1. Chemical and Physical Features of Seawater and the World Ocean

2. Much of our water is not drinkable due to elevated salinity and impurities Only 1 part in 10,000 of water is easily accessible for drinking and irrigation. However, between 85-95% of many organisms are comprised of mostly water. Water, water everywhere…and nor a drop to drink!” -from Rime of the Ancient Mariner by Samuel Taylor Coleridge (1798)

3. Water that is relatively pure, with very few dissolved salts Freshwater occurs in: Lakes, rivers, streams, groundwater, glaciers, rainwater, soil, water vapor in the atmosphere (In contrast, ocean water is salty because salts from land run into it and stay there as surface water evaporates.)

4. Figure 14.1 Only 2.5% of the planet’s water is freshwater, and only 1% of that exists on Earth’s surface.

5. The oceans consist of (by mass): 96.5% water 3.0% sodium and chlorine ions (table salt, Na + and Cl – ) 0.5% other salts Figure 13.3

6. All in all the total amount of salt dissolved in seawater, or salinity, is about 35 ppt. The concentrations of individual salts don’t vary much either, due to the rule of constant proportions*. Therefore, even if marine organisms are exposed to changes in total salinity, the changes in individual ion concentration remains similar.

7. Water density varies with salinity and temperature. Water density varies with salinity and temperature. If salinity or temperature increase, so does the density of the water. If salinity or temperature increase, so does the density of the water.

8. Seawater also does other cool stuff! Seawater also does other cool stuff! Light transmission -loose color at depth -loose color at depthPressure -increases 1 atmosphere for -increases 1 atmosphere for each 10 m increment each 10 m increment OUCH!

9. Part II: Ocean Circulation

10. Much of the circulation we might experience actually occurs at the surface. Wind drives much of the “ocean motion,” but something else plays a role, earth’s rotation. This is known as the Coriolis Effect.

11. Surface Currents All major surface currents are driven by the wind. All major surface currents are driven by the wind. Again, Coriolis Effect causes the surface waters to track Again, Coriolis Effect causes the surface waters to track toward the right (N. hemisphere). toward the right (N. hemisphere). Progressive spiraling caused Progressive spiraling caused by shallower currents pushing by shallower currents pushing on deeper currents results on deeper currents results in Ekman Spirals. in Ekman Spirals. As spirals continue, wind shear As spirals continue, wind shear becomes less and less at depth. becomes less and less at depth. Eventually, deep currents travel Eventually, deep currents travel ~90° to the wind direction. ~90° to the wind direction.

12. The final result: formation of gyres. El Niño and other large fluctuations can occur.

13. Ultimately this type of circulation affects the average temperatures in oceans in both hemispheres.

14. Upwelling refers to deep water that is brought to the surface. Areas of upwelling are created by surface winds that pull water away from an area. This deficit of water on the surface invites water to come up from deeper regions.

15. To understand upwelling, you must be familiar with how the Coriolis Effect affects ocean surface currents. The Coriolis Effect acts on moving water, because it is not attached to the rotating Earth. As water flows over the rotating earth, it appears to deflect to the right in the Northern Hemisphere and the left in the Southern.

16. The deep water that surfaces in upwelling is cold; by looking at Sea Surface Temperature maps we can identify cool upwelled water versus hotter surface water.

17. Upwelled water also contains nutrients (nitrate, phosphate, silicate) and dissolved gases (oxygen and carbon dioxide) that are not utilized at depth because of a lack of sunlight. Now on the surface, these nutrients and gases help to fuel photosynthesis by small algae called phytoplankton.

18. Phytoplankton photosynthesize using specialized color pigments called chlorophyll. Thus, “Ocean Color” maps are another way to identify areas of upwelling. Where on this ocean color map are high phytoplankton concentrations?

19. Ecological and Economic effects of upwelling: Upwelling leads to more phytoplankton More phytoplankton leads to more fish More fish lead to commercial fishing jobs and to more seafood

20. Even though upwelling areas account for only 1% of the ocean surface, they support 50% of the worlds fisheries.

21. Phytoplankton come in many shapes and forms. Collectively they form the base of oceanic food webs. Without upwelling many of the world’s fisheries would not thrive.

22. Some climatic events can reduce upwellings. El Nino ~

23. Along Peru’s coast, an El Nino event decreases the coastal winds. Thus the upwelling from below is slowed. An El Nino condition results from weakened trade winds in the western Pacific Ocean near Indonesia, allowing piled-up warm water to flow toward South America.

