AP Environmental Science Mr. Grant Lesson 80

1. AP Environmental Science • Mr. Grant • Lesson 80 Marine and Coastal Ecosystems & Marine Pollution

2. Objectives: • Define the term by-catch. • Describe major types of marine ecosystems. • Assess impacts from marine pollution.

3. Define the term by-catch. • By-Catch: Unwanted marine creatures that are caught in the nets while fishing for another species; "thousands of dolphins and porpoises and whales are killed as part of the by-catch each year"

4. Describe major types of marine ecosystems. • Major types of marine and coastal ecosystems include pelagic and deep-water open ocean systems, kelp forests, coral reefs, intertidal zones, salt marshes, mangrove forests, and estuaries. • Many of these systems are highly productive and rich in biodiversity. Many also suffer from human influence.

5. Marine and coastal ecosystems Regions of ocean water differ greatly Some zones support more life than others Photic zone = well-lighted top layer Absorbs 80% of solar energy Supports high primary productivity Pelagic = habitats and ecosystems between the ocean’s surface and floor Benthic = habitats and ecosystems on the ocean floor Most ecosystems are powered by solar energy But even the darkest depths host life

6. Open ocean systems vary in biodiversity Microscopic phytoplankton are the base of the marine food chain Algae, protists, cyanobacteria They feed zooplankton Which then feed fish, jellyfish, whales, etc. Predators at higher trophic levels Larger fish, sea turtles, sharks, and fish-eating birds

7. Animals of the deep ocean Animals adapt to extreme water pressure and the dark Scavenge carcasses or organic detritus Predators Others have mutualistic relationships with bacteria Some carry bacteria that produce light chemically by bioluminescence Hydrothermal vents support tubeworms, shrimp, and other chemosynthetic species

8. Kelp forests harbor many organisms Kelp = large, dense, brown algae growing from the floor of continental shelves Dense strands form kelp forests along temperate coasts They provide shelter and food for organisms They absorb wave energy and protect shorelines from erosion People use it in food, cosmetics, paints, paper, soap, etc.

9. Coral reefs are treasure troves of biodiversity Coral reef = a mass of calcium carbonate composed of the skeletons of tiny marine animals (corals) They may be an extension of a shoreline Or exist along a barrier island, parallel to the shore Or as an atoll (a ring around a submerged island) Corals = tiny colonial invertebrate animals Related to sea anemones and jellyfish Attach to a rock or reef and capture passing food with stinging tentacles Get food from symbiotic algae (zooxanthallae)

10. Most corals are colonial Reefs consist of millions of densely packed animals Reefs are located in shallow subtropical and tropical waters Protect shorelines by absorbing waves Innumerable invertebrates and fish species find food and shelter in reef nooks and crannies

11. Coral reefs are in worldwide decline “Coral bleaching” = occurs when zooxanthellae leave the coral or die Corals lose their color and die, leaving white patches From climate change, pollution, or unknown natural causes Nutrient pollution causes algal growth Which smothers coral Divers damage reefs by using cyanide to capture fish Acidification of oceans deprives corals of carbonate ions for their structural parts

12. Deepwater coral reefs exist They thrive in waters outside the tropics On ocean floor at depths of 200–500 m (650–1,650 ft) Occur in cold-water areas off the coasts of Spain, the British Isles, and elsewhere Little is known about these reefs Already, many have been badly damaged by trawling Some reefs are now being protected

13. Intertidal zones undergo constant change Intertidal (littoral) ecosystems =where the ocean meets the land Between the uppermost reach of the high tide and the lowest limit of the low tide Tides = periodic rising and falling of the ocean’s height due to the gravitational pull of the sun and moon Intertidal organisms spend part of their time submerged in water and part of their time exposed to sun and wind

14. A typical intertidal zone

15. Intertidal zones are a tough place to live But they have amazing diversity Rocky shorelines, crevices, pools of water (tide pools) Anemones, mussels, barnacles, urchins, sea slugs Starfish and crabs Temperature, salinity, and moisture change dramatically from high to low tide Sandy intertidal zones have slightly less biodiversity

