"The East Kolkata Wetlands' "bheris" — shallow fish…" — Rajashree Ghosh (#c406)

Card #c406IR // #c406SynthesisThesis

The East Kolkata Wetlands' "bheris" — shallow fish ponds fed by treated urban wastewater — are a century-old, Ramsar-recognized circular system that converts municipal sewage into protein; a six-month multi-site assessment found a notable improvement in the Water Quality Index across several sites and a significant reduction in faecal coliform counts, indicating growing suitability for sustainable aquaculture.

— In our words · Source: Water Quality and Faecal Coliform Dynamics in Aquaculture Bheris of East Calcutta Wetland (Rajashree Ghosh)

[Use when]

The most durable circular economies aren't new tech — Kolkata has been turning sewage into protein for a century; measure the system before assuming it's failing.

[Why it matters]

One of the world's oldest large-scale circular-economy food systems — a city farming fish in its own treated wastewater — and the measured trend is improving water quality, not declining.