Environmental pollution is one of the greatest threats to biodiversity world-wide and is suspected to contribute to global amphibian declines. This concern has prompted extensive experimental investigation of contaminant effects in a variety of amphibian taxa. Most early studies evaluated acute effects on amphibian embryos and larvae under controlled laboratory conditions, but recent studies have broadened the focus of amphibian ecotoxicology to include other ecologically relevant endpoints (e.g., sublethal effects) and have used mesocosms or artificial ponds to increase ecological realism. These studies have demonstrated that contaminants can have a broad array of adverse effects on larval amphibians, and these effects may interact with a variety of biotic (e.g., presences of predators, conspecific or heterospecific competitors) and abiotic (e.g., hydroperiod, temperature) factors. However, the links between individual-level effects observed in experiments and amphibian population dynamics have seldom been explicitly explored, complicating our ability to effectively conserve amphibian populations or species. We use our research on the effects of mercury (Hg) on toads as a model for bridging the gap between individual-level effects of environmental contaminants and amphibian population dynamics.