Fish that have been captured in nets, such as cod, can become contaminated with mercury which becomes concentrated in particular areas of their bodies, including their eye lenses. Yvette Heimbrand ist unter der Creative Commons Attribution-NoDerivatives Lizenz veröffentlicht. Mercury contamination is an international hazard to human wellbeing, particularly to unborn babies and young kids. Methylmercury, a form created when mercury is deposited in rivers and lakes, can be damaging to the mental development of children and lead to symptoms, like difficulty speaking and muscle instability, in adults that consume seafood as their principal sustenance. Methylmercury can adversely affect the health and reproduction of fish and other wildlife, as well as human, animal and bird life when they consume fish and shellfish. Researchers have been engaged in a quest to comprehend the process and timing of mercury gathering in fish for many years. Using fish ear stones, known as otoliths, for decades, scientists have acquired knowledge about fish life cycles, nutrition, and the span of their contact with toxins. The particulars attained from this method are decisive for figuring out the potential dangers of mercury in varied environments and water sources and assessing structural changes proposed to decrease mercury discharge. These minuscule formations made of calcium carbonate, approximately similar in size to a pea, grow inside of the ears of fish and assists them with their hearing and equilibrium.