Sewage threatens wetlands in Telangana

Hyderabad: The wetlands in Telangana are in urgent need of the state government’s attention. Degradation of the ecosystem in Hyderabad’s lakes due to pollution is an established fact. However, recent studies by scientists have shown that the lakes located in other districts are not exactly pristine either. As per government data, every district in the state, other than Hyderabad and Ranga Reddy, has at least 3-5 per cent of its geographical area covered in wetlands.

One of the main culprits causing the degradation of wetland ecosystems is the sewerage water that finds its way into the lakes. Also, agricultural run-offs, which release phosphates, entering the water bodies is very harmful. Phosphates are an important nutrient for plant growth and presence of too much phosphate in the water results in excessive growth of plants, mainly algae. When these plants and algae die, their decomposition causes the oxygen level in the water to drop thereby slowly killing the entire ecosystem.

A few scientific journals have said that washing of clothes on the banks of lakes should be avoided as detergents also contain phosphates. A Zoological Survey of India (ZSI) scientist said, “Letting sewage into lakes is common in most of the rural areas. This should be regulated.” Sulphates are another concern in the wetlands. Sulphates also get accumulated in the wetlands due to the use of fertilisers, insecticides and fungicides in agricultural fields which surround most of the water bodies in rural areas. High concentration of sulphates can stimulate the action of sulphur-reducing bacteria, which produce a gas that is toxic to fish. A recent study by ZSI in Pocharam lake in Medak and Wyra lake in Khammam revealed that the maximum value of sulphate was 97mg/l in the former and 43mg/l in the latter. While these figures are not alarming yet, they have sparked concerns as the use of chemicals in the fields is only increasing.

Indiscriminate fishing is another major threat to wetlands. In TS, rules related to fishing — like not allowing fishing during the breeding season and usage of fishing nets with large holes — are not implemented.