1. Chapter 20
Oceans in Jeopardy

2. Pollution Ocean dumping Ocean as dumping site for trash & garbage
17th annual Coastal Cleanup in September 2002 cleaned 5,148 miles of U.S. coastlines
2.8 million lbs. of trash and debris in 3 hours
1.3 million cigarette butts and filters
226,251 glass bottles 238,826 metal cans
2,529 syringes
61% of trash collected was plastic
82 animals found trapped in the debris

3. © 2006 Thomson-Brooks Cole

5. Pollution Ocean dumping plastic
strength and durability of plastic make it one of the most hazardous materials in the sea
Remains in marine environment for a very long time

6. Marine animals and plastic:
Discarded/lost traps ensnare animals (die of starvation)
Suffocated by plastic bags & sheets of plastic
Ingested plastics form an indigestible mass blocking digestive tract leading to starvation
Plastics absorb other pollutants in the water such as PCB’s

7. Great Pacific Garbage Patch
In central north Pacific Ocean
High concentrations of plastics, chemical sludge and other debris that have been trapped by the North Pacific Gyre
Estimated to be size of Texas up to “twice the size of the continental United States.”

8. Pollution Ocean dumping
Controlling plastic – Marine Plastic Pollution Research and Control Act of 1987
Prohibits dumping of plastic in ocean
Requires ports & terminals to provide facilities for disposal of this waste
US Navy can still legally dump trash & plastic in the ocean
Enforced by the Coast Guard
International agreement prohibits dumping of plastic in ocean
Trouble with enforcement

9. Pollution Commercial dumping
Example: garbage, sewage and toxic chemicals have been dumped into the New York Bight (near mouth of Hudson River) since 1890
1.4 million cubic meters of solid waste dumped between 1890 and 1971
EPA closed offshore dump in 1987

10. Ocean dumping: military refuse
Discarded military hardware and munitions following major wars
For example after WWII:
Toxic gases and chemicals from Germany in Atlantic
Jeeps, tanks, trucks, and munitions in Pacific
Waste can entangle or poison marine birds or mammals
Metallic waste can also be converted into artificial reefs

11. Pollution Radioactive waste
Disposal of radioactive materials in subduction zones has been proposed
Wastes ultimately be taken into the mantle eliminating need for long term storage
Prohibited by the Ocean Dumping Act of 1972, which requires an environmental impact statement and approval of the House and Senate

12. Pollution via land and air Urban pollution
Major population centers along coastline (estuaries and rivers that drain into them)
Need energy, industry and waste treatment
Coastal seas and habitats are polluted by associated runoff from land
pesticides, fertilizers, gasoline, oil, sewage, chemicals used to treat sewage, etc.

13. Pollutants carried into the sea by rivers and washed into the sea by rainwater and melting snow.
© 2006 Thomson-Brooks Cole

14. Pollution Pesticides and toxic materials from industry
Pesticides (ex. DDT), toxic organic compounds (ex. PCBs), heavy metals (ex. mercury, lead, & zinc)
Continue to enter the sea through runoff from land even though banned

15. Biomagnification:
Concentration of toxins in the organisms increases as toxins are passed up the food chain without being broken down or excreted
Eventually concentration of toxin or chemical will be high enough to cause serious illness or death

16. Biological Magnification: Toxins accumulate in tissues of consumers
Biological Magnification: Toxins accumulate in tissues of consumers. Toxins are not broken down or excreted by organisms. Ultimately the toxin will reach a deadly level in a higher order consumer.
© 2006 Thomson-Brooks Cole

17. What is DDT?
Manufactured to control insects on agricultural crops and insects that carry diseases like malaria and typhus.
Does not occur naturally in the environment.
Persistent organic pollutant.
Banned in the United States (1972).
Still used in some countries.
Limited controversial use for disease vector control in some countries.

18. Exposure to DDT? Builds up in plants and the fatty tissue of animals
Eating food is the primary source of exposure for the general human population
Breathing contaminated air or drinking contaminated water
Skin contact with contaminated soil surfaces
Nursing on human breast milk from mothers who have been exposed

19. Effects of DDT Exposure
Mostly affects the nervous system.
Early signs of poisoning include:
changes of the feeling in the face, hands, and feet
headache, dizziness, nausea, vomiting, incoordination, and tremors
More severe poisonings cause seizures and possibly coma or death.

20. Effects of DDT Exposure
Exposure to DDT or breakdown products (DDE and DDD) has possible cancer link in humans.
Liver cancer, breast cancer, lymphoma, leukemia, and pancreatic cancer.
Possible endocrine disruption, diabetes and developmental problems.
Toxic for many aquatic invertebrate species.
Toxic for many fish species.

21. Pollution
PCBs also have possible cancer link, liver disease, immune effects, & impaired cognitive development
Polychlorinated biphenyls
Synthetic organic compounds used in manufacturing & production
transformers, plasticizers, hydraulic fuels and lubricants, paints, pesticides, fire retardants, printing ink, etc.
Banned in 1979
Persistent

22. PCBs
Build up in living organisms both by uptake from the environment over time and along the food chain.
Stored primarily in fatty tissues.
PCB metabolism depend both on the animal species and on the specific PCB.
Some PCBs more persistent than others – depends on molecular structure.
Broken down by sunlight & microorganisms

23. PCB Exposure Eating contaminated food primary route of exposure.
Accumulate in fat rich tissues such as brain, liver, and skin.
Can be transformed to persistent metabolites that remain in tissues.
Increased risk of certain cancers of the digestive tract, liver and skin.
Reproductive deficiencies and weakened immune system.

