Final answer:
The correct statement is that waves can erode, deposit, or simply transport sediment, shaping the coastline. Wave height increases as they approach shallow water due to shoaling, and storm winds can generate large waves, while tidal forces have a smaller effect.
Step-by-step explanation:
The true statement about how coasts are affected from the water side is that waves can erode, deposit, or simply transport sediment. Waves have a significant impact on coastlines as they approach the shore. Due to a process known as shoaling, where the water depth decreases, the energy of the wave is compressed into a smaller volume, creating higher waves.
Moreover, the orientation of the coastline and its exposure to open water can protect it from wave action to some extent. Ocean waves are primarily generated not by earthquakes, but by interactions between the wind and the surface of the water. Strong winds transfer more energy to the waves, and intense storms can create massive waves that affect shorelines far from the storm's origin. Tides, influenced by the Moon's gravitational pull, also contribute to wave formation, albeit to a lesser extent.
It's also crucial to note that human activities like dredging can exacerbate coastal erosion and cause harm to marine ecosystems. When considering river interactions with coastlines, rivers carrying high silt content that flow into areas with minimal wave action will tend to create deltas, whereas those with low silt or in areas with significant wave action create estuarine environments.