Frogs* are excellent indicators of the health of an environment as they are susceptible to small amounts of poisons entering the environment. If these poisons are minimal frogs are still effected which can be seen by limb deformities – large amounts kills the frogs which indicates a ‘big’ problem.
Studies have produced theories as to the causes of limb deformities which include a parasite known as the trematode. Herbicide used on farm lands to kill weeds is entering the waterways which are killing off aquatic plants. The death of aquatic plants leads to a reduced oxygen level. This herbicide run-off is also toxic to tadpoles and other aquatic life. In one of the studies it was found that this herbicide was impacting on oxygen producing aquatic plants resulting in an increased frequency of severe trematode infections in the kidneys of tadpoles. Storm water runoff from tar roads is also a major problem as it takes with it carcinogens from spilled fuel which are known as some of the most dangerous cancer causing pollutants to man. These pollutants must affect aquatic life.
The loss of frogs in any ecosystem is disturbing as frogs are needed to control insect pests and are needed for the balance of nature to exist.
* Frogs refer to both frogs and toads in this post.
Guide at African Insight