The population of these animals have decreased a lot since people began littering and polluting their habitats. Pollution in wetlands areas is believed to be the cause of some genetic changes in frogs in some areas.
People pollute the wetlands with pesticides and road run-off such as oil and gasoline.
The construction of new homes and roads leads to the drainage and filling in of wetlands. Changes in the ozone layer have also had an effect on wetlands. There are many things that can be done to help protect wetlands and bullfrogs. People need to make sure that local governments are aware of the problems that can occur when too many houses are built. Wetlands must be protected by law.