marine biology

1. ASSIGNMENT PRESENTATION OF MARINE BIOLOGY
TOPIC- Environmental factors
affecting life in the oceans
oxygen & carbon dioxide

2. WHAT ARE ENVIRONMENTAL FACTORS?
• Environmental factors or ecological factors is any
biotic or biotic, that influences living organisms.
• Biotic factors include ambient temperature , amount
of sunlight & pH of the water soil in which an
organism live.
• Biotic factors would include the availability of food
organisms and the presence of nonspecific,
competitors & predators.

3. OXYGEN

4. SIGNIFICANCE
• Oxygen is an important factor which affects life in
aquatic organism.
• Oxygen molecules are present in the form of
dissolved oxygen in oceans.
• Dissolved oxygen refers to the level of free non-
compound oxygen present in water.
• A dissolved oxygen level that is too high or too low
can affect water quality.

5. DISSOLVED OXYGEN & AQUATIC LIFE
• Dissolved oxygen is necessary to many forms of life
including fish, invertebrates, bacteria & plants.
• FISHES & INVERTEBRATES : They require oxygen for
respiration & they respire through gills.
• The amount of dissolved oxygen varies from creature
to creature.

6. • Bottom feeders , crabs, oysters & worms need
minimal amounts of oxygen i.e. 1- mgl.
• Shallow water fishes need higher levels. i.e. 4-15
mgl.

7. • MICROBES & BACTERIA : These organisms use
DO to decompose organic material at bottom of a
body of water .
It plays an important role in nutrient cycling.
• PLANTS & PHYTOPLANKTONS : They require
oxygen for respiration when there is no light for
photosynthesis.
• Plays an important role for the production of
biomass.

8. WHERE DOES DO COMES FROM?
• AIR
• BYPRODUCT OF PLANTS
• PHOTOSYNTHESIS

9. WHAT AFFECTS OXYGEN SOLUBILITY?
• TEMPERATURE-
• The solubility of oxygen decreases as
temperature increases.
• SALINITY
• As salt level increases dissolved oxygen
decreases.

10. CARBON

11. SIGNIFICANCE
• The ocean plays a vital dominant role in the Earth’s
carbon cycle.
• The total amount of carbon in the ocean is about 50
times greater than the amount in the atmosphere.
• At least half of the oxygen we breathe comes from
the photosynthesis of marine plants.
• Currently, 48% of the carbon emitted to the
atmosphere by fossil fuel burning is sequestered into
the ocean.

12. CARBON CYCLE
• Carbon atoms are constantly being cycled through
the earth’s ocean by a number of physical &
biological processes.
• The flux of carbon dioxide between the atmosphere
& the ocean is a function of surface mixing.
• Both physical & chemical processes in the ocean
affects carbon cycle.
• Physical processes influence the net production of
biological oceanography.

13. CARBON CYCLE

14. THANK YOU