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Ocean water & ocean life

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Presentation on theme: "Ocean water & ocean life"— Presentation transcript:

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

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

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