Bhutan’s wetlands and river systems are one of the most important habitats in the world for the critically endangered white-bellied heron and the vulnerable black-necked crane.
This is because every winter, about 600 black-necked cranes visit the country and 25 white-bellied heron out of 60 individuals in the world are found to be living in the country, according to records with the Royal Society for Protection of Nature (RSPN).
Wetlands are areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres.
Bhutan is estimated to have more than 3,500 high altitude natural wetlands, which is a source of various ecosystem services in the country and the region.
Deputy Chief Project officer at RSPN, Jigme Tshering said, “Wetlands are important aspect of a natural environment. It provides provisioning, cultural and, regulating services such as climate regulation, carbon sequestration, and flood protection.”
“Wetlands are referred to as kidneys or biological supermarkets of the landscape as they purify polluted water and provide volumes of food for plants, animals, and humans,” he added.
The omnivorous black-necked cranes feed on seeds, tubers, fish, vertebrates and invertebrates in the wetlands and agricultural fields.
Despite natural threats from global warming, Jigme Tshering said the critical habitats are located among human settlements, which posed man-made threats to vulnerable species through land fragmentation, encroachment and unplanned developments in the country.
The shy and elusive species, white-bellied heron, which lives along few rivers of Bhutan is also under threat from developmental activities along the river basins.
Although there were records of 80 juvenile white-bellied herons in the last 17 years, there were no nesting records of the species in any parts of the world. In recent years, extraction of river materials along Punatsangchhu is said to have disturbed the habitats, thus displacing the species from its original place.
Research officer with RSPN, Indra Acharja said, “We live by the river and are dependent on our rivers for socio-economic and ecological reasons but the rivers are important for species survival.”
Conservation initiatives were put in place to create a safe gene pool of the species through, educating people, monitoring, captive breeding and rearing. “But we are losing track of the herons living in large rivers.”
Each year, numbers of juveniles were found dead, which according to Indra Acharja could be due to loss of wetlands, decreasing fish population, small breeding population, and stunted population growth in general.
The World Wildlife Fund and Ugyen Wangchuck Institute for Conservation and Environmental Research carried an inventory of high altitude wetlands in the country. The latest inventory was done in 2016 but was not published.
The study found that major threats to wetlands arise from unplanned and unregulated tourism, grazing pressure, loss of wetland ecosystem integrity, lack of awareness among stakeholders, emerging threats of climate change and lack of coordination among various developmental agencies.
In an effort to save wetland and water dependent species, RSPN’s conservation programmes engaged local communities and international stakeholders to take ownership of the species.
About 52 percent of total wetlands are found in Drangmechhu basin, primarily contributed by Mangdechhu and Chamkharchhu river systems.
Jigme Tshering and Indra Acharja covered “Water habitats: wetlands and riverine systems” in the recently concluded literary festival, Mountain Echoes.