Chapter 20 Oceans in Jeopardy © 2006 Thomson-Brooks Cole

Key Concepts Dumping wastes into coastal seas decreases their economic and recreational value and creates health hazards. Pollutants enter coastal seas by way of agricultural and urban runoff as well as by direct dumping. Some pollutants accumulate and magnify in food chains, posing serious problems for higher-order consumers… © 2006 Thomson-Brooks Cole

Key Concepts Plastic trash is deadly to large marine animals. Oil spills damage significant amounts of habitat and injure and kill marine life. Development of coastal areas leads to loss of habitat and diminished numbers of marine life… © 2006 Thomson-Brooks Cole

Key Concepts Destruction of wetlands results in decreased ocean productivity. It is not too late to become involved with conserving the oceans and their resources… © 2006 Thomson-Brooks Cole

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… © 2006 Thomson-Brooks Cole

© 2006 Thomson-Brooks Cole

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 long time 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… © 2006 Thomson-Brooks Cole

© 2006 Thomson-Brooks Cole

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 © 2006 Thomson-Brooks Cole

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… © 2006 Thomson-Brooks Cole

Pollution 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 © 2006 Thomson-Brooks Cole

Pollution radioactive wastes disposal of radioactive materials in subduction zones has been proposed Wastes ultimately be taken into the mantle eliminating need for long term storage currently, this is prohibited by the Ocean Dumping Act of 1972, which requires an environmental impact statement and approval of the House and Senate… © 2006 Thomson-Brooks Cole

Pollution 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… © 2006 Thomson-Brooks Cole

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

Pollution Pesticides and toxic materials from industry Pesticides (e.g. DDT), toxic organic compounds (e.g. PCBs), heavy metals (e.g. mercury, lead, & zinc) Continue to enter the sea through runoff from land even though banned DDT banned in 1960s; 1-7% of another pesticide (dicofol) used until 1988 DDT exposure linked to cancer & threat to birds (thin shelled eggs) PCBs also have possible cancer link, liver disease, immune effects, & impaired cognitive development © 2006 Thomson-Brooks Cole

Pollution Biological magnification Concentration of toxins in the tissues of animals increases as they 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 Effects of toxic compounds on plankton Toxic pollutants inhibit photosynthesis, growth, and cell division Could lead to a reduction in marine primary productivity… © 2006 Thomson-Brooks Cole

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

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 © 2006 Thomson-Brooks Cole

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) © 2006 Thomson-Brooks Cole

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… © 2006 Thomson-Brooks Cole

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… © 2006 Thomson-Brooks Cole

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

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… © 2006 Thomson-Brooks Cole

Petroleum Pollution Petroleum products crude oil contains 2 major types of organic molecules: aromatic hydrocarbons and aliphatic hydrocarbons © 2006 Thomson-Brooks Cole

Aromatic hydrocarbons: molecules made up of carbon atoms in ring structures © 2006 Thomson-Brooks Cole

Petroleum Pollution aliphatic hydrocarbon:straight-chain molecules. © 2006 Thomson-Brooks Cole

Petroleum Pollution Petroleum products are persistent, difficult for microbes to degrade, and toxic to organisms Oil spills largest 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 10 million gallons of oil into Prince William Sound © 2006 Thomson-Brooks Cole

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 © 2006 Thomson-Brooks Cole

Petroleum Pollution Effects on invertebrates and algae Invertebrates 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… © 2006 Thomson-Brooks Cole

Petroleum Pollution Oil spill cleanup oil booms and oil skimmers help to confine the spill to a smaller area and recover some of the oil straw is used to soak up the oil, then burned a bacterium genetically engineered to degrade crude oil is being tested Current legislation prevents use of this type of organism in nature Materials such as feathers used to be commonly used. © 2006 Thomson-Brooks Cole

© 2006 Thomson-Brooks Cole

Oil kills molluscs, allowing seaweeds to overgrow the intertidal rocks. © 2006 Thomson-Brooks Cole

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” © 2006 Thomson-Brooks Cole

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 © 2006 Thomson-Brooks Cole

© 2006 Thomson-Brooks Cole

© 2006 Thomson-Brooks Cole

© 2006 Thomson-Brooks Cole

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 © 2006 Thomson-Brooks Cole