The authors gratefully acknowledge the very valuable information and insights provided by numerous mangrove and forest inventory specialists worldwide. A list of people contacted is found in Annex 3.
ASFA |
Aquatic Sciences and Fisheries Abstracts |
FAO |
Food and Agriculture Organization of the United Nations |
FORIS |
Forestry Information System |
FRA |
Forest Resources Assessment |
GFRA |
Global Forest Resources Assessment |
ISME |
International Society for Mangrove Ecosystems |
ITTO |
International Tropical Timber Organization |
SIDS |
Small Island Developing States |
UNEP |
United Nations Environment Programme |
High population pressure in coastal areas has led to the conversion of many mangrove areas to other uses and numerous case studies describe mangrove losses over time. However, scarce information exists on the current status and trends in mangrove area extent at the global level.
This document describes a recent initiative by the Food and Agriculture Organization of the United Nations (FAO) which aims at facilitating access to comprehensive information on the current and past extent of mangroves in all countries and areas in which they exist. This initiative builds on an earlier assessment by FAO/UNEP in 1980, the recent FAO Global Forest Resources Assessment 2000 (FRA 2000) and an extensive literature search.
More than 2800 national and sub-national data sets have, so far, been collected, covering 121 countries and areas where mangroves are known to exist, with the earliest estimates dating back to 1918. An updated list of the most recent, reliable estimate for each country has been compiled. Regression analyses based on earlier data provided revised estimates for 1990 and 1980 and an extrapolated estimate for 2000 for each country.
Changes in definitions and methodologies overtime make it difficult to compare results from different assessments and the extrapolation to 2000 was constrained by the lack of recent information from a number of countries. This estimate is thus indicative only and is likely to change when results from on-going and future assessments become available.
The results of the present study suggest that the current mangrove area worldwide has now fallen below 15 million ha, down from 19.8 million ha in 1980. It also indicates that mangrove deforestation continues, albeit on a slightly lower rate in the 1990s (1.1 percent per annum) than in the 1980s (1.9 percent per annum), reflecting the fact that most countries have now banned the conversion of mangroves for aquaculture purposes and require environmental impact assessments prior to large-scale conversion of mangroves for other uses.
The study concludes that better information on both the extent and the condition of mangroves is needed as an aid to policy and decision making aimed at the conservation, management and sustainable use of the world’s remaining mangrove ecosystems.