Link to teaching case:
Rice farming and raising mallard ducks are important livelihoods in the Philippines, and both are seriously affected by the presence of the golden snail. In lake areas, where mallard ducks are farmed, the disappearance of this indigenous snail due to pollution and dredging is a problem as the snails are an important food source for the ducks. Where snail populations have been depleted, farmers must rely on expensive commercial feed. On the other hand, where rice cultivation is the main livelihood, golden snail infestations can destroy of up to 60 percent of a crop. Rice farmers rely on chemical inputs like molluscicide, fertilizer, insecticide and herbicide - resulting in environmental degradation and significantly increasing the cost of production.