The Loss of Species: Mangrove Extinction Risk and Geographic Areas of Global Concern

Abstract

Mangrove species are uniquely adapted to tropical and subtropical coasts, and although relatively low in number of species, mangrove forests provide at least US $1.6 billion each year in ecosystem services and support coastal livelihoods worldwide. Globally, mangrove areas are declining rapidly as they are cleared for coastal development and aquaculture and logged for timber and fuel production. Little is known about the effects of mangrove area loss on individual mangrove species and local or regional populations. To address this gap, species-specific information on global distribution, population status, life history traits, and major threats were compiled for each of the 70 known species of mangroves. Each species' probability of extinction was assessed under the Categories and Criteria of the IUCN Red List of Threatened Species. Eleven of the 70 mangrove species (16%) are at elevated threat of extinction. Particular areas of geographical concern include the Atlantic and Pacific coasts of Central America, where as many as 40% of mangroves species present are threatened with extinction. Across the globe, mangrove species found primarily in the high intertidal and upstream estuarine zones, which often have specific freshwater requirements and patchy distributions, are the most threatened because they are often the first cleared for development of aquaculture and agriculture. The loss of mangrove species will have devastating economic and environmental consequences for coastal communities, especially in those areas with low mangrove diversity and high mangrove area or species loss. Several species at high risk of extinction may disappear well before the next decade if existing protective measures are not enforced.

Growth of three subtropical mangrove species in response to varying hydroperiod in an experimental tank

“…Mangrove forests are important because they have the ability to improve ecological aspects such as organic carbon dynamics (Flores-Verdugo et al 1987, Bashan and Holguin 2002, Kristensen et al 2008) and primary productivity (Holguin et al 2001, Dittmar et al 2006, and they provide protection against hurricanes and tropical storms (Raven et al 1992, Gilman et al 2008, Komiyama et al 2008. Despite their ecological importance, mangrove forests around the world are constantly exposed to anthropogenic disturbances such as port development in the coastal zone, expansion of the agricultural frontier, and aquaculture expansion (Duke et al 2007, Polidoro et al 2010, Spalding et al 2010.…”

“…Los bosques de mangle son importantes porque tienen las facultades de mejorar aspectos ecológicos como la dinámica de carbono orgánico (FloresVerdugo et al 1987, Bashan y Holguin 2002, Kristensen et al 2008 y productividad primaria (Holguin et al 2001, Dittmar et al 2006, además actúan como zona de protección contra huracanes y tormentas tropicales (Raven et al 1992, Gilman et al 2008, Komiyama et al 2008. A pesar de su importancia ecológica, los bosques de mangle están bajo constante degradación a nivel mundial debido a disturbios antropogénicos como el desarrollo de puertos en la zona costera, la ampliación de la frontera agropecuaria y la expansión de la acuacultura (Duke et al 2007, Polidoro et al 2010, Spalding et al 2010.…”

Mangroves Response to Climate Change: A Review of Recent Findings on Mangrove Extension and Distribution

“…Based on biodiversity alone, mangrove forests provide at least US $1.6 billion each year in ecosystem services and support of coastal livelihoods worldwide (Polidoro et al 2010). However, by occupying the coastline, which includes areas of high population density, mangroves are under constant pressure from urban and agricultural expansion, diverse industrial activities, hydrological changes of river basins, spills of chemicals and eutrophication, despite its great importance in sustaining the coastal zone (Medina et al 2001, Valiela et al 2001, USGS 2004, Long et al 2014.…”

“…This loss will have devastating economic and environmental consequences for coastal communities due to the importance of these species for the livelihood of indigenous populations (Polidoro et al 2010).…”

I-C-SEA Change: A participatory tool for rapid assessment of vulnerability of tropical coastal communities to climate change impacts

“…The country is prone to climate impacts because of its small, densely populated islands that depend on their threatened coastal habitats. In spite of being known for their outstanding biodiversity, there are equally high risks for their destruction and loss (Duarte et al 1997;Polidoro et al 2010; Electronic supplementary material The online version of this article (doi:10.1007/s13280-015-0652-x) contains supplementary material, which is available to authorized users. Burke et al 2011;Primavera et al 2012;Sanciangco et al 2013).…”