Industrial fishing means more risky mercury for humans says new study The research demonstrates the intricate connection between global seafood markets, chemistry, and biology, explaining why sustainable fishing is so critically important.

The Methylmercury Menace
Methylmercury, which is noxious to the nervous system and dangerous to human health, especially for children and fetuses. It can act as a neurotoxicant and has been associated with developmental delays, and impaired cardiovascular function.
Specifically, the study found that industrial fishing in tropical and subtropical regions is the biggest culprit — accounting for more than 70% of all methylmercury fished from the ocean. What underlies this growing problem is that these waters harbor the ideal thermodynamic conditions for converting mercury into methylmercury, a form of organic mercury, through microbial processes; these high-trophic predator fish (like many targeted by industrial fisheries) are typically found at the top of marine trophic-chain where bioaccumulation rates of methylmercury already tend to be dramatically elevated.
Challenges With Global Demand For Seafood
Large pelagic seafood like tuna has been rapidly increasing in popularity due to the advancement of industrial fishing techniques. The use of onboard freezing and fish aggregating devices has dramatically expanded tropical and subtropical tuna fisheries, resulting in a wider distribution of these formerly exotic fish across the global marketplace.
But this easy availability comes at a cost. Methylmercury accumulates in large pelagic fish, e.g., tuna, to a higher degree than in smaller, less living duck species. This makes the seafood that many more people are eating on a regular basis… the very same food most likely to be contaminated with a potent neurotoxin.
Conclusion
These findings, coupled with urgent calls for more sustainable and environmentally responsible seafood production reflect global awareness of marine biodiversity loss. This means a shift in harvesting efforts to smaller, less methylmercury-laden species would minimize the risk of additional methylmercury exposure while maintaining seafood as a healthy and crucial part of diet worldwide. That will require cooperation among regulators, industry and the food we eat, to tighten pollution controls and make more educated choices about which seafoods we choose to eat.