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Abiotic Factors
The Abiotic Factors
1. Geological
-  plate tectonics
-  Shoreline classifications
2. Physical
-  Light
-  Temperature
-  Water movement
3. Chemical
-  Salinity
-  Gases
-  Nutrients
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North
Sea
Gulf of
Alaska
Mediterranean Sea
Gulf of Mexico
Arabian
Sea
Caribbean Sea
Tasman
Sea
Importance of Ocean Coverage
highest elevation
average elevation
average depth
lowest depth
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Geological Factors
late precambrian =
evolution of macroalgae
Permian = cycads, conifers
Triassic = gymnosperms,
fern forests, dinosaurs
Geological
History
and Plant
Development
Jurassic = gymnosperms,
mild climate, inland seas
Cretaceous = angiosperms,
dinosaurs disappear
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Classification of the Coasts
Rocky Shores
consolidated, younger
high energy
cliffs, platforms,
different rock types
= lithophytes
supratidal/splash=
when is it covered? extreme tides, storms, spray
what are the challenges? dessication, temperature
who lives there?
intertidal
=
when is it covered?
high tide
challenges?
dessication, temperature, physical limits
who lives here?
brown algae
tidepools
=
who lives there?invertebrates,
challenges/advantages?
subtidal
=
most stable
Algal representatives=> depends on boulder
size/sand
red and
green deposition
Classification of the Coasts
Beaches
unconsolidated
primary and
secondary
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Classification of the Coasts
Estuaries
younger,
ephemeral
= depositional
fw/sw mix
Geomorphic estuaries = fjords, deltas, drowned river valleys, flat plains
Salinity stratification ranges:5-35 ppt,top freshwater, bottom saltwater
Tidal currents:aestus = tide, depends on size of the opening
=> fluctuation of abiotic factors
Particle Size versus Slope
Particle Size!
Name!
Average Slope!
Gravel!
64-256 mm!
Boulders!
< 24°!
4-64 mm!
Cobbles!
24°!
2-4 mm!
Pebbles!
17°!
1-2 mm!
Granules!
11°!
!
Sand!
0.5-1 mm!
Very course!
9°!
250-500 µm!
Coarse!
7°!
125-250 µm!
Medium!
5°!
62-125 µm!
Fine!
3°!
2-62 µm!
Very fine!
1°!
!
Mud!
> 2-2 µm!
Silt/Clay!
0°!
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Particle Size versus Slope
Rocky Shores
Above 24° angle, clear
zonation
good substrate for
attachment
Gravel Substrate
11-24° angle, some
zonation
attachment possible,
algae, marshgrasses
Particle Size versus Slope
Sandy Beach
1-9° angle, diatoms,
cyanobateria, protists
marshgrasses and
seagrasses
Mudflats
0° angle, diatoms,
cyanobateria, protists
marshgrasses
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Physical factors
Physical Factor: Light
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1m
10m
50m
Within the first 1m 50% of
the light is absorbed. End red
At 10 m depth only about 20%
of light is still visible. End
yellow
End green.
70m
Photosynthesis mainly keeps
organisms alive, no surplus for
growth, repair, reproduction.
100m
Only about 0.5% of light that
falls onto ocean surface will
penetrate to this depth. End
blue.
=> 0.006% light will penetrate down to 200m, 200-1000m not completely dark
Absorption of Light and Light in
the Ocean
Attenuation of daylight in the ocean in % per meter as a function of wavelength in :!
I pure ocean water!
II turbid sub-tropical water!
III mid latitude water!
1-9 coastal waters (increasing turbidity)!
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Physical Factor: Temperature
one of the most fundamental abiotic factors
high temps = protein denaturation, damage to
enzymes and membranes
low temps = disruption of lipids and proteins
(membranes), mechanical damage through
production of ice crystals
Temperatures
with Depth
decrease with depth
mixed layer = stable
temperature & ?
seasonal thermocline
permanent thermocline
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Examples of Geographical Distribution
Laminaria
Laminaria
Laminaria
Mangroves
Mangroves
Mangroves
Mangroves
Laminaria
Laminaria
Laminaria
Laminaria
Mangroves
Laminaria
Temperatures and Climate Change
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