16. Salt marshes line temperate shorelines Salt marshes = occur along coasts at temperate latitudes Tides wash over gently sloping sandy, silty substrates Tidal creeks = channels that rising and falling tides flow into and out of Salt marshes have very high primary productivity Critical habitat for birds, commercial fish, and shellfish They filter pollution They stabilize shorelines against storm surges

17. People change and destroy salt marshes People want to live or do business along coasts We lose key ecosystem services Flooding (e.g., from Hurricane Katrina) worsens

18. Mangrove forests line coasts In tropical and subtropical latitudes They replace salt marshes along sandy coasts Mangroves = salt-tolerant trees Their unique roots curve up for oxygen and down for support Nesting areas for birds Nurseries for fish and shellfish Mangroves provide food, medicine, tools, and construction materials

19. Mangrove forests have been destroyed Half the world’s mangrove forests are gone Developed for residential, commercial, and recreational uses Shrimp farming Once destroyed, coastal areas no longer: Slow runoff Filter pollutants Retain soil Protect communities against storm surges

20. Fresh and salt water meet in estuaries Estuaries = water bodies where rivers flow into the ocean, mixing fresh and salt water They are biologically productive Have fluctuations in salinity Critical habitat for shorebirds and shellfish Transitional zone for fish that spawn in streams and mature in salt water They have been affected by development, pollution, habitat alteration, and overfishing

21. Assess impacts from marine pollution. • People pollute ocean waters with trash, including nets and plastic that harm marine life. • Plastic trash accumulate in ocean regions where it is trapped by currents. • Marine oil pollution results from non-point sources on land as well as from spills at sea from tankers and drilling platforms. • Heavy metal contaminants in seafood affect human health. • Nutrient pollution can lead to dead zones and harmful algal blooms.

22. Marine pollution People use oceans as a sink for waste and pollutants Even into the mid-20th century, coastal U.S. cities dumped trash and untreated sewage along their shores Nonpoint source pollution comes from all over Oil, plastic, chemicals, excess nutrients In 2008, 391,000 Ocean Conservancy volunteers from 104 nations picked up 3.1 million kg (6.8 million lb) of trash from 27,000 km (17,000 miles) of shoreline

23. Nets and plastic debris endanger life Plastic items dumped into the sea harm or kill wildlife Wildlife mistake it for food 98% of dead northern fulmars had plastic in their stomachs Plastic is nonbiodegradable Drifts for decades Breaks into tiny pieces Trillions of tiny plastic pellets float in the oceans and are eaten

24. Plastic trash is accumulating in the oceans Circulating currents bring and trap plastic trash to areas The northern Pacific Gyre stretches from California to Hawaii to Japan This “Great Pacific Garbage Patch” is the size of Texas and has 3.3 plastic bits/m2 The 2006 Marine Debris Research, Prevention, and Reduction Act is not enough We must reduce, reuse, and recycle more plastic Participate in efforts such as the International Coastal Cleanup

25. Oil pollution comes from spills of all sizes 30% of oil and 50% of natural gas come from seafloor deposits North Sea, Gulf of Mexico Drilling in other places is banned Spills could harm valuable fisheries The Deepwater Horizon exploded off Louisiana’s coast in April 2010 Spilling 140 gallons/min Hitting coasts of four states

26. Oil spills have severe consequences Major spills make headlines Foul beaches Coat and kill animals Devastate fisheries Countless non-point sources produce most oil pollution Small boat leaks, runoff Major oil spills cause severe environmental and economic problems

27. Oil spills have decreased Due to emphasis on spill prevention and response Stricter regulations are resisted by the oil industry The U.S. Oil Pollution Act (1990) Created a $1 billion prevention and cleanup fund Requires that all ships have double hulls by 2015 Recently, oil spills have decreased

28. Toxic pollutants contaminate seafood Toxic pollutants can make food unsafe to eat Mercury contamination from coal combustion and other sources bioaccumulates and biomagnifies Dangerous to children and pregnant or nursing women Avoid eating swordfish, shark, and albacore tuna Eat seafood low in mercury (catfish, salmon, canned light tuna) Avoid seafood from areas where health advisories have been issued

29. Excess nutrients cause algal blooms Harmful algal blooms = nutrients increase algae that produce powerful toxins Red tide = algae that produce red pigments that discolor water Illness and death to wildlife and humans Economic loss to fishing industries and beach tourism Reduce runoff Do not eat affected organisms