Freshwater species in Indo-Burma region under threat

An assessment of 2,515 described freshwater species in the Indo-Burma region by the International Union for Conservation of Nature (IUCN) and partners has revealed that 13% of these species are threatened with extinction. The report comes at a time when large scale hydrological development is underway, or is proposed, throughout this region which is known for its exceptionally high diversity of freshwater species.

Brotia armata, a species  from central Thailand Photo: Andreas Helmenstein

This IUCN Red List of Threatened Species™ assessment details the locations and status of all described species of freshwater fish, molluscs, odonates, crabs, and selected families of aquatic plants within each of the 1,082 individual river or lake sub-catchments across the region. As the most comprehensive assessment yet of freshwater species in this global biodiversity hotspot, it provides valuable information that can help mitigate and minimize the impact of ongoing and future hydrological developments throughout the region.

“Freshwater species are incredibly important to livelihoods and economies in the Indo-Burma region,” said Robert Mather, Head of IUCN Southeast Asia. “There are more than 1,780 known freshwater fish species in this one hotspot with the majority of threatened species found along the mainstream Mekong River and the central and southerly parts of the Chao Phraya River. Globally, this exceptionally high level of fish diversity is only surpassed by the Amazon and Congo river systems, and it supports the world’s largest inland capture fishery.”

With regard to freshwater fish and their obvious benefits to people it is critical that monitoring focuses on the diversity of species and not only on the biomass and productivity of fisheries as is the current practice in most cases. The currency for measuring fish biodiversity is species, not kilograms, dollars, or catch per unit of effort. Without this change in approach, many species, in particular those of limited commercial importance are likely to decline or disappear unnoticed.

Hydrological developments such as the construction of dams and river clearance for navigation are the greatest immediate cause of concern, but pollution, exploitation and habitat loss also threaten freshwater species across the region. Hydrological modifications are most often incompatible with species conservation in inland waters and may lead to significant increases in the number of species assessed as threatened - a number of which are likely to go extinct. For example, freshwater molluscs such as Lacunopsis globosa are highly specific in their habitat requirements, being almost entirely dependent upon river rapids for their survival.
“If current plans for the construction of hydroelectric dams proceed as proposed, over the next decade the proportion of fish species threatened by dams is predicted to increase from 19% to 28% and the proportion of mollusc species impacted by dams is likely to increase from 24% to 39%,” said William Darwall of the IUCN Global Species Programme. “There is still time for the information in this IUCN report to help large scale developments - particularly in the energy and water sectors - to proceed in a sustainable way with reduced impact on freshwater species and the dependent livelihoods.”

The majority of current protected areas in the Indo-Burma region have been developed according to the conservation needs of terrestrial habitats and species, but this report highlights the need for conservation areas specifically targeting freshwater species and identifies potential sites for their protection at the catchment scale.

Issues involving freshwater species and conservation will be discussed at the IUCN World Conservation Congress in Jeju, Republic of Korea, from 6 to 15 September 2012.

For more information please contact:

Dararat Weerapong, Senior Communications Officer, IUCN Asia, m +66 89517 8543, e
Camellia Williams, IUCN Species Programme Communications, IUCN, t +41 22 999 0154, e

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