The effort to restore mangroves in the Philippines is mostly wasted, because planters fail to select suitable sites for seedlings. Moreover, instead of restoring the original flora they destroy perfectly healthy habitats, reports Science magazine.

The Philippines have lost nearly 3/4 of their coastal mangrove forests over the last century. Mangroves grow in coastal waters and are an important part of the ecosystem. Settlers cleared them for development and ponds for fish farming.

Two decades ago conservation activists launched a campaign to reverse the trend. So far they’ve planted 44,000 hectares with mangrove seedlings, but it turns out their effort may have been in vain.

According to Maricar Samson and Rene Rollon of the University of the Philippines, many of the hundreds of millions of planted trees are doomed to die because the planters didn’t understand mangroves’ biological needs. They placed the seedlings in mudflats, sandflats, or sea-grass meadows – places with a nutrition deficit and strong currents or winds batter them. And what’s worse, the restoration damaged the perfectly healthy habitats that were there before the green activists came.

Researchers say mangrove planters need better guidance and more education in biology. They also call for converting abandoned or poorly managed fish ponds back to mangrove forests – although they admit owners would be reluctant to part with their land.