24. What is La Niña? La Niña is characterized by unusually cold ocean temperatures in the Equatorial Pacific, compared to El Niño, which is characterized by unusually warm ocean temperatures in the Equatorial Pacific.El Niño

25. Waves and Tides

26. A. Causes – wind and earthquakes B. Characteristics of Waves 1. crest – highest point of a wave 1. crest – highest point of a wave 2. trough – lowest point of a wave 2. trough – lowest point of a wave 3. wavelength – distance between 3. wavelength – distance between 2 adjacent wave crests or wave 2 adjacent wave crests or wave troughs troughs

27. VIII. Waves and Wave Action 10. swells – formation of long wavelength surface waves more stable than normal wind waves and formed by storms 10. swells – formation of long wavelength surface waves more stable than normal wind waves and formed by storms 11. deep water waves – waves that move in water deeper than ½ their wavelength 11. deep water waves – waves that move in water deeper than ½ their wavelength 12. shallow water waves – waves that reach water shallower than ½ their wave height 12. shallow water waves – waves that reach water shallower than ½ their wave height

28. VIII. Waves and Wave Action C. Tsunami – a great sea wave caused especially by undersea earth movement or volcanic eruption

29. VIII. Waves and Wave Action D. storm surge – an offshore rise of water often associated with a low pressure weather system, typically tropical cyclones E. undertow – the current beneath the surface that sets seaward or along the beach when waves are breaking on the shore F. longshore current – an ocean current that move parallel to the shore

30. VIII. Waves and Wave Action 6. wave height – vertical distance 6. wave height – vertical distance between crest and trough of a between crest and trough of a wave wave 7. breaker – high wave crest that 7. breaker – high wave crest that has been pulled down by gravity has been pulled down by gravity 8. surf – area between the breaker 8. surf – area between the breaker zone and the shore zone and the shore 9. white caps – wave crests breaking 9. white caps – wave crests breaking into white foam into white foam

31. Waves, the result of surface winds, have been responsible for many changes, some beneficial and some destructive.

32. Technically, the water never moves!

33. Surf is created as energy from the wave bunches and changes shape near the shore.

34. IX. Tides A. Tidal range – the vertical difference between high and low tides 1. high tides – occur twice a day, when the ocean water bulges as a result of the gravitational pull of the overhead moon 1. high tides – occur twice a day, when the ocean water bulges as a result of the gravitational pull of the overhead moon 2. low tides – occur twice a day, when the two areas of the earth are not experiencing high tide 2. low tides – occur twice a day, when the two areas of the earth are not experiencing high tide

35. IX. Tides B. Spring Tide – exceptionally high and low tides that occur at the time of the full and new moons, when the sun, earth, and moon are approximately aligned C. Neap Tide – times when the difference between high and low tide are minimized. Occur during quarter moons

36. How do tides happen?? Gravitational forces by the moon and the sun pulling on water cause the rise and fall of tides.

37. Since the earth rotates and the moon and sun, pull, tides occur at several intervals throughout the day.

39. Beaches and Shorelines Coast(shore) – region of contact between the oceans and the continents - continuously changes Beach- deposit of the shore area - consists of wave- worked sediment that moves along a wave cut beach - includes recreational beach berm beach face

40. Coastal waters are influenced by river runoff, wind and tides Salinity level can be variable due to river runoff halocline- layers of salinity levels

41. © 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.

42. © 2011 Pearson Education, Inc. Temperature Variation in Coastal Ocean

43. © 2011 Pearson Education, Inc. Types of Coastal Waters Estuaries Partly enclosed body of water Freshwater runoff dilutes ocean water.

