Amphibians are vertebrates whose life cycles are inextricably tied to water; all amphibians have an aquatic or semi-aquatic stage in their development. Amphibian eggs are unshelled which allows for gas exchange and the postential for diffusion of harmful compounds. The most common compounds that negatively impact amphibian popultions are organic chemicals used in pesticides, such as organo-chlorides like DDT. Other, less obvious chemicals include EDCs (Enodcrine Disrupting Compounds), which are chemicals that mimic those the body makes and uses to regulate its processes. EDCs and other chemical contaniments in water can increase developmental abnormalities, sexual disfunction or sterility, and death in amphibia.
Temperature and light are also important factors in amphibian population health. Increases in temperature and UV exposure have been linked to physical abnormalities and population decreases in amphibia.
Fungal and Viral infections pose servere threats to native frog popultions, and have been implicated in mass die-offs in Australia and South America.
The most preventable threat towards amphibian populations is habitat destruction. Amphibians thrive in moist enviroments, such as old growth forests, marshlands and near vernal pools. Development of essential breeding grounds is a leading cause in population decreases, which is why protected land like GEWA are bastions of amphibian biodiversity.