1

Chapter 13 Life in the Ocean

Energy – use of energy to sustain life

Ultimate source of energy to planet –sun

1:2000 captured by organisms

Light energy to chemical energy-photosynthesis

Chemosynthesis

Primary Productivity – synthesis of organicmatter from inorganic constituents by photoor chemosynthesis

Primary Consumers – Feed on Primary Producers

2

Diatom - Coscinodiscus

3

C6H12O6 CO2

C6H12O6 + 6H2O 6CO2 + 24H+ + 24 e-

Stored Chemical energy transferred to electron potential

The electron potential then is used to “charge up” ATP

Aerobic organisms

Electron donor - Simple Carbon Compound (Glucose)

Electron acceptor – Oxygen

Glucose molecule makes ~ 30 ATP

Energy is then lost to space, by heat, movementAutotrophs – can make their own food

Heterotrophs – must consume other organisms

4

1 ton of Blue Whale

10 tons of fish

100 tons of small fish

1,000 tons of zooplankton

10,000 tons of phytoplankton

300,000

1966 nearly extinct

Today 8,000

150-170 tons, 27 m

Where does a whale eat on the foodchain ?

?

?

?

Life is composed of 23 of the 107 known elements

C, H, O, N make up 99% of mass of all living things

9 other make up most everything else

Carbohydrates, lipids, proteins, nucleic acids

5

Remarkable amount of recycling, transformations

of elements between living and non living compartments.

Biogeochemistry

Limiting nutrient – how does this limit productivity ?

Carbon is the largest of the cycles

Incorporated for growth 45%

respiration for energy 45%

dissolved organic C 10%

6

Release of C stores, burning fossil fuels – peat miningPeat Mining in Florida –Release of Carbon Stores

Peat Mining in Ireland –Release of Carbon Stores Peat Mining in Ireland –Release of Carbon Stores

7

Peat Mining in the Netherlands –Release of Carbon Stores

Nitrogen Cycle

N2 gas

Nitrogen fixation

Organic N NH4 NO3 N2 gas

Phosphorus and Silica

Organic P, Si

PO4 silicate

ATP, bones, nucleic acids skeletons

8

Three loops for P and Si

Short term – days (in surface waters)

Long term – few hundred years (in deep waters)

Geologic – millions of years (in sediments, rocks)

Physical Factors

Light – autotrophs

Light penetration depends on sun’s angle

Particles

Photic Zone – 100 meters at the coast

150 meters at mid latitude

590 meters- deepest

Euphotic zone – good

Disphotic zone - difficult

1%

Open ocean is blue-green

Coastal ocean is green

Temperature

Depth, latitude

Narrow range

Metabolic rate doubles with each 10 C

Child falls through the ice

Two tanks of fish, one heated, one unheated

Fish in warmer tank will eat more, grow faster,

9

Dissolved Nutrients

16 atoms of N for 1 atom of P

Ocean water has 1/10,000 availability of Nthan soil.

Salinity

Salt balance = water balance for most organisms

Dissolved Gases

CO2 and O2

50 ppt vs 6 ppt ocean has more C than air

Acid – Base Balance

7.5 vs 8.5

High productivity raises pH

Hydrostatic Pressure

Pressure in = pressure outDeep sea trawls

Diffusion – solutesOsmosis - water

Diffusion through a membrane = osmosis

Isotonic

Hypertonic

hypotonic

10

Surface to volume ratio

Surface area increases as the square of the diameter

Volume increases as the cube of the diameter

Classification of the Marine Environment

11

What kingdoms exist in classification of organisms ?

Taxonomy

12