As suggested by the name, the Great Lakes are all lakes - bodies of fresh water.
Seas are bodies of salt water.
Because they are fresh water lakes. If they were salt water, they would be called seas.
There is no "5 great seas" but there is 5 great lakes
Freshwater Seas The Great Lakes - 2009 TV was released on: USA: 22 December 2009
There are no seas around the State of Michigan. Michigan has coasts on four of the five Great Lakes - Lakes Erie, Huron, Michigan and Superior
Some inland seas include the Caspian Sea and the Great Lakes.
yes there are salty seas. but lakes are very rare to find salty.
Salts dissolved from the mountains are transported in lakes or seas by rivers.
The Great Lakes
Other seas, animals, plants, other lakes, snow, ice
lakes and rivers
Seas are salt water body made of sediments, and lakes are entirely of fresh water no salt at all.
Because they are fresh water lakes. If they were salt water, they would be called seas.