"Shellfish are the prime cause of the decline of morals and the adaption of an extravagant lifestyle. Indeed of the whole realm of Nature the sea is in many ways the most harmful to the stomach, with its great variety of dishes and tasty fish."
-Pliny the Elder, ~50 AD
Out of one body of water and into another. A Seafood Chef learns recipes for both fish and shellfish alike.
Also increases the number of Oysters you can see naturally spawning on the map.