1. Life in the Ocean
Pt. 2

2. Used to link nucleic acids Used in molecules that carry energy
Phosphorus
Used to link nucleic acids
Used in molecules that carry energy
Calcium phosphate -> formation of bones, teeth, & some shells

3. Silica
Marine organisms – including diatoms & radiolarians – make skeletons from silica (silicon dioxide)

4. Both cycles are simple:
Phosphorus & Silica
Both cycles are simple:
Taken from rivers & precipitation and taken up by organisms near ocean’s surface.

5. Image Source: http://upload. wikimedia

6. Image source: http://www2. plymouth. ac

7. Phosphorus & Silica
Phosphorus -> released in organic form when organisms decompose Silica in shells -> released back to the water when organisms die – available to be reused back to the environment

8. Factors Affecting Marine Life
Physical factors: any aspect of the physical environment that affects living organisms.
Conditions are usually milder & less variable
Biological factors: biologically generated aspects of the environment.

9. Physical Factor: Light
Photosynthesis may occur below sea surface Sunlight coming in at a low angle reflects off the surface

10. Physical Factor: Light
Selectively absorbed:
Blue light travels further
Red light is absorbed at the surface
Light absorbed by water becomes heat

11. Physical Factor: Light
Depth light travels depends on number & characteristics of particles:
Scatter & absorb light
High concentration quickly absorb most blue & ultraviolet light
Add the reflection of green light by chlorophyll in producers -> changes color of productive coastal waters to green.

12. Physical Factor: Light
Photic Zone: uppermost layer lit by sun
Coastal regions: 330 ft
Mid-latitude: 500 ft
Record: 1,935 ft -> tropical pacific
Photosynthesis occurs slowly at levels with little light

13. Physical Factor: Light
Aphotic zone: permanently dark layer; extends down to seabed

14. Physical Factor: Light
Euphotic Zone: upper part of photic zone where most of the biological productivity occurs
Generally 230 ft – mid-latitudes
Water in this zone accounts for ~1% of all seawater volume, yet nearly all marine life depends on it

15. Physical Factor: Light
Disphotic zone: STILL in photic zone; photosynthesis is difficult