Assessment and management of mangrove ecosystems in developing countries

Abstract

There is limited information available on the status of and threats to mangroves in developing countries in the Asia-Pacific region. In the recent years, there has been a significant increase in scientific and volunteer surveys. However, this information is usually not well integrated with information on human activities that have the potential to contribute to the degradation of these ecosystems. A project "Coastal Habitats at Risk" is being developed jointly by the United Nations University (UNU) and the World Resources Institute, and in partnership with UNESCO and the International Society for Mangrove Ecosystems (ISME), in an effort to ameliorate this situation through standardized assessment of anthropogenic threats to mangroves in East and Southeast Asia. The geographic focus of the project includes Brunei, China, Cambodia, Indonesia, Malaysia, Myanmar, the Philippines, Singapore, Taiwan, Thailand and Vietnam. Threats from pollution, over-harvesting, aquaculture development, boating/shipping, flooding/freshwater input, siltation and other coastal development are examined with this map-based analysis. The study particularly emphasizes information regarding the human element of these ecosystems, with an eye towards community-based management and action. A geographic information system (GIS)-based tool will be developed to examine different coastal development and management scenarios and their implications for mangrove health, diversity and value. The results will serve as an indication of the threats to these ecosystems, not as an actual measure of degradation. This information generation can be seen as a first step toward assessing global needs for the world's mangrove ecosystems that to date remain largely unassessed. The analysis is intended to recommend policies, participatory approaches and management strategies to promote integrated coastal ecosystem approaches. It will help fill an information void through much-needed policy guidance on management and priority setting.

The Asian Tsunami’s Havoc and Death Toll: Nature’s Wrath or Human Shortsightedness?

“…Here we assume that displacement takes the form of a 100-km-wide delta function in which half of the zone is lifted and half is depressed. The magnitude is similar to that estimated for the recent Sumatra tsunami, with instantaneous, initial upward and downward displacements of +7.2 m and -3.5 m, respectively (Yalciner et al, 2004 (Adeel & Pomeroy, 2002) A coral reef can affect wave propagation and development by presenting an abrupt change in bathymetry and through increased bottom roughness. To model the former effect, at any grid point where a reef is present, the bottom depth is replaced by a step that rises to 1 m below the surface.…”

Temporal mangrove dynamics in relation to coastal development in Pacific Panama

“…Assuming that the rate of change in mangrove area was constant between years, the rates of loss during 1997-2002 were high, up to 20% per year in zones 1 and 3, although actual rates for 1998-1999 when the construction took place would no doubt be much higher. Ramírez-Garcia et al (1998) concluded the rate of loss seen in Mexico of 1.4% annually was high and Adeel and Pomeroy (2002) notes that declines of 2-8% per year were fast. Dahdouh-Guebas and Koedam (2002) explain that it is possible to incorporate previous maps of past mangrove extent with current field data on vegetation structure to gain insight into current and future mangrove dynamics.…”

Assessment of Physico-chemical Characteristics of Mangrove Region in the Krishnapatnam Coast, India

“…Mangrove forests have the highest productivity among coastal wetlands after coral reefs. Around 90% of all marine organisms spend some portion of their life cycle within the mangrove ecosystem (Adeel and Pomeroy, 2002). Mangrove ecosystem commands the highest importance because of its biological productivity and specialized diversity.…”