India's fishery sector loses $2.2 billion annually due to wastewater contamination: Study

New Delhi: India's fishery sector loses over $2 billion due to untreated wastewater contaminating waterways, according to a study published on Wednesday.

It also said the country suffers an annual economic loss of $246 million from diarrhoea caused by contaminated drinking water due to poor wastewater management.

Launched at the World Ocean Summit in Japan by ocean health initiative Back to Blue and the Ocean Sewage Alliance, the study highlights the high cost of inaction in wastewater management in Brazil, India, Kenya, the Philippines and the United Kingdom.

Untreated or poorly treated wastewater is a major source of pollution and disease. When it enters rivers, oceans and drinking water supplies, the consequences are severe.

Among the five countries, India's fishery sector suffers the most, losing 5.4 per cent ($2.2 billion) of its economic value annually, followed by Kenya (5.1 per cent).

Since India is a major seafood supplier, this threatens both domestic food security and export markets.

Also, among the countries studied, India incurs the highest healthcare costs from diarrhoea linked to contaminated drinking water. With a wastewater treatment rate of just 21 per cent, nearly three times as many people are affected, resulting in annual costs of $246 million.

Brazil faces severe agricultural impacts as crops like soybeans are highly sensitive to soil salinity, worsened by irrigation with untreated wastewater.

India experiences lower proportional losses due to lower soil salinity but still suffers the highest absolute revenue loss ($1.2 billion), the study says.

Around 10 per cent of agricultural land in developing countries is irrigated with raw or partially treated wastewater, which often contains toxic heavy metals like zinc, chromium, manganese and iron. While wastewater nutrients such as nitrogen and phosphorus can initially boost crop yields, long-term use leads to soil salinisation and reduced yields.

Amelia Wenger, Conservation Scientist and Water Pollution Programme Lead at the Wildlife Conservation Society, said the cost of inaction is evident in India and beyond. "Investing in adequate sewage and wastewater infrastructure is the only viable solution," she said.

Where large-scale infrastructure is lacking, decentralised wastewater systems can offer practical alternatives and new high-tech innovations are emerging, she added.

Policymakers who look beyond infrastructure investment and focus on circularity can ensure wastewater is repurposed as organic fertiliser, biogas or even a source of renewable energy, Wenger added.

Like much of the developing world, India views wastewater pollution partly through the lens of water scarcity.

Asserting that expanding treatment capacity is key, Nitin Bassi, senior programme lead for sustainable water at the Council on Energy, Environment and Water (CEEW) said, "We need to improve both water quality and the usable quantity of water. If more wastewater can be captured, treated, and reused, it will reduce the pressure on our freshwater resources."