20050618

Asian tsunami helped to spread alien species
[plant species, that is]

The Indian Ocean tsunami's devastating waves brought more than death to this island nation — they upset some of Sri Lanka's key ecosystems, the U.N. environmental agency warned Friday.

Nearly six months after the disaster that killed more than 31,000 people in Sri Lanka, studies have found that the tsunami waves have pushed seeds of so-called alien invasive species from their coasts farther inland on the tropical island, the United Nations Environment Program said.

"In some areas, including important national parks, the wave has encouraged the spread of alien invasive species, such as prickly pears and salt-tolerant mesquite," the agency said in a statement.

Neither species is native to Sri Lanka, but they existed in small numbers in limited coastal areas, said Gehan de Silva Wijeyeratne, the country's best-known nature expert. He did not say how the species first arrived in Sri Lanka.

"Now they can pose a threat to our ecosystem," he said. "Our local plants and animals have not co-evolved with these alien plants so when alien plants dominate in the ecosystem they will reduce the diversity of the local fauna and flora."

These are among the findings into the environmental impacts of the tsunami done by the U.N. agency and Sri Lankan Ministry of Environment and Natural Resources. The report confirms that in those areas with healthy coral reefs and mangroves, the impact of the devastating events the tsunami were significantly reduced.

"The tsunami in the Indian Ocean taught the world some hard, shocking but important lessons which we ignore at our peril," said Klaus Toepfer, UNEP's Executive Director.

"We learned in graphic and horrific detail that the ecosystems, such as coral reefs, mangroves and seagrasses which we have so casually destroyed are not a luxury. They are lifesavers capable of helping to defend our homes, our loved ones and our livelihoods from some of nature's more aggressive acts," he added. "It is therefore vital, that during the reconstruction of shattered coastlines and settlements, the environment is taken into account along with the economic and social factors."