Sea turtles are exposed to, and accumulate, contaminants such as trace elements and organic chemicals (e.g. industrial chemicals, pesticides, pharmaceuticals) that can have negative implications for health. These contaminants enter the environment through a variety of urban, agricultural and industrial sources, which means that chemical exposure can change over time. However, the majority of toxicological studies only include one timepoint, which provides only a snapshot of chemical exposure. A long-term monitoring project carried out in Port Curtis, one of Australia’s largest shipping ports, has offered the unique opportunity for temporal analysis of contaminants in the green turtle population foraging within the port. Since 2016, trace elements have been assessed using chemical analysis and organic contaminants have been assessed using species-specific cell-based techniques. Cell-based techniques can be used to assess the effects of environmentally relevant mixtures and concentrations of organic contaminants to which turtles are exposed by extracting contaminants from turtle blood and testing the toxicity of extracts on sea turtle cells. Trace elements and organic contaminants have demonstrated significant temporal changes, highlighting the importance of including temporal aspects in toxicology studies to better identify exposure baselines, and changes to exposure that have the potential to impact turtle health.