Sardines are named after Sardinia, the Italian island where large schools of these fish were once found. While sardines are delightful enjoyed fresh, they are most commonly found canned, since they are so perishable. With growing concern over the health of the seas, people are turning to sardines since they are at the bottom of the aquatic food chain, feeding solely on plankton, and therefore do not concentrate heavy metals, such as mercury, and contaminants as do some other fish.