for National Geographic News
Spectacular limestone karsts in Southeast Asiahavens for many unique and endangered speciesare being destroyed by quarrying and other human activities, a new study warns.
Rare bats, insects, mollusks, cave fish, rodents, and other animals face the threat of extinction if the region's limestone karsts aren't granted better protection, researchers say.
The number of endangered karst-dwelling species has been seriously underestimated, the study adds.
Among Southeast Asia's most recognizable natural features, limestone karsts were formed millions of years ago by calcium-secreting marine organisms such as corals.
Erosion has sculpted these formations into rocky outcrops with cliffs, caves, and underground rivers. The karsts rise from tropical forests or from the sea as sheer-sided islands.
Writing in the latest issue of the journal BioScience, a team of biologists from the National University of Singapore describe these habitats as "arks of biodiversity."
But growing demand for limestone for the construction industry and other development has imperiled karst wildlife and led to extinctions, the researchers warn.
They also highlight threats to karsts from logging activity and land clearance for agriculture and development.
"Many species extinctions have probably gone unnoticed on karsts that were destroyed before they could be sampled," the team writes.
Karsts in the Pahang and Sabah regions of Malaysia have been completely leveled by mining companies, says Reuben Clements, lead author of the study (map of Malaysia).
"As a result, at least a couple of site-endemic snail species [species found nowhere else in the world] are presumably extinct," he said.
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