Asia's karst landscapes are yielding new biological discoveries at an astonishing rate, yet the majority of species found here remain unknown (and unloved) by the wider world. With limestone quarrying threatening these fragile ecosystems, is there anything we can do to stem the tide of unnoticed extinctions?
Regional Director at Fauna & Flora International (FFI), Dr Tony Whitte, shares his grave concern for the wondrous and diverse lifeforms that lurk in the darkness of Asia's karst landscapes.
Asia's karst landscapes are yielding new biological discoveries at an astonishing rate, yet the majority of species found here remain unknown (and unloved) by the wider world. With limestone quarrying threatening these fragile ecosystems, is there anything we can do to stem the tide of unnoticed extinctions?
At the end of last year a new fish Draconectes narinosus, whose name derives from the Greek words for dragon and swimmer, was revealed to the world. It is known only from a specific lake in one small cave on a diminutive and contorted limestone island in North Vietnam's World Heritage Site of Ha Long Bay.
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Evolving in isolation and the dark, it has no eyes, markings, or scales. It is so different from anything seen before that it has been recognized not just as a new species, but as a new genus.
Although exciting, in the world of limestone biodiversity this is not exceptional. For those who care to look, the limestone hills and caves that characterize Asia's karst landscapes reveal astonishing levels of biodiversity. A large proportion of animals collected during surveys are new to science.
This is partly because caves are visited infrequently, but also as a result of the highly alkaline nature of limestone hills, dry soils and the presence of caves. This combination creates conditions which require animals (and indeed plants) to adapt and evolve. As with the cave fish, some of these species are confined to single hills or a particular cave systems because they are no longer able to cross the non-limestone habitats that lie between.
Alien world of caves
In the darkness, eyes are useless, colour and markings pointless, and flight downright dangerous. Thus many cave species (such as fish, shrimps, woodlice, millipedes and beetles) have lost these features and abilities, and instead have developed long antennae and legs which allow them to "feel" their way around.
With no light for photosynthesis there are no plants, so the energy to sustain the ecosystem has to come from elsewhere – either from the faeces (guano) produced by echo-locating birds and bats, or from nutrients carried in by cave rivers and by water dripping down from the world above.
The cave environment is generally quite stable and many species will perish quickly if the high humidity and darkness change – such as when blasting in a quarry occurs. More mobile cave residents such as bats can fly away, but the end is heralded for most cave species when blasting breaks through. And because so many species are endemic to a single cave or hill, quarrying – even in a small area – can easily result in the extinction of one or many species.
Limestone quarrying
With such extinctions taking place, there might be an expectation that more attention would be focused on limestone quarrying for the cement industry, an activity which causes most damage to karst ecosystems; unfortunately, that is not the case.
It's difficult to find good examples of cement quarry environmental impact assessments that take into account the full spectrum of karst biodiversity. This suggests that no company has yet done such work with an awareness of the extremely high levels of endemism in the ecosystems it is destroying. Although one global cement company has done some retrospective work with Fauna & Flora International, FFI is not yet permitted to discuss openly the significant findings, successes or lessons.
Uncharismatic fauna
It's problematic that many of the limestone species in greatest need of conservation are relatively small and little-known invertebrates - insects, crabs, shrimps, spiders, woodlice, millipedes, snails, etc. Very few have been properly assessed for the authoritative IUCN Red List of Threatened Species, and even fewer have been given any form of local or national protection.
Unfortunately, this means that a prudent cement company may complete the normal precautionary checklists, but its planned quarry could still be responsible for global extinctions.
Continue reading at The Ecologist
Cave with Water Via Shutterstock
