Ireland On-Line

    Tuesday 23 January 2007

    Nearly half the world's waterbird species are in decline, mostly due to rapid economic development and the effects of climate change, according to a global survey released today.

    The fourth annual Waterbird Population Estimate found that 44% of the 900 species globally had fallen in the past five years, while 34% were stable and 17% rising.

    Altogether, 12 families of birds have half or more of their global populations showing a decreasing trend, including storks, shoebills and plovers.

    The worst decreases occurred in Asia, where 62% of the waterbird populations had declined or become extinct. That was followed by a 48% decline in Africa, 45% in Oceania, 42% in South America, 41% in Europe and 37% in North America.

    Simon Delany, a waterbird conservation officer for Netherlands-based Wetlands International, which coordinated the survey, said the cause of the decline was a loss of wetlands either from economic and agriculture development or rising temperatures, which are blamed for worsening droughts and rising sea levels.

    The survey represents about 50,000 hours of field work done in 100 countries.

    "The most frequent known cause of population decrease is habitat destruction, often caused by unsustainable human activity," Delany said.

    "The frantic pace of economic development is clearly having adverse impacts on the environment, including numbers and population trends of waterbirds.

    "Human impacts such as urban sprawl, reclamation of wetlands, increase of pollution and hunting pressure can develop rapidly and conservation considerations are often not taken into account."

    Darters, screamers, rails, finfoots, jacanas, painted-snipes, stone curlews, seedsnipes and skimmers were other species that had gone into decline, the report said.

    Delany said the threats were especially visible in Asia, where mangroves were being destroyed to make way for shrimp and fish farms and wetland was increasingly being reclaimed for industrial estates and tourist resorts.

    South Korea, for example, has converted about half the country's 988,400 acres of tidal flats for commercial purposes while China has taken half its mangrove forests since 1949 for land reclamation and aquaculture.

    "Land reclamation is simply removing huge areas of wetlands, which means very large number of birds and other species have no where to live," Delany said. "Many of these birds are long-distant migrants so they need these places to feed. If there is nothing available for them, they can't survive."

    Delany and others said there were positive developments in the survey, especially in Europe and North America, where most bird populations were either stable or on the rise.

    He attributed that to stabilising human populations as well as greater environmental awareness, which had led to stronger regulations and greater protection of wetlands.

    Mike Crosby, research and data manager for Birdlife International, said the findings were what most bird experts would have expected and served as a reminder of the urgency to set aside the most threatened wetlands for protection.