4 % between 1980 and 2000, there has been an estimated 31 - 42 % loss in mangrove area within its range over the past 30 years. Decline over a period of three generation lengths (120 years) is likely to be much higher, however, little data exists for this time period.This species is listed as Vulnerable under Criterion A. There is known continuing decline from altered land use and exploitation, and with more historical data, this species may qualify for a higher threat category.
|Range Description:||This species is found in the Eastern Tropical Pacific from Mexico to Colombia.|
Native:Colombia; Costa Rica; El Salvador; Guatemala; Honduras; Mexico; Nicaragua; Panama
|FAO Marine Fishing Areas:||
Pacific – eastern central; Pacific – southeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species has experienced population declines of aproximately 31% over the past 30 years based on total loss of mangrove habitat throughout its range (FAO 2007).|
|Habitat and Ecology:||This species is a canopy tree at 15 m height, and occurs in relatively dry, flat areas compared to other mangroves. It is found in the down-stream high intertidal region where river mouths meet the sea. This species has a high tolerance to hypersaline conditions.|
|Systems:||Terrestrial; Freshwater; Marine|
|Use and Trade:||This species is harvested for fuelwood.|
This species has a limited range in the Eastern Pacific. Throughout its distribution, it occurs in areas that are commonly cleared for cattle grazing and other types of farming. Cattle that feed under mangroves reduce regeneration capacity and damage the root structure and leaves of the mature trees. In addition, its habitat (dry mud flats) is commonly developed by people, resulting in extensive removal of mangroves in these areas. Similarly, it is a species that lives in a high risk area for urban and aquaculture deveopment. Over the last 30 years (1980 to 2005) there has been an estimated reduction of at least 31% (FAO 2007), but as high as 42% based on a yearly reduction of 1.4% between 1980 and 2000 (Duke et al. 2007) in mangrove area within its range.
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:||Duke, N. 2010. Avicennia bicolor. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 21 October 2014.|