How do people attempt to modify littoral drift? What strategies do they use? What are the positive and negative impacts of these actions? Why are the coastal wetlands poleward of 30° N and S latitude...

How do people attempt to modify littoral drift? What strategies do they use? What are the positive and negative impacts of these actions?

Why are the coastal wetlands poleward of 30° N and S latitude different from those that are equatorward? Describe the differences.