Dead Zones
- When there are less levels of oxygen
- Can occur naturally
- Runoff can cause a dead zone
- The second largest dead zone is the Gulf of Mexico
Waste Disposal
- When humans dump harmful toxins into the ocean
- Kills of many marine organisms
- More than half of the ocean waste is in the Baltic Sea
Over Fishing
- When humans fish to much and the fish die out.
- Caused by humans
- More and more fish are being over fished
- Predators will die out
- The Mediteranian is almost out of fish
Artificial Reefs
- Man-made reefs
- Usually old and broken ships
- Affects ocean organisms and humans like fishermen and scuba divers
- Popular place for fish
Climate Change
- Not just randomly made, takes time
- Warmer climates cause ice caps to melt, therefore flooding the oceans.
- Warmer water will kill off algae, the biggest producer of oxygen
Oil Spills
- A spill of oil(duh)
- Oil spills are always caused by humans
- Affects any organisms close enough to the spill
- Runoff is a cause of oil spills
- Food and money is affected