Ears

Mercury pollution is a global threat to human health, especially to unborn babies and young children. Exposure to methylmercury, a type that forms when mercury washes into lakes and streams, can harm children’s brain development and cause symptoms including speech impairment and muscle weakness in adults who consume seafood as their main food source. Methylmercury also threatens health and reproduction in fish and other wildlife. Humans, animals and birds are exposed to methylmercury when they eat fish and shellfish. Scientists have been working for decades to understand how and when fish accumulate mercury. This information is key for assessing mercury risks across different water bodies and landscapes, and for evaluating policy changes designed to reduce mercury emissions. For decades, scientists have used fish ear stones, known as otoliths, to gain insights into fish growth, migration, diet and the timing of their exposure to certain pollutants. These tiny structures of...