Mangroves Key To Saving Lives in the Philippines

ScienceDaily 21 Jul 08;

The replanting of mangroves on the coasts of the Philippines could help save many of the lives lost in the 20-30 typhoons that hit the islands annually.

This is one of the numerous reasons for the ‘urgent need for immediate and massive mangrove replanting’ that J.H. Primavera from the Southeast Asian Fisheries Development Center and J.M.A. Esteban from De La Salle University, both in the Philippines.

The study presents an analysis on a range of programs demonstrating that low-cost locally led projects have a much higher rate of success than high-cost government-led projects.

The mangrove forests along the Philippines’ 36,300 km of coastline play an important role in fisheries, forestry and wildlife as well as providing protection from typhoons and storm surges, erosion and floods. In the last century, they have declined from 450,000 ha to 120,000 ha, mostly due to their development into culture ponds. This has led to many replanting initiatives ranging from small community projects to large scale international development assistance programs. During this time planting costs have escalated from $100/ha to >$500/ha, mainly due to the overhead costs of large-scale projects. Unfortunately, despite heavy funding, the majority of these replanting schemes have been unsuccessful with only 10-20 percent of the mangroves replanted surviving.

In a comparison of a number of replanting initiatives, the authors found that the most successful projects had been low budget and locally led. One World Bank-sponsored project costing $38 million for coastal and nearshore fisheries (in addition to agriculture, forestry, livelihood and infrastructure subprojects) reported only a 35 percent survival rate for the mangroves planted. Conversely, a small £23,100 project implemented by a local government unit in co-operation with a people’s organization had a mangrove survival rate of 97 percent. Primavera and Esteban point out that the community involved had a shared interest in the survival of the mangroves and lived next to the plantation site therefore making maintenance easy.

They also noted a distinct lack of ecological knowledge as the wrong species of mangrove is consistently being planted in inappropriate sites. The sheltered areas which have been largely converted to fishponds were historically home to the mangrove forests. These ponds are theoretically covered by legal title if privately owned. This has led to the most popular species of mangrove, Rhizophora, being planted on exposed coastlines, where there are no ownership issues, despite its inability to withstand wave action.

The authors point out that many of these government-leased ponds have no legal basis and many are underutilized or have been abandoned. They challenge the Philippine government to ‘muster enough political will to make abandoned, undeveloped and otherwise illegal culture ponds available for mangrove rehabilitation’. Planting in these more appropriate sites, together with the use of hardier species such as S. alba and A. marina in more exposed areas, would have a significant effect on survival rates.

Primavera and Esteban conclude that the ecological benefits of mangrove rehabilitation involve planting the correct species on suitable sites, the involvement and commitment of the community and grant of tenure. Funding appears to be of secondary importance.

How to replant a mangrove forest: local, low-cost initiatives prove most successful
Jeremy Hance, mongabay.com 23 Jul 08;

Mangrove replanting and rehabilitation has become a widespread and important environmental initiative worldwide. Mangrove forests play key ecological roles, including sustaining fish populations and other wildlife, preventing erosion along coastlines, and acting as an overall carbon sink. Furthermore, mangroves have received attention lately for their role in providing an effective buffer against typhoons. In light of the many replanting initiatives now occurring, researchers J.H. Primavera and J.M.A. Esteban conducted a study of the overall effectiveness of different mangrove rehabilitation schemes. Their findings show that small, local, and generally cheaper initiatives have a higher success rate over large costly government and international programs.

The researchers chose the Philippines as their subject area. A nation of over 7,000 islands, the Philippines is a prime place for mangrove replanting, since the country has cut down over two-thirds of its mangroves in the past century. Most of this was due to fish and shrimp culture ponds, which now cover 232,000 hectares, compared with the 120,000 hectares of remaining mangroves.

Comparing eight different mangrove replanting initiatives in the Philippines, the authors found a lot of money was being spent on programs with low success rates: most initiatives showed only a 10-20 percent survival rate of planted mangroves. A World Bank project has spent 38 million on various coastal projects, including replanting mangroves, but despite the funds spent, their success rate—35 percent—was only slightly higher than average. Local programs with community-involvement have proven far more successful; one local government program reported a survival rate of 97 percent and spent a bargain-rate of just over 23,000 pounds ($45,000). Costs were cut and the survival rate raised, because adjacent communities invested time and energy into maintaining the mangroves.

A lack of knowledge also plagued larger initiatives. Sites that had never seen mangroves before were planted with poor success. A popular species, Rhizophora, was planted on sandy open coasts, in favor of two species more suited to that environment. Not being able to tolerate ocean waves, the trees did not survive.

A lack of political willpower has also proven paramount in the Philippines' unsuccessful mangrove programs. Most of the suitable areas for mangroves are now culture ponds; some of these ponds are abandoned or underused, yet so far the government has failed lacked the political will to take-back such areas for mangrove cultivation. Instead, they continue to plant mangroves on seagrass beds and tidal flats where mangroves have never survived.

The authors believe that the Philippines is in 'urgent need for immediate and massive mangrove replanting'. To create an effective barrier against typhoons and a stable environment, the authors suggest implementing a plan that would make the ratio of mangroves to culture ponds 4 to 1, where now culture ponds possess nearly double the land of mangroves. For a nation that sees 20-30 typhoons a year, mangroves could save lives and mitigate property damage. For example, in June of this year, the Philippines was hit by Typhoon Fengshen which destroyed over 50,000 homes, cost over 4.27 billion pesos, and killed 598 people.