1. Ocean Systems: Human Dependence and Modification

2. Human Dependence and Modification 2 Major Systems: Ocean currents Ocean food webs

3. Turn and Talk to Your Neighbor 1.How do Ocean Currents effect humans? 2.How do we depend on Ocean Food Webs?

4. Human Dependence We depend on the ocean for: 1.Weather The oceans absorb a lot of energy from the sun. The warmer the water the more evaporation happens. The more evaporation that happens, the more rain there will be. The cooler the water the less evaporation happens. The less evaporation the less rain falls.

5. Human Dependence We depend on the ocean for: 2.Food Seafood provides a lot of world’s protein. (Fish, Shrimp, Oysters, Crabs) (1/6 of the worlds population depends on the ocean as their primary source of protein.) 3.Transportation most of the worlds goods are transported by ship across oceans. 4.Recreation Many countries main source of income is through ocean tourism: (Beach resorts, sport fishing, scuba diving, boating.)

7. 1.Over-fishing Disrupts the food web which may cause organisms to migrate to other areas Human Modification

8. Suppose all the TUNA were removed from the food web below: How would this effect the other organisms in the food web? How would it effect humans?

9. Human Modification 2. Artificial Reefs human-made underwater structure, typically built for the purpose of promoting/preserving marine life Texas Clipper – (9 min )

10. Human Modification 3.Run Off and Pollution Excess amounts of Phosphorus/Nitrogen enter rivers and streams in runoff from farming and factory waste. Phosphorus and nitrogen happen to be the main food source of many types of algae.

11. Harmful Algal Blooms “Red Tides” Red Tides Video Clip HABs (Harmful algal blooms a.k.a. Red Tides) possibly result from this excess phosphorus/nitrogen being dumped into the ocean. Some HABs occur seasonally and naturally, while others appear to be linked to runoff/pollution.

12. Turn and Talk What can we do to help prevent HABs from happening? Is it possible to completely stop them from happening? Why or why not?