... In general, a sea is defined as a portion of the ocean that is partly surrounded by land. Given that definition, there are about 50 seas around the world. But that number includes water bodies not always thought of as seas, such as the Gulf of Mexico and the Hudson Bay.
Moreover, in some cases, a sea is completely landlocked. The Caspian Sea is the most famous example, though this sea, which lies between Russia and Iran, is also referred to as the world’s largest lake. Other seas surrounded by land include the Aral Sea and the Dead Sea. They contain saltwater and have been called seas for many years, but many oceanographers and geographers are more inclined to call them lakes.
Still, that leaves dozens of water bodies that fit the traditional definition of a sea, even though they can be quite different from one another. A sea can be more than 2.6 million square kilometers (1 million square miles) in area, such as the Caribbean Sea. Or, it can be as tiny as the Sea of Marmara, which is less than 12,950 square kilometers (5,000 square miles) in area. This tiny Turkish sea connects the Aegean Sea and the Black Sea. ...
