Chapter 6

Many cattle pastures have ponds to provide water to the livestock, but often by summer's end, these ponds are covered in a thick green scum and fish in the pond die. What is causing the green scum to form, and what might be causing the fish kills?

Why is it appropriate to say that the water cycle is solar-powered?

Explain the potential ecological consequences if the numbers of calcifiers decline.

In general, which land areas and bodies of water would be part of the watershed for a river?

Where is most life in the ocean found - in shallow near-shore regions or in deeper regions? Explain.

Where does the nitrogen and phosphorus pollution that reaches the Gulf of Mexico come from?

What is an estuary, and why are these regions called the "nurseries of the sea"?

What can happen if too much water is removed by a well in coastal areas?

Why is it incorrect to assume that a stream that looks crystal clear is environmentally sound?

What factors determine the identification of the different ocean zones that are