A longshoreman stands in front of a large pile of oyster shells on waterfront pier in Atlantic City in 1910. Back then, oysters were incredibly abundant. In the late 1800s, fishermen pulled in 10 million bushels of oysters each year but, by the mid-1900s, the catch had dropped to 1 or 2 million bushels each year because of disease and overharvesting.

Nowadays, the normal catch is down to 100,000 bushels or even less. But because of the phenomenon of shifting baselines—a phrase describing the fact that our standard for what "normal" means changes with experience and time—most people think that a haul of 100,000 bushels of oysters is a good catch!