Wetland, Housing and Bird Survey
A panchayat in Kuttanad proposes to fill a 2-hectare seasonal wetland to build a housing colony for 40 families. Before clearance, a school biodiversity club surveys the site for three weeks. They record 18 species of water birds, 6 species of frogs, 4 species of fish, and dense reeds used by nesting birds. Nearby paddy fields depend on the wetland for irrigation and flood storage. During the survey, the club also finds plastic waste and an invasive African catfish in a connected pond. At the panchayat meeting, one member says the wetland is 'waste land' because it is waterlogged for six months and cannot be built on. Another says the housing is needed and the birds can 'move somewhere else'. The students are asked to present evidence-based recommendations, not emotions.
1. Evaluate the 'waste land' claim using the survey data and ecosystem services.
Read the worked answer
- The wetland is not waste land. The survey records 18 water-bird species, 6 frog species, 4 fish species and nesting reed beds, showing that it supports a food web and breeding habitat.
- Seasonal waterlogging is a function, not a defect. The wetland stores floodwater, recharges groundwater, supplies irrigation water to nearby paddy fields, and supports fisheries.
- Filling 2 hectares would destroy this habitat, reduce flood storage, and increase flood risk for the housing colony and nearby fields. It could also worsen water quality because the wetland currently traps silt and waste.
- The claim ignores these services. 'Cannot be built on' is true, but that is exactly why it should not be built on.
2. Why is 'the birds can move somewhere else' a weak argument? Use habitat requirements and fragmentation.
Read the worked answer
- Birds are not interchangeable. Water birds need specific water depth, food, nesting reeds and undisturbed areas. Nearby wetlands may already be occupied or may not have the same conditions.
- Displaced birds face competition, higher predation and lower breeding success. Frogs and fish are even less able to move to a new site.
- Breaking the wetland into small patches fragments populations and reduces gene flow. Some species may disappear locally even if a few birds are seen elsewhere.
- Moving a few individuals is not the same as conserving a functioning habitat. The argument treats habitat loss as a temporary inconvenience rather than a permanent change.
3. Propose a balanced plan for the panchayat and give one indicator the students could monitor.
Read the worked answer
- Avoid filling the core wetland. Build housing on already degraded or non-wetland land nearby, and keep a buffer zone around the remaining water and reeds.
- Plan drainage so that runoff does not enter the wetland untreated, and provide solid-waste collection to deal with the plastic found.
- Control the invasive African catfish with expert advice, and protect nesting reed beds during the breeding season.
- Involve the families and students in monitoring. One useful indicator is the number of water-bird species and nesting pairs counted at fixed intervals, along with water level and frog calls. A falling trend would show that the plan is not protecting the habitat.