For instance, if a fisher in Taiwan discovers that a certain species of fish he/she frequently catches is becoming rarer and rarer, there might be a substantial issue in the water that fisher is fishing in. It could be that there is a new predator in the water that has changed the animal food chain, a source of pollution, or perhaps even a larger problem. Regardless of the reason, this process of observing animals can help identify potential issues before they become severe problems in the world.