Thin strips of mangrove clusters - the nursery habitat for fish and migratory seabirds in the Gulf - are the country's most vital ecological resource and the UAE has undertaken a restoration project to protect some 40 square kilometres of the trees, which grow in brackish coastal waters on leggy roots. But while Abu Dhabi's Urban Planning Council has identified and reacted to the need to preserve the mangroves, commendably large-scale efforts elsewhere in the world appear to be backfiring.
The most notable example is a seeding strategy in the Philippines, where 70 per cent of the archipelago's mangroves have been lost to deforestation since the 1950s. Their method of seeding has not only been ineffective, according to Maricar Samson and Rene Rollon, biologists at the University of the Philippines, it has been potentially harmful to the environment. In one of the world's most intensive mangrove reforestation projects, only 20 per cent of the hundreds of millions of seedlings planted each year are surviving.
"For one hectare we studied, there were 10,000 seedlings planted, but we had pictures to show that 9,000 seedlings were lost and died," said Ms Samson. The major contributing factor, she explained, seemed to be the misguided idea that restoration projects simply required indiscriminate seeding, without having a proper understanding of mangrove hydrology. "Our paper provides evidence that lots of money and effort is being wasted on some very poor growth performance for mangroves, and this is due to the fact that they are being planted in the wrong places," she said, speaking from Quezon City.
For example, the broad-leafed Rhizophora species is having trouble surviving in the Philippines because it is being planted on the seafront, where the seedlings are more susceptible to wind and waves, whereas it would be more likely to thrive in mid-forest, say the researchers. Mangroves, which are deposited along banks, created unique ecosystems because of their intricate root systems and an ability to protect the coast from erosion, monsoon winds and typhoons, said Ms Samson.
"They are also important to the Philippines because they yield major sources of fisheries products such as crabs, lobsters and oysters," she said. As a result of human settlement over the past century, coastal dwellers have severely reduced many mangrove areas, exploiting the trees for fuel and converting the brackish-water mangrove habitat to ponds for fish farming. In an effort to reverse a trend that has been under way for the past two decades, conservation groups began replanting some 44,000 hectares. But after conducting surveys of more than 70 sites, it became clear to Ms Samson and Mr Rollon that the ecological gains of converting mudflats, sand flats and seagrass meadows into mangrove forests was uncertain.
Those zones are defined in the pair's paper as "non-mangrove" areas, unable to support mangroves with the necessary nutrients and environmental conditions. Many trees were "dismally stunted" and the few that survived did so only "through stubborn, expensive replanting". In the Philippines, there has been increasing pressure from non-governmental organisations and the scientific community to concentrate planting where there is the most available space - the country's many idle fish ponds.
"It would be far more appropriate to reforest some of the former mangrove areas, which are currently utilised as brackish-water fish ponds," says the paper. Intensifying efforts to return brackish-water ponds to their original purpose would be more effective than converting "inappropriate sites", such as seagrass beds. Ms Samson also noted that the practice of planting on sites incompatible with mangrove species had a second unforeseen consequence: the corresponding loss of mudflats and sand flats. At low and high tides, says the paper, those non-mangrove areas should serve as feeding grounds for shorebirds and some species of fish.
The bottom line was that there must be better guidance for plantations, which depended on the political will of local and national governments. Abu Dhabi has already recognised that the seagrass beds and mangroves surrounding the city "are the most important ecological resources in the entire country", according to the Urban Planning Council's 2030 plan; it is believed that the capital's mangroves - situated in the shallow, sandy tidal flats where the desert meets the Gulf - can help to curb the degradation of land in the arid environment.
But not all is well, even here. Although some developers have been careful to work around sensitive ecosystems, ongoing development and rapid urbanisation along the coast pose threats to habitats. And recognising the importance of the country's wetlands may not, by itself, enough. According to the Environment Agency - Abu Dhabi website, "relatively few habitat restoration programmes have been undertaken".
mkwong@thenational.ae
