 Various conservation initiatives are being attempted around the world . The Chinese giant salamander , at 1 @.@ 8 m ( 6 ft ) the largest amphibian in the world , is critically endangered , as it is collected for food and for use in traditional Chinese medicine . An environmental education programme is being undertaken to encourage sustainable management of wild populations in the Qinling Mountains and captive breeding programmes have been set up . The hellbender is another large , long @-@ lived species with dwindling numbers and fewer juveniles reaching maturity than previously . Another alarming finding is the increase in abnormalities in up to 90 % of the hellbender population in the Spring River ( Arkansas ) watershed . Habitat loss , silting of streams , pollution and disease have all been implicated in the decline and a captive breeding programme at Saint Louis Zoo has been successfully established . Of the 20 species of minute salamanders ( <unk> spp . ) in Mexico , half are believed to have become extinct and most of the others are critically endangered . Specific reasons for the decline may include climate change , chytridiomycosis , or volcanic activity , but the main threat is habitat destruction as logging , agricultural activities , and human settlement reduce their often tiny , fragmented ranges . Survey work is being undertaken to assess the status of these salamanders , and to better understand the factors involved in their population declines , with a view to taking action . 
