American Eel
American eel is often served in sushi. It contains high levels of PCBs (harmful chemicals) and mercury (heavy metal), which may negatively affect certain functions of the body. An eel, also known as unagi on various sushi menus, is a type of fish that grows slowly. It is at a high risk of collapse because it is usually overfished. Since it has a high risk of going extinct, various Asian countries usually go in search of the fish. They play a significant role in preserving water life. For example, eels help spread the mussel populations who work as natural filters of water. Eels are also known to help store and absorb contaminants such as endocrine disruptors such as PCBs and retardants. This is why they can easily be contaminated and adults are advised to consume only one eel in a year.