1. Flagship species: A flagship species is a species selected to act as an ambassador, icon or symbol for a defined habitat, issue, campaign or environmental cause. By focusing on, and achieving conservation of that species, the status of many other species which share its habitat – or are vulnerable to the same threats - may also be improved.
  2. Indicator species: Indicator species are plants and animals that, by their presence, abundance, or chemical composition, demonstrate some distinctive aspect of the character or quality of the environment. An indicator species has a response to stress or any disturbance that can be measured.  For example, many invertebrate insects such as mayflies or stoneflies are indicator species that can assess the amount of oxygen in rivers, which means they are a useful indicator to control river pollution.