How does water pollution effect a bullfrogs life?

Impacts on Bullfrogs (or any aquatic life) can be described i several categories:

Toxic:

Toxic effects are the impact of poisons on life forms. With water pollution these impacts can be realized in two distinct ways, by direct eating or adsorption of the toxin through the mouth or skin, and secondly by the ingesting of food which has accumulated poisons. This second type of intake is significant as Bullfrogs are predators (although not top preditors) and can be nearer the top of a bioaccumulation chain that starts with microscopic animals eating toxins on the stream or swamp bottom.

Mutagenic:

Mutagenic effects does not mean frogs changing into monster frogs like in an old Scifi movie. It means that the frogs develop changes at the cellular level that decrease their life spans, affect their success at breeding, cause cancers, cause deformity in the offspring or similar. These impacts are generally caused by complex organics (PAH etc) in the water or waste pharmaceuticals from sanitary sewerage reaching the water

Ecosystem related:

The impacts on the frogs can result from impacts on the ecosystem. The changes and pollution can reduce the frogs prey animals, breeding spots, hiding spots, water pH and water temperature. In addition if the pollution has impacted the normal prey of other predators they may switch to Bullfrogs as an alternative food source