Indicator Species - GCSE Biology Definition

An indicator species is a type of organism whose presence, absence, or abundance in an environment can tell us about the health of that ecosystem. These species are sensitive to changes in their surroundings, such as pollution or climate change, making them useful for scientists to monitor environmental conditions. For example, if there are fewer of certain indicator species, it might suggest that the ecosystem is being damaged or is changing. By studying these organisms, scientists can gain valuable information about the state of the environment and take steps to protect it. Common examples of indicator species include frogs, which are sensitive to water quality, and lichens, which can indicate air pollution levels.