20-4 What Are the Major Water Pollution Problems Affecting Oceans? Concept 20-4A The great majority of ocean pollution originates on land and includes oil and other toxic chemicals as well as solid waste, which threaten fish and wildlife and disrupt marine ecosystems. Concept 20-4B The key to protecting the oceans is to reduce the flow of pollution from land and air and from streams emptying into these waters.

Ocean Pollution Is a Growing and Poorly Understood Problem (1) Globally, since many people live near _____________ this area bears the brunt of our _________ of pollutants and wastes into the ocean 2006: State of the Marine Environment study conducted by UNEP… 80% of marine pollution originates on ___________ 80-90% of municipal sewage from coastal LDCs is dumped into oceans _____________ treatment __________________ the coastal area’s ability to breakdown biodegradable waste Extra nutrients also causes excess ________________ coastlines input land without Overwhelm algal growth

China’s Coastline Choked by Algae

Ocean Pollution Is a Growing and Poorly Understood Problem (2) In deeper ocean waters, the ocean can ____________, disperse, and degrade large amounts of raw sewage and degradable pollutants Some scientist argue that it is ____________ to dump harmful waste into deep oceans rather than… ______________ it on land _____________ it in incinerators Others disagree since our knowledge of the deep ocean is ___________________ and this would delay pollution _______________ measures dilute safer bury burn limited prevention

Ocean Pollution Is a Growing and Poorly Understood Problem (3) Cruise line pollution: what is being dumped? ________________ Toxic __________________ Such dumping is illegal in U.S. waters, but this is difficult to monitor garbage sewage waste oil chemicals

Ocean Pollution Is a Growing and Poorly Understood Problem (4) Recent studies of some U.S. coastal waters have found vast colonies of ____________ thriving in effluents from sewage treatment plants (which do not remove viruses) ______ of people using such waters have developed… Ear infections Sore throats Eye irritations Respiratory diseases Gastrointestinal diseases viruses 1/4

Fig , p. 545 Industry Nitrogen oxides from autos and smokestacks, toxic chemicals, and heavy metals in ef fl uents fl ow into bays and estuaries. Cities Toxic metals and oil from streets and parking lots pollute waters; sewage adds nitrogen and phosphorus. Urban sprawl Bacteria and viruses from sewers and septic tanks contaminate shellfish beds and close beaches; runoff of fertilizer from lawns adds nitrogen and phosphorus. Construction sites Sediments are washed into waterways, choking fish and plants, clouding waters, and blocking sunlight. Farms Runoff of pesticides, manure, and fertilizers adds toxins and excess nitrogen and phosphorus. Red tides Excess nitrogen causes explosive growth of toxic microscopic algae, poisoning fish and marine mammals. Closed shellfish beds Closed beach Oxygen-depleted zone Toxic sediments Chemicals and toxic metals contaminate shellfish beds, kill spawning fish, and accumulate in the tissues of bottom feeders. Oxygen-depleted zone Sedimentation and algae overgrowth reduce sunlight, kill beneficial sea grasses, use up oxygen, and degrade habitat. Healthy zone Clear, oxygen-rich waters promote growth of plankton and sea grasses, and support fish.

Ocean Pollution Is a Growing and Poorly Understood Problem (5) Runoffs of sewage and agricultural wastes into coastal waters introduce large quantities of ___________ (NO 3 - ) and _______________ (PO 4 3- ) These are considered plant _____________, which cause explosive growths of harmful ______________. These harmful algal blooms (HABs) are called red, brown, or green __________ - can release waterborne and airborne toxins that… poison seafood Damage fisheries Kill some fish-eating birds Reduce tourism serc.carleton.edu nitrate phosphate nutrients algae tides

Science Focus: Oxygen Depletion in the Northern Gulf Of Mexico Excess nutrients can also lead to _______________ zones The world’s _________ largest oxygen-depleted zone forms every spring and summer in the Gulf of Mexico off of the mouth of the _______________ River Excess nutrients derived from the vast Mississippi River ____________ (watershed) Highly productive farming area oxygen-depleted 3rd Mississippi Basin

