Many environmental contaminants biomagnify in marine food webs, reaching high concentrations in top predators, posing health risks to humans and wildlife. Biomagnification is highly affected by dietary preferences of different species and locations of food foraging activity. The combination of climate driven changes in ocean conditions and fish harvesting activities by humans is causing major changes in marine food webs that also affect contaminant biomagnification. Using the example of methylmercury, a potent neurotoxin found ubiquitously in most marine environments, this presentation will explain how climate, global emissions and contaminant concentrations in marine food webs are intricately linked. The presentation will also discuss of the effectiveness of mitigation measures aimed at protecting human health such as emissions controls and dietary advisories for different fish species.