Mercury is a persistent, toxic pollutant that impairs organismal behavior, health, and reproduction in many ecosystems across the world. Released into the environment via anthropogenic activity as inorganic mercury, this contaminant undergoes deposition and transport across the landscape, where it is later transformed into its more bioavailable and toxic form, methylmercury. While exposed wildlife often bioaccumulate methylmercury from their diet, offspring can be exposed during development from maternal transfer. This exposure during sensitive stages of development can result in embryotoxic effects regarding embryo mortality and development, as well as differential physiology for survived offspring. While great attention has been casted upon methylmercury, there remains a crucial need for more extensive research into the exposure and bioaccumulative properties within wildlife, and how such exposure in adults can also impair offspring. Waterfowl are of particular concern given their function within wetland ecosystems, and their propensity to bioaccumulate contaminants. To address these knowledge gaps, my PhD dissertation sought to conduct a broad assessment of exposure and bioaccumulation in wild waterfowl, and to investigate the impacts of developmental exposure on embryo development and hatchling physiology, growth, and survival. I found that naïve waterfowl released into an environment with legacy contamination readily bioaccumulate mercury at different rates provided their foraging strategies and associated microhabitat selection. Additionally, by surveying wild wood ducks (Aix sponsa) across natural wetlands, I determined that temporal trends in mercury exposure exist during the reproductive cycle that may influence offspring produced later within the egg-laying season. By experimentally dosing eggs containing viable embryos with methylmercury, I found this toxicant to influence both the survival and developmental growth in mallard duck (Anas platyrhynchos) embryos. Furthermore, I found the same for hatched wood duck ducklings exposed during development, with exposed ducklings growing slower and having reduced survival in both captive and wild conditions. Combined, this comprehensive examination of mercury bioaccumulation and developmental impairment in waterfowl can be used to advocate for the better environmental stewardship regarding pollution and can be used to develop crucial management strategies for alleviating the negative impacts of mercury exposure in organisms within their environment.