24. Pollution Effects of toxic compounds on plankton
Toxic pollutants inhibit photosynthesis, growth, and cell division
Could lead to a reduction in marine primary productivity…

25. Pollution Air pollution
Sulfur dioxide from burning of fossil fuels can precipitate in water and lower pH of seawater
Greenhouse gases (e.g. CO2, methane) contribute to global warming
Coral bleaching (loss of color of corals, due to stress-induced expulsion of symbiotic unicellular algae or due to the loss of pigmentation within the algae)
Melting of glaciers & polar ice

26. Pollution Nutrient pollution Human wastes
Reduce water quality by adding harmful microorganisms & nutrient enrichment
Disease agents
Filter feeders (clams, mussels, etc) can concentrate microbes (hepatitis virus and Salmonella bacteria) in tissue; cause diseases if eaten
Coliform bacteria, found in the intestines of many animals, are counted to monitor water quality (amount of animal waste entering water)

27. Pollution
Eutrophication: increase in amount of dissolved nutrients in water
– leads to blooms of phytoplankton and other marine microbes
Interfere with primary productivity at greater depths; excessive decomposition after death leads to oxygen depletion & affects respiration for other organisms
Increased productivity
It has been observed that sometimes the addition of sewage and animal wastes can boost the productivity of a marine community for short time periods…

28. Pollution Nutrient pollution (continued) agricultural wastes
fertilizers and animal wastes have effects similar to those of human wastes
Eutrophication and addition of disease causing microbes
Agricultural nutrients carried by Mississippi River to Gulf of Mexico caused hypoxic zone (water with abnormally low oxygen content)
pesticides are also found in runoff from farms
Can poison the water…

29. Hypoxic Zone: Agricultural nutrients draining into the Gulf of Mexico have contributed to the depletion of oxygen in an area off Louisiana referred to as the “dead zone.”
© 2006 Thomson-Brooks Cole

30. Pollution Controlling pollution
legislation was passed to prohibit dumping of sewage sludge or industrial wastes in the ocean after Jan. 1, 1992
largest threat is increasing coastal populations and improperly controlled commercial and residential development…

31. Petroleum Pollution Petroleum products
crude oil contains 2 major types of organic molecules: aromatic hydrocarbons and aliphatic hydrocarbons

32. Aromatic hydrocarbons: molecules made up of carbon atoms in ring structures

33. Petroleum Pollution
aliphatic hydrocarbon:straight-chain molecules.

34. Petroleum Pollution Petroleum products persistent
difficult for microbes to degrade
toxic to organisms
Oil spills
Prior to spill in the Gulf, the largest oil spill in the U.S. in March 1989, when the tanker Exxon Valdez ran onto a rocky reef 25 miles from Valdez, Alaska
10 million gallons of oil into Prince William Sound

35. Petroleum Pollution Ecological effects of oil spills
Effects on birds and mammals
Impairs ability of bird to fly or swim
Impairs ability of feathers to insulate; possible hypothermia
Birds may ingest fatal amounts oil when cleaning
In otters destroys the ability of the fur to insulate leading to hypothermia
Clogs nostrils & eyes
Possible cancer link

36. Petroleum Pollution Effects on invertebrates and algae
On sandy shore killed by toxic oil components or smothered
Flesh of intertidal invertebrates becomes tainted & is passed along food chain
Community effects: decrease in species diversity in intertidal zone & simplification of the food web…

37. BP Oil Spill - Deepwater Horizon
Began with explosion and sinking of Deepwater Horizon oil rig.
Wellhead blowout
Spill date April 20, 2010 until July 15, 2010 (wellhead capped)
Officially sealed September 19, 2010 and considered “effectively dead”
More than 200 million gallons (approx. 4.9 million barrels) of crude oil was pumped into the Gulf of Mexico for a total of 87 days.
16,000 total miles of coastline affected.
Texas, Louisiana, Mississippi, Alabama, and Florida

38. BP Oil Spill - Deepwater Horizon
Over 8,000 animals (birds, turtles, mammals) were reported dead just 6 months after the spill.
Considered largest accidental marine oil spill.
Residual oil still present.
Recurrent or continued leakage?

39. Petroleum Pollution Oil spill cleanup Containment
Oil booms and oil skimmers help to confine the spill to a smaller area and recover some of the oil
Adsorbents
Straw and other materials used to soak up the oil
Feathers
Often burned
Air pollution

40. Petroleum Pollution Biodegradation Burning Dispersants
Debate on effectiveness
Bacterium genetically engineered to degrade crude oil
Burning
Air pollution
Dispersants
Breaks up oil to help facilitate degradation by microbes
Adding more toxic chemicals to area
Sinks oil harming organisms below surface

42. Oil kills molluscs, allowing seaweeds to overgrow the intertidal rocks – decreases biodiversity in the area.

43. Habitat Destruction Wetlands
provide nutrients, shelter and spawning grounds for a variety of marine organisms
have been drained, filled or dredged to provide more ground for industry, channels into ports/harbors, and beach-front real estate
legislation now protects wetlands, but the government continually changes the definition of “wetlands”

44. Habitat Destruction Beaches
direct effects of beach use and development on marine life
disturbs nesting sites of birds, sea turtles and horseshoe crabs
destruction of habitat
interfering with natural processes
longshore currents—generated by waves that break at an angle to the beach, moving parallel to the beach
longshore transport process—transport of sediments by longshore currents