Question

1. what do we
2. if the average salinity of the ocean is not changing, what must be true about the rates of addition and removal of minerals from seawater?

Explanation:

For the average salinity of the ocean to remain constant, the total amount of minerals in the ocean cannot change over time. This requires that the rate at which minerals are added (e.g., from river runoff, hydrothermal vents) is balanced exactly by the rate at which minerals are removed (e.g., via sedimentation, biological uptake, chemical precipitation).

Answer:

The rates of mineral addition to seawater and mineral removal from seawater must be equal (in equilibrium).