1. Human Impact

2. Pollution
The introduction by humans of substances, materials,or heat energy that decreases the quality of the environment.

3. Oil Crude oil or petroleum: used primarily for fuels.
Most widespread pollutant in the ocean.
Biodegradable: broken down by bacteria over time.

4. Sources of Oil Pollution
*Millions of gallons

5. Sources of Oil Pollution
Used engine oil can end up in waterways.
Every year oily road runoff from a city of 5 million could contain as much oil as one large tanker spill.
Every year, bilge cleaning and other ship operations release millions of gallons of oil into navigable waters.

6. Sources of Oil Pollution
Air pollution, mainly from cars and industry, places hundreds of tons of hydrocarbons into the oceans each year.
Some ocean oil "pollution" is natural. Seepage from the ocean bottom and eroding sedimentary rocks releases oil.
The BP Oil Spill in 2010 released over 4.9 Billion barrels of crude oil into the Gulf.
A barrel of oil = 42 gallons of crude. This equals 205,800,000 gallons for the BP spill.

7. Effects on Marine Life
Oil causes harm to wildlife through physical contact, ingestion, inhalation and absorption.
Floating oil can contaminate plankton.
Birds lose the ability to fly and stay warm.
Mammals lose the ability to stay warm.
Both may ingest the oil.

8. Solutions
Booms and skimmers can be used in calm seas to collect the oil.
Physically washing mammals and birds.
Double or triple-hulled tankers.

9. Economical Effects Fish and shellfish become unmarketable.
Size of fish catches decreases.
Tourism decreases.
Cleanup costs lots of money!

10. Sewage Raw sewage: untreated, discharged directly into the water.
Treated sewage: has been partially treated using chlorine to kill bacteria and some viruses.
Only 70% of U.S. population has sewage treatment plants.

11. Effects on Marine Life
Organic matter is decomposed by bacteria resulting in anaerobic (low-oxygen) conditions.
Eutrophication: Large amounts of nutrients over fertilize coastal waters which results in blooms.

12. Thermal Pollution
Seawater is used as a coolant in power plants, oil refineries and other industries.
This water is pumped into the sea where it is considered thermal pollution.

13. Effects on Marine Life
High temperatures adversely effect plants and animals, and decrease the amount of dissolved oxygen (D.O.).
Reef-building corals become bleached.

14. Biomagnification
The sequence of processes in an ecosystem by which higher concentrations of a particular chemical, such as the pesticide DDT, are reached in organisms higher up the food chain, generally through a series of prey-predator relationships.
This happens with heavy metals and synthetic chemicals!

15. Heavy Metals: Mercury
Reaches the ocean through natural and human activities.
Accumulates in the food chain.
Causes birth defects and nervous system damage in humans.

16. Synthetic Chemicals
Pesticides: used to control insects, and have saved millions from disease and starvation.
PCB’s: Poisonous chemicals used to cool machinery, and in manufacturing paints and plastics.
Enter ocean from wind, run-off, rivers and sewage.
Absorbed by plankton.
Non-biodegradable, and accumulate in tissues of organisms.

17. Effects on Marine Life
Become Concentrated in organisms as they move up the food chain.
Marine and land birds could not deposit calcium in their eggshells due to DDT (a pesticide) so the shells broke before development was complete. This nearly caused the extinction of the Brown Pelican in the U.S.

18. Marine Debris

19. Plastics: Solid Waste
Flexible materials that can be molded or shaped into different products.
Plastics are strong and non-biodegradable.

20. Effects on Marine Life
Entanglement in plastic lines, nets traps, and packing materials.
Discarded nets can continue to entrap marine life indefinitely which is called Ghost Fishing.

21. Effects on Marine Life
Ingestion of plastic bags or balloons may block the digestive tract causing death from starvation.
Many species of birds eat small plastic pellets they mistake for fish eggs.

23. Overfishing

24. Sustainable yield: the optimal annual catch that can be derived indefinitely from harvested species, without causing a stock failure.
96 million metric tons of fishes, shellfish and algae are taken yearly by commercial fishermen. Almost 30% of this catch is never used for human consumption.
100 million metric tons is the limit advised by United Nations Food and Agriculture Organization.

25. 85% of species currently fished in American waters are now overexploited.
At least 14 species of fish have been so seriously depleted it may take 20 years to recover assuming all fishing were to stop.

26. Why Fish?
Over half the population of developing nations depends on fish as its primary source of dietary protein.
Fishing contributes to economic stability.

27. Who’s to Blame?
Sophisticated fishing equipment allows fishing boats to locate large schools of fish with speed and accuracy.
TRAWLS and immense gill nets (40 ft long, 500 ft deep) sweep everything in their path including turtles, dolphins and sharks.
With shrimp fishing the trawl mesh so small that for every 1 lb shrimp taken, 10 lbs of bycatch is caught.

28. Effects
Selectively fish out the larger, more desirable members of certain species.
Create inferior breeds, which mature and reproduce earlier, have fewer offspring, and have a shorter lifespan.

29. Lionfish
Alien Species
Organisms that have been introduced into a new marine environment.
In their introduced environment, no natural predators exist.
Can restructure the food web, introduce diseases, and compete with and prey on native organisms.
Caulerpa
Zebra mussel

30. How Are Alien Species Introduced?
Ballast water - Large ships take on extra water into their ballast tanks to maintain stability in the open ocean. The water is then discharged in the new port, introducing new organisms.
Aquaculture – Species such as fish, shellfish and seaweeds raised in pens may escape or be released into local waters.
Seafood trade- Species purchased as seafood may be later dumped or released into local waters.

31. Whaling
The hunting of whales for commercial use and “research” purposes.
Countries that still conduct whaling include Japan, Iceland and Norway even though there is little market for whale meat.