Simply because of their size - the word "sea" implies a very large body of water.
Sometimes. Especially when it is stormy , and after the Spring melt when all the inland waters are at their highest. Lakes as large as the Great Lakes can also be subject to tides and riptides.
Lake Urmia
A large inland body of water is called a lake.
Yes, bald eagles are to be found there, near the coast and large inland lakes.
aral
a lake
a lake
The Canadian Prairies
Hudson bay
A large inland body of water is called a lake.
A large inland body of water is called a lake.
Shoreline areas are commonly defined as the interface or transition areas between land and sea, including large inland lakes.