Gibbs himself considered the following problem that arises if the ideal gas entropy is not extensive. Two identical containers of an ideal gas sit side-by-side. There is a certain amount of entropy S associated with each container of gas, and this depends on the volume of each container.
The intertidal zone is the area of the ocean between the high tide and low tide lines, usually on the beach at the water's edge. If you think of the line created at high tide as the upper limit and the line created at low tide as the lower limit, the intertidal zone is everything between those lines.
The pelagic zone refers to the open ocean, away from the shore. Depending on depth, the pelagic zone varies widely in amount of sunlight, temperature, and pressure. This ocean habitat is home to a vast array of marine organisms including plankton, large and small migratory fish, marine mammals and reptiles.