Mosquitoes multiply as frogs die silent death

Guwahati: A study and assessment by conservation advocacy group has revealed that more than half of the 20 species of frog found in and around the capital city of Guwahati in Assam have gone extinct, which is adversely impacting the ecological balance that keeps a natural check on mosquitoes and vector borne diseases.

Pointing out that the creature plays a vital role in controlling insects and mosquito populations, conservation advocacy group Help Earth has found that frogs have stopped croaking with the urban expansion in the city of 1.4 million.

Conservationist who released their findings on April 28 — Save the Frog Day — said that the amphibians are facing a silent death.

Noted herpetologists and general secretary of Help Earth, Jayaditya Purkayastha, said, “The assessment was done during last six years. In fact the work is still on. What we could gather from different ecological parameters vis-a-vis urban expansion is that except five to six frog species, the rest will be locally wiped out from Guwahati 10 years down the line. The five to six frog species will survive because of their adaptability in the urban situation.”

Experts pointed out that amphibians are one of the prime components for the well-being of an ecosystem. As amphibians need both land and water to complete their life cycle, pollution directly affects them.

 “In the urban context, since we have filled almost all the water bodies, and tarred up the roads, frogs have no place to lay eggs and are fast vanishing. Such is the case with our city Guwahati too. Though, the city is home to at least 20 species of frogs, we hardly hear them crock now,” said Mr Purkayastha.

He said that one of the vital ecosystem services provided by frogs are controlling insects and mosquito populations.

“They also eat  the larvae of mosquitoes, thus helping in checking the rise of dengue and malaria. In their absence, the ecosystem will collapse,” he added.

In the 1980s, unabated export of frogs from India led to serious impact on agriculture, forcing the central government to impose ban on the trade. As frogs prey on insects, they are also natural controller of pests in agricultural fields.

Urbanisation is not the only threat to these cold-blooded vocalists, as in the neighbouring state of Sikkim, the conservationists have discovered that massive hunting of frogs is posing a serious threat to their survival.  

“Hunting of frogs is done for two reasons mainly — meat and medicine. They use frogs to cure many ailments which are not validated scientifically,” said  Basundhara Chettri, assistant professor, department of zoology, Sikkim Government College.

“Based on surveys in different places in Sikkim, we observed that local people collect amphibians from various streams, during monsoon season (June-September) from dusk to early night hours. This also overlaps with the breeding season of the frogs,” Mr Chettri said while discussing the issue at a “Biodiverse” conference organised at IIT-Guwahati recently.

“There is no commercial exploitation of frog in Sikkim. People extract frogs for their own consumption. The collection is used as meat supplement as well as for some medicinal purposes after smoke drying. But the medicinal role is not scientifically validated,” Mr Chettri asserted.

Hunting in the neighbouring state is also impacting frog population in Assam.