Which ocean process exposes the coastal aquatic organisms to land-based predators?

The correct answer is - Tidal patterns.

The aquatic organisms that live very near the coast are becoming exposed to land and air predators in certain parts of the day, and the reason for that are the tidal patterns. The tidal patterns are simple, in certain part of the day the water comes more towards the land, while in other parts of the day it retreats back towards the sea/ocean. The problem for the aquatic organisms comes when the water is retreating, as they have brought more inland previously, and than they end up trapped on the land or in small pools of water. That situation makes them a very easy pray for the land and air animals, which over time had learned the tidal patterns and patiently wait for the retreat of the water and have a nice aquatic meal.

not sure if this is what you'r looking for eubacteria and archaebacteria