1. Currents, Waves and Properties of Water
Unit 4
Currents, Waves and Properties of Water

2. Water We live on a water planet
Over 70% of the Earth’s surface is covered with water
97% of that is saltwater
If it were not for water and its properties, life on Earth would not be possible

3. Water – Chemical Properties
Formed by covalent bond
1 oxygen and 2 hydrogen atoms
Polar molecule
Positively and negatively charged ends attract each other

4. Properties of Water Chart
Define each of the properties of water
Describe how each property relates to the marine environment

5. Example: Adhesion
The Lumpsucker Fish

6. Properties of Water Continued!

7. pH “Potential of Hydrogen”
A system of classifying how acidic or basic something is

8. pH

9. Acids (0-6)
Substances that release hydrogen ions (H+) when dissolved in water
The more H+ ions released, the more acidic the solution becomes
Reminder:
*Ion – an atom that has gained or lost electrons

10. Bases (8-14)
Substances that release hydroxide ions (OH-) when dissolved in water
The more hydroxide ions a substance releases, the more basic (alkaline) the solution becomes

11. Neutral pH 7 (pure water)
Equal amount of hydrogen ions (H+) and hydroxide ions (OH-)

14. pH and the Ocean pH ranges from 7.5 to 8.2
In saltwater, pH is closely related to dissolved CO2
CO2 is a reactant of photosynthesis and a product of respiration. It dissolves easily in saltwater.
Decreases in pH could result in lowered enzyme activity and could dissolve the shells of marine animals

17. Global Climate Change Causes
Increased CO2 & Methane from burning of fossil fuels
Deforestation
Pollution

18. Global Climate Change Consequences Ocean acidification
Rising sea level
Changing weather patterns
Habitat loss

19. Global Climate Change Solutions Educate Alternative energy
Sustainable practice
Legislation

21. Biogeochemical Cycles
The movement (or cycling) of matter through a system
Matter refers to elements (C, N, O) or molecules (water)
All matter cycles; it is neither created nor destroyed

22. Biogeochemical Cycles Include:
Hydrologic Cycle
Nitrogen Cycle
Oxygen Cycle
Carbon Cycle

23. Dissolved Gases Dissolved Nitrogen Most prevalent
Cannot be used by organisms until it is attached to oxygen in a process called nitrogen fixation
Nitrogen fixation is important because blue-green algae convert nitrogen to a usable form that animals need for building amino acids

25. Dissolved Oxygen Important to the survival of organisms
Too much can be toxic
Comes from marine plants and algae (through photosynthesis); also wave action
Below the thermocline, there is very little oxygen
Thermocline – a thin but distinct layer in which temp changes more rapidly with depth than it does in the layer above or below it

27. Carbon Dioxide Comes from air, respiration Very soluble
More carbon dioxide in the ocean than in the atmosphere (carbon sink)

29. pH is Logarithmic
Each whole number on the pH scale differs by a factor of 10
Example:
A pH of 2 is 10X more acidic than a pH of 3
A pH of 2 is 100X more acidic than a pH of 4, 1000X more acidic than a pH of 5 and 10,000X more acidic than a pH of 6…

31. Effects of Carbon Dioxide on pH
Demonstration
Effects of Carbon Dioxide on pH

32. Acid
Neutral
Base
*Bromethymol Blue pH indicator in an acidic, neutral & basic solution

34. Ocean Acidification
A decrease in ocean pH due to the absorption of CO2 from the atmosphere.

35. 4 Key Concepts The amount of CO2 in the atmosphere is increasing
The chemistry of the ocean depends on the chemistry of the atmosphere
Water becomes more acidic (lower pH) the more CO2 it contains
Increased ocean acidity impacts marine organisms’ abilities to make and keep their shells

36. Cartoon: Ocean Acidification
By the Alliance for Climate Change

37. The Battle for Carbonate
Carbonate ions (CO3) (found naturally in seawater) are used by animals to make shells
When CO2 reacts with seawater, it releases H+ ions
The more H+ ions there are, the more acidic the ocean becomes.
As a result, shelled creatures need to spend their energy making shells instead of finding food

38. Acid Test: The Global Challenge of Ocean Acidification
What are the effects of ocean acidification on the marine environment?

39. Calcium carbonate part
Coral skeleton
Skeleton (test)
Shell
Component of fronds
Calcium carbonate part
Stony coral
Sea urchins
Pteropods
Coralline algae
Fish

40. Effects of Ocean Acidification:
Thinner, smaller and weaker shells in shellfish (especially at the larval stage)
Fitness Effect - Lower survival due to:
Increased crushing & drilling by predators
Increased risk of desiccation at low tide

41. Reduced hearing ability in some fish
Ear bones (otoliths) made of CaCO3
Fitness Effect - Lower survival due to easier predation
Increased photosynthesis & growth for marine algae
Lower pH means more CO2 fuel for growth
Fitness Effect – higher survival and pop growth