A Large Zone of Oxygen-Depleted Water in the Gulf of Mexico Due to Algal Blooms Fig. 20-B, p. 546

A Large Zone of Oxygen-Depleted Water in the Gulf of Mexico Due to Algal Blooms Recall, that excess nutrients cause increased plant or algal ____________...as these organisms decompose, the DO levels in the area ___________. The low-oxygen levels ______________ fish, crabs, and shrimp that cannot move out of the area Possible tipping point? Solutions? Use ________ fertilizer Use techniques to reduce soil _______________ ________________ sewage treatment plants Lower emissions of nitrogen oxides from _____________ Fig. 20-B, p. 546 growth drop suffocate less erosion Upgrade vehicles

Plastic Waste In 1997, ocean researchers discovered a huge swirling mass of plastic waste in the North Pacific Ocean Due mainly to __________ pieces of plastic “human throw away mentality” _________________________________ Discovered a similar one in 2010 in the Atlantic Ocean…called the ______________________________ Leading to increased plastic _________________ by marine organisms and birds Midway a Message from the Gyre small Great Pacific Garbage Patch Great Atlantic Garbage Patch ingestion

Ocean Pollution from Oil (1) Both crude and refined petroleum reach the ocean from a number of sources Crude petroleum – oil as it comes out of the ________ Refined petroleum – processed petroleum __________ like fuel oil, diesel, gasoline Tanker accidents get the most press, but studies show that the largest source of ocean pollution from oil is urban and industrial runoff from __________ ground products land

Ocean Pollution from Oil (2) Damaging effects of oil… Volatile organic hydrocarbons in oil _______ many aquatic organisms immediately upon contact Other chemicals in oil form tarlike _________ that float on the ocean surface and coat the _____________ of seabirds and ___________ of marine mammals Destroys their natural heat _________________ or __________________ Heavy oil components ___________ to the ocean floor or wash into estuaries and smother ______________- dwelling organisms kill globs feathers fur insulation buoyancy sink bottom

Ocean Pollution from Oil (3) Damaging effects of oil… Serious local economic impact to _______________ and _________________ industry Oil Clean Up? Can be partially cleaned or contained by mechanical means – floating ___________, skimmer boats, and absorbent devices Oil eating bacteria? Dispersant chemicals? tourism fishing booms

Ocean Pollution from Oil (4) Scientists estimate that current clean up methods can recover no more than ______ of the oil from a major spill. _________________ oil pollution is the most effective and least costly approach 15% Preventing

BP Deepwater Horizon Blowout in the Gulf of Mexico, April 20, 2010 Fig , p. 547

BP Deepwater Horizon Blowout in the Gulf of Mexico, April 20, 2010 Blow out caused by oil and natural gas escaping from a well that lead to an explosion The blow out preventer in this situation __________ and there was not an effective Plan B in place Crude oil flowed out of the well until it was effectively “capped” nearly 3 months later failed

Case Study: The Exxon Valdez Oil Spill 1989: The Exxon Valdez oil tanker went off course, collided with a reef, and released ____________ liters of crude oil into Alaska’s Prince William Sound 5200 km of coastline Killed 250,000 seabirds $15 billion in damages to economy Exxon paid $3.8 billion in damages and clean-up costs Led to improvements in oil tanker __________ and clean-up ________________ 41 million safety methods

Fig , p. 547 Coastal Water Pollution PreventionCleanup Reduce input of toxic pollutants Improve oil-spill cleanup capabilities Separate sewage and storm water lines Use nanoparticles on sewage and oil spills to dissolve the oil or sewage (still under development) Ban dumping of wastes and sewage by ships in coastal waters Ban dumping of hazardous material Require secondary treatment of coastal sewage Strictly regulate coastal development, oil drilling, and oil shipping Use wetlands, solar- aquatic, or other methods to treat sewage Require double hulls for oil tankers Solutions

Review Questions What is another term for a harmful algal bloom (HAB)? Why does an oxygen depleted zone form every spring and summer near the mouth of the Mississippi River? The largest source of ocean pollution from oil is urban and industrial runoff from ____________. Red tide (green or brown) Excess nutrients move there from a large watershed area… More plant growth and decomposition – drop in DO land