44. © 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

45. © 2011 Pearson Education, Inc. Types of Estuaries

46. © 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

47. © 2011 Pearson Education, Inc. Estuaries and Human Activities Important breeding grounds for many marine animals Protective nurseries Pressures from increasing human populations

48. © 2011 Pearson Education, Inc. 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

49. © 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

50. © 2011 Pearson Education, Inc. Loss of Coastal Wetlands

51. © 2011 Pearson Education, Inc. Marine Pollution Pollution – Any harmful substance or energy put into the oceans by humans Harmful to living organisms Standard laboratory bioassay – concentration of pollutant that causes 50% mortality among test organisms Hindrance to marine activities Reduction in quality of sea water

52. © 2011 Pearson Education, Inc. Waste Disposal in Ocean Diluting pollutants with huge volume of ocean water Long-term effects not known Debate about dumping wastes in ocean Some say none at all Some say okay, as long as properly disposed and monitored

53. © 2011 Pearson Education, Inc. Main Types of Marine Pollution Petroleum Sewage sludge DDT and PCBs Mercury Non-point-source pollution and trash

54. © 2011 Pearson Education, Inc. Petroleum Oil spills – often from transport accidents 1989 Exxon Valdez spill in Prince William Sound, AK Smaller-scale spills more common

55. © 2011 Pearson Education, Inc. Petroleum Exxon Valdez spill Many organisms killed outright Long-term consequences unknown

56. © 2011 Pearson Education, Inc. Cleaning Oil Spills Breaks down by natural processes – tar balls sink Skim or absorb oil Bioremediation – using bacteria and fungi to biodegrade oil

57. © 2011 Pearson Education, Inc. Preventing Oil Spills Oil Pollution Act of 1990 Single-hulled tankers barred from U.S. ports, not allowed within 320 km (200 miles) of France and Spain Double-hulled tankers Redesigning ships

58. © 2011 Pearson Education, Inc. Sewage Sludge Semisolid material after treatment Primary treatment Secondary treatment No dumping of sludge in ocean after 1981 Clean Water Act, 1972 Many exceptions/waivers

59. © 2011 Pearson Education, Inc. DDT and PCBs Pesticide DDT Industrial chemicals PCBs (polychlorinated biphenyls) Widespread in oceans Persistent organic pollutants Toxic Long life, dissolved in seawater Accumulated in food chain

60. © 2011 Pearson Education, Inc. Bioaccumulation and Biomagnification Bioaccumulation – organisms concentrate pollutant from seawater Biomagnification – organisms gain more pollutant by eating other contaminated organisms Safe levels of mercury determined by Rate of fish consumption by people Mercury concentration in fish consumed Minimum ingestion rate of mercury to cause damages

61. © 2011 Pearson Education, Inc. DDT Decline in bird populations Thin eggshells Long Island osprey California brown pelican DDT banned in United States in 1972 Rebound of some marine bird populations

62. © 2011 Pearson Education, Inc. Mercury Accumulations

63. © 2011 Pearson Education, Inc. Ocean Dumping Law

64. © 2011 Pearson Education, Inc. Plastics Vast majority of marine debris 80% of marine debris from land sources Most of it plastic Not readily biodegradable Entangle fish, marine mammals, and birds Plastic bags choke turtles Mistake for jellyfish Some plastics attract poisons, e.g., DDT, PCBs

65. © 2011 Pearson Education, Inc. Effects of Plastic Marine Trash

66. © 2011 Pearson Education, Inc. Plastics in the Ocean Floating plastics photodegrade Break into smaller pieces Marine plastic particles increasing significantly Regions of floating trash Eastern Pacific Garbage Patch

67. © 2011 Pearson Education, Inc. Laws Regarding Ocean Dumping In 1988 MARPOL: Proposed treaty banning disposal of plastics Regulating other trash dumping at sea 122 nations ratified by 2005 Facilities not available for garbage disposal

70. Mud Flats

71. A Mangrove Swamp

72. Coral Reefs

73. Scientists divide the ocean into two zones: benthic zone pelagic zone

74. Photic Zone Photic Zone is the top layer, nearest the surface of the ocean and is also called the sunlight layer. In this zone enough light penetrates the water to allow photosynthesis.

75. photic zone Disphotic Zone The Disphotic Zone is found just below the Photic Zone and is known as the twilight layer. In this zone only a small amount of light penetrates the water. Plants do not grow here due to the insufficient amount of light.

76. photic zone disphotic zone Aphotic Zone The darkness layer or Aphotic Zone is entirely dark meaning there is no light. About 90% of the ocean is in this layer.

77. The whale shark, like most marine organisms, is typically found in the sunlight layer or photic zone of the open ocean layers.

78. Animals that live in the disphotic zone, like many types of squid, are adapted to life in near darkness, cold water, and high pressure.

79. Animals that thrive in the aphotic zone are used to living without light!

81. Challenges of Living In the Sea Habitat- environment where organism lives Types of Habitats 1. Planktonic