Final answer:
A marine ecologist studies ocean interactions such as ocean currents, marine life, precipitation patterns, and coastal erosion.
Step-by-step explanation:
A marine ecologist studies interactions in the ocean, including analyzing ocean currents, studying marine life, investigating precipitation patterns, and examining coastal erosion. These subjects help marine ecologists understand the impact of the ocean on weather and climate. Ocean currents, for example, play a crucial role in distributing heat energy around the Earth and influencing weather patterns. By studying marine life, scientists can also gain insights into the health and stability of marine ecosystems, which can be indicators of climate changes.