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CHAPTER 19 & 20
OCEANS IN JE
OPARDY
Potomac
Rappahannock
York
James
Patuxent
Patapsco
Susquehanna
Chester
Choptank
Nanticoke
Pocomoke
THE CHESAPEAKE BAY
• largest estuarine system in the United States
• has a watershed of almost 64,000 square miles.
• This unique ecosystem also contains more than 1,500 square miles of wetlands that provide critical habitat for fish, shellfish, and wildlife; filter and process residential, agricultural, and industrial wastes; and buffer coastal areas against storm and wave damage.
THE CHESAPEAKE BAY
• Five major tributary systems--the Potomac, Susquehanna, Rappahannock, York, and James Rivers
• Major Problems facing the bay: Overfishing, Overharvesting, Nutrient Overload, Toxic Chemicals, Pollution, Habitat Destruction
“Clean Water Act”
Reading and Questions
POLLUTION
Ocean dumpingtrash – 17th annual Coastal Cleanup in September 20022.8 million lb. of trash and debris in 3 hours1.3 million cigarette butts and filters226,251 glass bottles238,826 metal cans2,529 syringes61% of trash collected was plastic82 animals found trapped in the debris
POLLUTION
Ocean dumping (continued)plasticstrength and durability of plastic make it one of the most hazardous materials in the sea
commercial dumpinggarbage, sewage and toxic chemicals have been dumped into the New York Bight since 1890
GARBAGE ISLA
ND
DOCUMENTARY
It is estimated there are more than 13,000 pieces of plastic litter on every square
kilometer of the ocean surface.
(1 Km= .6 miles)
THE WATERS OFF THE NEW YORK/NEW JERSEY COASTS WERE ONCE SO CONTAMINATED THEY WERE THE JOKE OF THE NATION. THE NY/NJ BIGHT WAS KNOWN AS THE "OCEAN DUMPING CAPITAL OF THE WORLD" DUE TO EIGHT OCEAN DUMPSITES. THIS MAP INDICATES THE LOCATION OF THESE OCEAN DUMPSITES.
POLLUTION
Ocean dumping (continued)military refusediscarded military hardware and munitions
toxic gases and chemicalsradioactive wastesdisposal of radioactive materials in trench subduction zones has been proposed
In 1964, mustard gas canisters are pushed into the Atlantic Ocean off New Jersey. Millions of pounds were dumped this way.
HUNDREDS OF DOLPHINS WASHED ASHORE IN VIRGINIA AND NEW JERSEY SHORELINES IN 1987 WITH BURNS FROM TO MUSTARD GAS EXPOSURE.
POLLUTION
Pollution via land and airurban pollution50% of the U.S. population lives within 50 miles of coastline (including the Great Lakes)
this population needs energy, industry and waste treatment
coastal seas and habitats are polluted by associated runoff from landpesticides, fertilizers, gasoline, oil, sewage, chemicals used to treat sewage
POLLUTION
Pollution via land and air (continued)pesticides and toxic materials from industrypesticides (e.g. DDT), toxic organic compounds (e.g. PCBs), heavy metals (e.g. mercury, lead, zinc, and chromium)
biological magnification—concentration of toxins in the tissues of animals as they are passed up the food chain without being broken down or excreted
POLLUTION
Pollution via land and air (continued)air pollutionsulfur dioxide from burning of fossil fuels can precipitate in water and lower pH
greenhouse gases (e.g. CO2, methane) contribute to global warming
global warning is thought to cause coral bleaching, raise sea levels, killing corals that must remain close to the surface to obtain sufficient sunlight for zooxanthellae
POLLUTION
Nutrient pollutionhuman wastesdisease agentscoliform bacteria, found in the intestines of many animals, are counted to monitor water quality
eutrophication – leads to blooms of phytoplankton and other marine microbes
increased productivitysometimes, the addition of sewage and animal wastes can boost the productivity of a marine community
POLLUTION
Nutrient pollution (continued)agricultural wastesfertilizers and animal wastes have effects similar to those of human wastes
pesticides are also found in runoff from farms
POLLUTION
Controlling pollutionlegislation 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
THE 11TH HOUR
POLLUTION
Petroleum pollution
petroleum productscrude oil contains aromatic hydrocarbons and aliphatic hydrocarbons
aromatic hydrocarbons—molecules made up of carbon atoms in ring structures (e.g. benzene, naphthalen, cyclohexane)
POLLUTION
Petroleum pollutionpetroleum productsaliphatic hydrocarbons—straight-chain molecules (e.g. heptane, octane, nonane)
petroleum products are persistent, difficult for microbes to degrade, and toxic to organisms
POLLUTION
Petroleum pollution (continued)oil spillslargest oil spill in the U.S. was in March 1989, when the tanker Exxon Valdez ran onto a rocky reef 25 miles from Valdez, Alaska
largest and longest-lasting oil spill ever was in June 1979, when an offshore oil well in the Gulf of Mexico, the Ixtoc 1, blew out and caught fire
oil spills are deadly for marine organisms
POLLUTION
Petroleum pollution (continued)ecological effects of oil spillseffects on birds and mammalseffects on invertebrates and algaecommunity effects
BP OIL SPILL
BP OIL SPILL
210 million gallonsfar bigger than Exxon Valdez,
making it the worst spill in American history.
The National Wildlife Federation reports that already more than:
150 threatened or endangered sea turtles are dead
316 sea birds, mostly brown pelicans and northern gannets, have been found dead
POLLUTION
Petroleum pollution (continued)oil spill cleanupoil booms and oil skimmers help to confine the spill to a smaller area and recover some of the oilstraw is used to soak up the oil, then burneda bacterium genetically engineered to degrade crude oil is being tested
HABITAT DESTRUCTION
Wetlandsprovide 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”
HABITAT DESTRUCTION
Beachesdirect effects of beach use and development on marine lifedisturbs nesting sites of birds, sea turtles and horseshoe crabs
destruction of habitatinterfering with natural processeslongshore 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
Oceans in Peril:
Overfishing
AN OCEAN IN CRISIS
The oceans are facing collapse due to overfishing.
According to the U.N. Food and Agriculture Organization 75
percent of the world's fisheries are now either overexploited, fully exploited, significantly depleted or recovering from
overexploitation.
Biggest single threat to marine ecosystems today is overfishing.
Overfishing: catching so many fish that too few are left in the ocean to reproduce at rates that can sustain a healthy population
Demand for fish is exceeding ecological limits with devastating impacts
Overfishing results in profound changes in our oceans
A large yellow fin tuna being cut up.
Yellow fin and big eye tuna may be commercially extinct in 3-5 years
BETTER CHOICES
Alaska King CrabCatfish (farmed)Clams Crab: Blue, Dungeness, KingCrawfishHalibut (Pacific)Mussels (Black, Green-lipped)Oysters (farmed)Pollack (Alaska)Prawns (trap-caught, Pacific)Rock Lobster (Australian) Salmon (Wild Alaskan)Scallops (Bay - farmed)Shrimp (US farmed)Squid (Pacific)Tilapia (farmed)Tuna: Pacific Albacore
END OF
THE LI
NE
EPILOGUE
• Natural changes are small and occur over long periods of time
• Changes caused by humans can be instantaneous and involve entire marine communities
• Understanding the underlying patterns and processes of the sea allows people to use the sea’s resources without jeopardizing its environmental or economic value for the future