1. Ocean water & ocean life

2. Salinity Total amount of solid material dissolved in water
Ratio of the mass of dissolved substance to the mass of the water sample
Use parts per thousand because proportion of dissolved substance is small number
Average salinity of ocean water is 3.5% or 35 parts per thousand
Salinity

3. Sources of sea salts Where does the salt come from?
Chemical weathering of rocks on continents
Earth’s interior volcanic eruptions emit water vapor & gases over the course of Earth’s history. Elements that make up salts also emitted
Sources of sea salts

4. Processes affecting salinity
Oceans are well mixed
Relative concentrations are fairly constant around
the world
33ppt to 38ppt
Processes affecting salinity

5. Processes affecting salinity
Add large amounts of fresh water to seawater decrease salinity
Precipitation
Runoff from land
Icebergs melting
Sea ice melting
Remove large amounts of fresh water increase salinity
Evaporation
Formation of sea ice
Processes affecting salinity

6. Ocean temperature variation
Surface temperature varies depending on solar radiation
What pattern do you think you would find if you lowered a thermometer from the surface into deeper waters?
Thermocline layer of ocean water between 300m to 1000m
where there is a rapid change in temperature with depth
Ocean temperature variation

7. Ocean density variation
Salinity increase salinity, increase density
Temperature increase temperature results in decrease in density
Which has a greater impact on ocean density and why?
Ocean density variation

8. Density variation with depth
Pycnocline what is it?
Density variation with depth

9. Layers according to density
Surface zone solar energy creates warmer waters, well mixed because of waves and currents
Transition zone thermocline & pycnocline
Deep zone sunlight never reaches, water temperatures are low, density is high
Layers according to density

10. Ocean life! Classified according to where they live & how they move
Plankton
Nekton
Benthos
Ocean life!

11. plankton Organisms that drift with ocean currents
Algae, animals, & plants
Phytoplankton & zooplankton…what’s the difference?
Phytoplankton=plants
Zooplankton=animals
plankton

12. Move independently of ocean currents
Nekton

13. benthos Live on or in the ocean bottom Hydrothermal vents
Super-heated & saturated with minerals
Hot water comes in contact with cold minerals precipitate out
Support organisms not found anywhere else in the world
Chemicals are food for bacteria create sugars and other foods other animals live off of these
benthos

14. Marine life zonessunlight
Photic zone sunlight penetrates upper part of ocean
Euphotic zone part of photic zone where light is strong enough for photosynthesis
Aphotic zone no sunlight available
Marine life zonessunlight

15. Marine life zones distance from shore
Intertidal zone alternately covered and uncovered by seawater with each tidal change
Neritic zone covers continental shelf, often shallow enough for sunlight to reach the floor, entirely within photic zone, 90% of words fisheries
Oceanic zone open ocean, lower nutrient concentration, smaller populations
Marine life zones distance from shore

16. Marine life zones water depth
Pelagic open ocean of any depth
Benthic zone sea-bottom surface
Abyssal zone subdivision of benthic zone, deep-ocean floor, abyssal plains, high water pressure, sparse life, food “rains” down for organisms living on the bottom
Marine life zones water depth

17. Try to sketch a picture that models all of the zones that we discussed 

18. It should look a little something like this 

19. Some sea critters & their homes

20. Productivity in polar oceans
3 months of little to no light during winter
3 months of all light during summer
Why is there an increase in zooplankton right after?
Why does May show the height of phytoplankton (diatoms)?
Feed on phytoplankton. If there is a lot of food, there is higher productivity!
Most sunlight penetrating water= a lot of photosynthesis
Productivity in polar oceans
What is the limiting factor for phytoplankton?

21. Productivity in tropical oceans
Enough sunlight for much photosynthesis
What is the limiting factor in the tropics?
Why might productivity be low?
Permanent thermocline prevents mixing
Supply of nutrients considered biological desert
Barrier between surface waters and nutrient rich deeper waters
Productivity in tropical oceans

22. Productivity in temperate oceans
Winter productivity=low, solar energy is limited
Spring sun is higher=more photosynthesis, spring bloom of phytoplankton, limited by lack of nutrients because depleted very quickly
Summer strong thermocline so limited mixture, nutrients depleted from surface waters and cannot be replaced by deeper waters
Fall summer thermocline breaks down, nutrients return to surface layer, waters mix, sunlight becomes limiting factor
Productivity in temperate oceans

23. Ocean food chains Trophic levels feeding stages
Algae zooplankton & larger herbivores carnivores larger carnivores
Energy transfer about 2% of the energy is transferred
Ocean food chains

24. Beginning of ocean assessment questions 
Approximately what percentage of Earth’s surface is covered by oceans? 40 60 50 70
Beginning of ocean assessment questions 

25. Which ocean basin is the largest?
Atlantic
Pacific
Indian
Arctic

26. The use of sound waves to determine the depth of the ocean is called
Submarine sounding
Sonar
Satellite altimetry
Submersible sounding

27. Bathymetry is Depth of ocean Distance from coast
Only focused on marine life
None of the above

28. The gently sloping submerged surface that extends from the shoreline toward the ocean basin floor is the continental
Shelf
Rise
Slope
Margin

29. Submarine canyons are believed to have been created by
Rivers during the ice age
Earthquakes
Lost ships
Subduction

30. Calcareous ooze is an example of
Terrigenous sediment
Biogenous sediment
Hydrogenous sediment
A combination of hydrogenous and terrigenous sediment

31. Sediments that consist of mineral grains that were eroded from continental rocks are called
Terrigenous
Biogenous
Hydrogenous
Hydrates

32. What could gas hydrates be used for
Landfill
To make concrete
Source of energy
Source of cobalt & copper

33. The most abundant salt in seawater is
Calcium chloride
Sodium chloride
Magnesium chloride
Sodium fluoride

34. Which process does NOT lead to a decrease in salinity of seawater?
Runoff from land
Precipitation
Evaporation
Sea ice melting

35. Which term refers to the layer of water in which there is a rapid change of temperature with depth in the ocean?
Pycnocline
Abyssal zone
Thermocline
Isothermal line

36. Which is NOT a zone in the 3 layered structure of the ocean according to density?
Mixed zone
Deep zone
Transition zone
Intertidal zone

37. Organisms that drift with ocean currents are
Nekton
Plankton
Neritic
Pelagic

38. Which term describes the upper part of the ocean into which sunlight penetrates?
Neritic zone
Intertidal zone
Oceanic zone
Photic zone

39. Phytoplankton are usually found in the
benthic zone
Photic zone
Abyssal zone
Aphotic zone

40. The use of light energy by organisms to convert water and carbon dioxide into organic molecules is
Chemosynthesis
Decomposition
Photosynthesis
consumption

41. During which season does primary productivity reach its peak in polar oceans
Spring
Summer
Fall
Winter

42. In temperate oceans, primary productivity is limited by
Nutrients and oxygen concentration
Nutrients and water temperature
Sunlight and oxygen concentration
Sunlight and nutrients

43. Why is salinity expressed in parts per thousand instead of percent?
Parts per thousand expresses smaller units of measurements

44. Explain how salinity of water in polar regions varies seasonally
During winter sea ice forms & salinity increases because fresh water is pulled out to form ice. During summer sea ice melts and puts fresh water back into the ocean

45. Compare & contrast phytoplankton & zooplankton.
Both drift with waves & currents, limited mobility to vertical motions, phytoplankton are plants zooplankton are animals

46. What factors may affect the depth of the photic zone in any given area of the ocean?
How deep the sunlight penetrates