What’s Happening to Our Food: Seafood Safety, Contaminants, and Human Health
A UC San Diego magazine feature explores how ocean pollutants and biological threats are affecting marine food webs and human health. Scientists at the Scripps Institution of Oceanography are studying how toxic contaminants like mercury and pervasive parasites move through ecosystems, end up in seafood, and impact consumers — with urgent implications for food safety, fishery sustainability, and public health policy. UC San Diego Today
Mercury in Marine Food Chains
- Mercury, a global pollutant from activities like coal burning, mining, and industrial processes, enters waterways and can be converted by microbes into methylmercury, a highly toxic form that bioaccumulates in fish. UC San Diego Today
- Top predator fishes (e.g., tuna, swordfish, deep-sea lancetfish) often contain elevated methylmercury, posing risks to frequent seafood consumers. Severe exposure has been linked to neurological impacts, including nausea, muscle weakness, and developmental effects in children. UC San Diego Today
- To counter this, researchers engineered Bacteroides thetaiotaomicron bacteria that, in mice, significantly reduced methylmercury levels in tissues and waste, pointing toward potential probiotic therapies for humans in the future. UC San Diego Today
Modeling & Food Web Dynamics
- Schartup and collaborators are modeling how contaminants and nutrients circulate through marine food webs under changing ocean conditions. These models use field data, including from deep-ocean species, to forecast exposure risks and help inform regulators and industry on sustainable seafood choices. UC San Diego Today
Parasites and Freshwater Fish
- Beyond chemical contaminants, Scripps scientists also discovered a high prevalence of non-native trematode parasites in popular freshwater game fish in Southern California. Over 90% of sampled largemouth bass and bluegill carried parasites capable of infecting humans. UC San Diego Today
- These parasites can cause gastrointestinal illness, weight loss, and in rare cases, severe heart or stroke-related outcomes. Proper cooking or freezing of fish typically kills the parasites, but analysis of public cooking videos suggests many consumers are unaware of or not following safe prep steps. UC San Diego Today
Seafood Stewardship & Community Engagement
- The Scripps Center for Oceans and Human Health also emphasizes public outreach, including educational programs such as expert-led classes in a demonstration kitchen. These efforts connect scientists, chefs, fishers, and the public to practical knowledge on sustainable seafood sourcing, preparation, and health risk mitigation. UC San Diego Today
How Ecotox Environmental Services Can Help
Ecotox’s current services align with the key issues highlighted by this research and can support evidence-based seafood safety and ecosystem resilience work:
- Contaminant Monitoring & Analysis
- Measure mercury, persistent organic pollutants, and other contaminants across marine and freshwater food webs, including tissue analysis of fish and shellfish.
- Fate & Transport Modeling
- Model how chemical contaminants move and accumulate from water bodies into marine biota and ultimately into seafood consumed by humans.
- Exposure & Risk Assessment
- Quantify human exposure risks (e.g., via seafood consumption) and develop risk profiles to inform regulators, fishery managers, and public health officials.
- Ecosystem Health Assessments
- Evaluate parasite prevalence and other biological health threats in fish populations; integrate findings with contaminant data for holistic aquatic health analyses.
- Educational & Outreach Support
- Provide data-driven content for community engagement, public risk communication, and stakeholder education on sustainable seafood and food safety.
These services help bridge scientific research with regulatory needs, fisheries policy, and consumer health guidance.