1. Coastal Areas — Why do we care?

2. Popular More than 60% of world’s population lives within 60 miles of the coast.

5. Coastal Areas — Why do we care? Popular Vulnerable

6. US Shoreline Erosion

7. Sea levels rose 10 inches over the past 100 years Expected to rise 2 more feet over next 100 years Would rise more than 200 more feet if only Antarctica melted

8. © 2011 Pearson Education, Inc. CHAPTER 11 The Coastal Ocean

9. © 2011 Pearson Education, Inc. Chapter Overview Coastal waters support about 95% of the total biomass in the oceans. Most commercial fish are caught within 320 km (200 miles) from shore. Coast waters are important also for shipping, oil and gas production, and recreation. Pollution is a major issue.

10. © 2011 Pearson Education, Inc. Ocean Ownership In 1609 the sea was free to all (mare liberum). –Assumed fish resources are inexhaustible In 1702 the territorial sea area was declared under the coastal nation’s sovereignty (3 nautical miles from shore). –Distance of cannon shot

11. © 2011 Pearson Education, Inc. United Nations Law of Sea United Nations Conference on the Law of the Sea –1958 –1960 –1973–1982 Treaties have undergone revisions.

12. © 2011 Pearson Education, Inc. Law of the Sea Coastal nations jurisdiction –National sovereignty extends 12 nautical miles –Exclusive Economic Zone (EEZ) 200 nautical miles (370 km) from land (mineral and fishing resources) Right of free passage for ships Open ocean mining regulated by International Seabed Authority United Nations arbitrates disputes

13. © 2011 Pearson Education, Inc. United States EEZ

14. © 2011 Pearson Education, Inc. Characteristics of Coastal Waters Adjacent to land (to edge of continental shelf) Influenced by river runoff, wind, tides

15. © 2011 Pearson Education, Inc. Characteristics of Coastal Waters Salinity variable –Freshwater runoff Can produce well-defined halocline –Winds –Mixing by tides Water may be isohaline

16. © 2011 Pearson Education, Inc. Characteristics of Coastal Waters Temperature variable –Low-latitudes – restricted circulation, very warm –High-latitudes – sea ice Water may be isothermal at low and high latitudes. –Seasonal changes –Prevailing winds –A strong thermocline may develop at middle latitudes.

17. © 2011 Pearson Education, Inc. Temperature Variation in Coastal Ocean

18. © 2011 Pearson Education, Inc. Types of Coastal Waters Estuaries –Partly enclosed body of water –Freshwater runoff dilutes ocean water. Where FW meets SW

19. © 2011 Pearson Education, Inc. Types of Estuaries Coastal plain estuary –Former river valley now flooded with seawater Fjord –Former glaciated valley now flooded with seawater Bar-built estuary –Lagoon separated from ocean by sand bar or barrier island Tectonic estuary –Faulted or folded downdropped area now flooded with ocean

20. © 2011 Pearson Education, Inc. Types of Estuaries

21. © 2011 Pearson Education, Inc. Water Mixing in Estuaries Vertically mixed –Shallow, low volume Slightly stratified –Deeper –Upper layer less salty; lower layer more salty –Estuarine circulation

22. © 2011 Pearson Education, Inc. Water Mixing in Estuaries Highly stratified –Deep, relatively strong halocline Salt wedge –Deep, high volume –Strong halocline

23. © 2011 Pearson Education, Inc. Estuary Classification by Mixing

24. © 2011 Pearson Education, Inc. Estuaries and Human Activities Important breeding grounds for many marine animals Protective nurseries Pressures from increasing human populations

25. © 2011 Pearson Education, Inc. Columbia River Estuary Salt wedge estuary Damage done by flooding of agricultural areas Dams altered ecosystem Logging industry damage

26. © 2011 Pearson Education, Inc. Chesapeake Bay Estuary Slightly stratified Seasonal changes in salinity, temperature, dissolved oxygen Anoxic conditions below pycnocline in summer Major kills of commercially important marine animals

27. © 2011 Pearson Education, Inc. Types of Coastal Wetlands Ecosystems intermittently inundated with ocean water Peat deposits and halophytic plants Salt Marshes –Between 30 and 65 degrees latitude Mangrove Swamps –Tropics

28. © 2011 Pearson Education, Inc. Locations of Salt Marshes and Mangrove Swamps

29. © 2011 Pearson Education, Inc.

30. Characteristics of Coastal Wetlands Biologically important –Nurseries, feeding grounds for commercially important marine animals Efficiently cleanse polluted water Absorb water from coastal flooding Protect shores from wave erosion It is a good thing we really take good care of our Estuaries, right???????

31. Global Patterns of Primary Productivity

32. Global Primary Production Upwelling areas –Very productive but smallest area Coastal areas –Intermediate productivity and area Open ocean –Least productive, but largest area –As productive as deserts on land Estuaries –As productive as the most heavily cultivated areas on land

34. © 2011 Pearson Education, Inc. Loss of Coastal Wetlands Half of U.S. coastal wetlands lost to development (housing, industry, agriculture) U.S. Office of Wetland Protection, 1986 –Minimize loss of wetlands –Protect or restore wetlands Predicted rise in sea level over next 100 years will destroy or shift wetlands inland

35. © 2011 Pearson Education, Inc. Loss of Coastal Wetlands

36. Estuary Where SW meets FW Of the 32 largest cities in the world, 22 are located on estuaries. For example, New York City is located at the opening of the Hudson River estuary.

37. Estuary Tidal Influence means flushing New water in with high tide = nutrients, food, oxygen Water leaves at low tide removes waste and CO 2 Flushing rate: high (fast) or low (slow)

38. Estuary Chesapeake Bay once had an oyster population that was able to filter the entire water system in 2 weeks. Now it takes about 1 year.

39. Salt Marsh

41. Wednesday Next Monday Pollution Part 1 Pollution Part 2 Wednesday March 30 EXAM #3 Chap 9, 10, 11 + Long Island + Pollution