Hydrosphere Contents

4. Oceans

Upwelling occurs from the interaction between the geometry of the coastline and the local wind patterns

Nesting bird colonies provide an important source of guano deposits which are mined for their phosphate content.

Upwelling areas are very important biologically and economically because when the water upwells it brings cold deep water to the surface. This water is rich in nutrients and supports a large amount of phytoplankton productivity. This in turn supports a very rich ocean ecosystem with a great variety and abundance of fish. These fish are in turn eaten by predators, including huge colonies of birds off the west coast of South America. The droppings of these bird colonies have accumulated over thousands of years to form guano deposits which are mined for their phosphate content. Coastal upwelling is also important areas for fisheries. 15% of the world's fish are landed in the upwelling off the coast of Peru from only 0.02% of the world ocean surface.

Why is the eventual upwelling of deep water very important biologically and economically?