1. OCEAN WATER & OCEAN LIFE
Composition of Seawater
Salinity- total amount of solid material
dissolved in water.
* ocean = 35 parts per thousand
Sources of Materials
1. Chemical weathering of rocks
- runs off into rivers, then into oceans
2. Earth’s interior(volcanic eruptions)

2. Ocean Salinity

3. Affects on Salinity
1. Decreasing salinity
- caused by rain and ice melting
2. Increasing salinity
- caused by evaporation & freezing

4. Processes Affecting Salinity

5. Ocean Density
*Density- mass per unit volume
- density causes ocean water to
rise or sink.
Affects on Density
1. Salinity- higher salinity= higher density
lower salinity = lower density
2. Temperature- high temp. = low density
low temp. = high density

6. Ocean Temp. Variation
1. Surface
- ocean’s surface temp. varies with
the amount of sunlight.
2. Deep Water
- temp. decreases from surface to
seafloor.
*thermocline- layer of ocean with
changes in temp. ( m)
- stays around 0 C after 1000m.

7. Thermocline

8. Ocean Density Variation
Density increases from surface to
seafloor.
*pycnocline- layer of ocean with changes
in density.
- separates warm, low density water
from cold, high density water

9. Pycnocline

10. Ocean Layering
*layered by density
1. Surface Mixed Zone
- warmest zone
- affected by waves & currents
2. Transition Zone
- area between warm & cold layers
3. Deep Zone
- no sunlight, coldest layer

11. Ocean Zones

12. Marine Organisms
* classified by where they live.
Types
1. Plankton- organisms that drift with
ocean currents.
2 Groups
A. Phytoplankton
- carry out photosynthesis
B. Zooplankton
- animal-like microogranisms

13. Plankton
Phytoplankton
Zooplankton

14. 2. Nekton
- organisms that can swim throughout
the oceans.
ex.- fish, squid, marine mammals

15. 3. Benthos
- organisms living on the ocean
bottom.
ex. – algae, seaweed, crustaceans

16. Marine Life Zones
* Divided by:
1. Amount of sunlight
2. Distance from shore
3. Water depth
Sunlight
1. Photic Zone- upper layer receiving sun.
2. Aphotic Zone- bottom layer with no sun.

17. Distance from Shore
1. Intertidal Zone
- area where land & water meet.
- affected by the tides
2. Neritic Zone
- area from low tide line to Cont. Shelf.
- nutrient rich
3. Oceanic Zone
- the deep, open ocean
- nutrient poor

18. Depth
1. Pelagic Zone
- open ocean of any depth
2. Benthic Zone
- any sea bottom surface
- shallow or deep
3. Abyssal Zone
- deep ocean floor
- primarily abyssal plains

19. Marine Life Zones

20. OCEAN PRODUCTIVITY
Primary Productivity
- energy created by photosynthesis or
chemosynthesis.
Affected by:
1. Amount of sunlight
2. Amount of nutrients

21. Productivity in Temperate Oceans

22. Feeding Relationships
Food chain- sequence of energy transfer in
a single path.
Food web- complex system of energy
transfer.
*Energy transfer is inefficient
- less energy at top of food chain/web
*Animals in a food web survive better than
animals in a food chain.

23. Food Chain vs. Food Web

24. OCEAN CIRCULATION
Ocean currents
- masses of ocean water moving from one
place to another.
Types
1. Surface Currents
- movements that flow horizontally
- mostly caused by wind
2. Gyres
- large, circular movement of water
- caused by wind & Coriolis Effect

25. Ocean Surface Currents

26. 3. Upwelling
- rising of cold water to the surface
- caused by wind pushing out warm
water
- brings up nutrients
4. Density Current
- vertical current caused by sinking
dense water
CAUSED BY:
1. Decrease in temperature
2. Increase in salinity