Environment that we live not forever be in stable condition and balanced. Some human activities have changed the environment function properly. Some animals and plants has its own sensitivity to environmental changes. Decrease in species diversity or a decrease in population has become an indicator of environmental pollution.
Animals as environmental indicators The existence of several animals had been long been used as indicators of environmental pollution. Frog is one of the animals that have a sensitivity to environmental changes. Decline in populations of frogs in our environment can be an indication that the neighborhood has undergone a change that causes the frog habitat disturbed.
Other animals are eels. Use of pesticides by farmers had already made in the rice field eel population decline. Though eels are a food source that contains high protein. But because the eel has a sensitivity to the environment is polluted, the population eventually decline as exposure to pollution in the environment field. Planaria, animal phylum that includes a type of flatworm Flatworm also turned out to be an indication that the condition of waters polluted or not. Planaria population decline in the waters become an indicator that the environment has been polluted waters.
In addition to population decline that could be used as indicators of environmental pollution was increasing population can be used as clues to environmental changes. Rat explosion which has reduced production of rice farmers were allegedly due to an imbalance in the environment. The loss of one component of the ecosystem is a snake that many people arrested turned out to have made the rat population increases and the impact on food production. The presence of red Tubifex worms are often used as fishing bait can also be used as an indication of organic waste pollution.
Plants as environmental indicators Apart from animals, plants also turned out to be a clue the presence or absence of pollution in a region. Lichenes population similar lichens that are the result of symbiosis between algae and fungi is an indicator that the environment has been polluted. Its existence can we observe in the trees, rocks or walls that are often exposed to rain. So by looking at the population we can determine the amount of light or heavy levels of environmental pollution in a region.