Once in a while, the propellers hit a large chunk of ice floe. Then you hear and feel a distinct shudder. When the ship is in heavy ice floes like this, it almost seems as if I could run along beside it, or at least ski. There are very few cracks I could not jump across. I'd have to stay away from the ship, though, because it breaks and overturns floes as it goes.
Planktonic animals float and move around with the water.
The populations mix and a few dominant types survive. Benthic forams probably cannot travel more than a few centimeters in their lifetimes, so populations become localized. Also, the environment of benthic forams, nutrients and oxygen, for example, vary widely over short distances. Planktonic forams live in an environment that is usually the same for hundreds of kilometers in any direction, and several hundred meters vertically. Since the water they live in is always mixing and moving, they may move many kilometers in their lifetimes.