Post on 02-Jan-2016
Human Dependenceand Modification
2 Major Systems:
•Ocean currents
•Ocean food webs
Turn and Talk to Your Neighbor
1. How do Ocean Currents effect humans?
2. How do we depend on Ocean Food Webs?
Human DependenceWe 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.
Human DependenceWe 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.)
1. Over-fishing
•Disrupts the food web
which may cause organisms to migrate to other areas
Human Modification
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?
Human Modification
2. Artificial Reefs• human-made underwater structure, typically
built for the purpose of promoting/preserving
marine lifeTexas Clipper – (9 min)
Human Modification
3. Run Off and Pollution
Excess amounts ofPhosphorus/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.
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.