Final answer:
Nitrates from the ocean floor can be returned to the ocean surface through upwelling, a process where cold, nutrient-rich waters rise from the deep ocean. This provides essential nutrients such as nitrates to marine plants and animals.
Step-by-step explanation:
Nitrates from the ocean floor can be returned to the ocean surface through a process called upwelling. Upwelling occurs when cold, nutrient-rich water from the deep ocean rises to the surface, bringing nitrates and other essential nutrients with it. This typically happens along coastlines where wind or currents push surface waters away from the shore, allowing deep, nutrient-rich waters to replace them. The nitrates can then be utilized by marine plants (phytoplankton) and animals (zooplankton), which in turn can be consumed by larger organisms.
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