MARINE HABITATS

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MARINE HABITATS ROCKY SUBTIDAL
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ZONATION
littoral
infralittoral fringe
CHART DATUM
Infralittoral
Adequate light for photosynthesis
Circalittoral
About 200 m
Infralittoral Circalittoral subtidal
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Substrate Types
Cobble
Walls
Sandy
Horizontal bedrock
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ZONATION
littoral
infralittoral fringe
CHART DATUM
Laminaria forest foliose algae few animals
Upper infralittoral
Foliose algae few animals
Lower infralittoral
Few foliose algae many animals
Upper circalittoral
No algae many animals
Lower circalittoral
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Rocky Subtidal - Zones
1) Sublittoral fringe
Laminaria
Anemone (Metridium)
Bryozoan
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Rocky Subtidal - Zones
2) Infralittoral
Laminaria
Anemone (Metridium)
Urchin barrens
Strongylocentrotus droebachiensis
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Rocky Subtidal - Zones
3) Circalittoral
Sea stars
Anemone (Metridium)
tunicates
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Determinants of Zonation Slope
Horizontal Vertical
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Determinants of Zonation Slope
Depth Emergence
Sponges
Brachiopods
Cover
Density
33 m
42 m
28 m
45 m
Depth
Depth
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Local Processes Affecting the Community
Temperature
Maine
Galapagos
11 12 13
19 23 25
0 5 10 15 20 25 30
0 5 10 15 20 25 30
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Physical Disturbance
Low
High
Depth
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Physical Disturbance
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Physical Disturbance
Creation of Patches
Type I Disturbance -death of some
residents -patch surrounded by survivors
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Physical Disturbance
Creation of Patches
Type I Disturbance -death of some
residents -patch surrounded by survivors
Type II Disturbance -widespread destruction
Recovery - vegetative growth asexual budding
Recovery - long distance dispersers -more
stochastic
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Physical Disturbance
Creation of Patches
Wittman (98)
Predation by nudibranchs
Patch of anemones
Got Type I patches
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Physical Disturbance
Creation of Patches
Wittman (98)
Expect
Got
Recruitment of planktonic bryozoans, polychaetes
and ascidians
Asexual/vegetative growth of neighbours
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Physical Disturbance
Flow Patterns
cm/s
20 40 60 80 100 120 140
2 4 6 8 10
Minium Maximum
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Physical Disturbance
Sedimentation
Sedimentation rate 1/flow
0 5 10 15 20 25 30
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Light
Turbid coastal water
0 5 10 15 20 25 30 35 40 45 50
Depth
Clear open ocean water
Limit for foliose algae
Limit for Laminaria
.01 .1 1 10 100
Percent surface light
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Rocky Subtidal - communities
Terebratulina septentrionalis
Chiton
Terebratulina septentrionalis Community
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Rocky Subtidal - Communities
Terebratulina septentrionalis
Chiton
Crustose coralline algae Community
Bryozoans
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Rocky Subtidal - Biotic Factors
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Biotic Factors on the Subtidal
Predictions
1. Predation - reduced in harsh environments
2. Biotic factors set lower distribution limits
3. Physical factors set upper distribution limits
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Biotic Factors on the Subtidal
1. Predation - reduced in harsh environments
Predator pressure
Predator density
Low High
5 0 5 10 15 20
Galapagos
Seychelles
Gulf of Maine
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Biotic Factors on the Subtidal
1. Predation - reduced in harsh environments
Birds
Crabs/lobster
Impact of predator on prey
Snails/urchins/seastars
minutes
hours
days
Return time of limiting stress
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Biotic Factors on the Subtidal
1. Predation - reduced in harsh environments
New Zealand
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Biotic Factors on the Subtidal
1. Predation - reduced in harsh environments
New Zealand
freshwater
mussels
urchins, sea stars, lobsters
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Biotic Factors on the Subtidal
Predictions
v
1. Predation - reduced in harsh environments
2. Biotic factors set lower distribution limits
3. Physical factors set upper distribution limits
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Biotic Factors on the Subtidal
Predictions
1. Predation - reduced in harsh environments
2. Biotic factors set lower distribution limits
3. Physical factors set upper distribution limits
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Biotic Factors on the Subtidal
2. Biotic factors set lower distribution limits
Anderson Ledges, New Hampshire
Laminaria - limit dictated by urchin grazing
Urchins - stay near bottom of Laminaria -
physical stress too high to go shoreward
Mytilus - colonized areas grazed by urchins
Sea stars - prevent Mytilus recruitment lower in
subtidal
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Biotic Factors on the Subtidal
2. Biotic factors set lower distribution limits
Turbid coastal water
0 5 10 15 20 25 30 35 40 45 50
Light
Depth
Clear open ocean water
Limit for foliose algae
Limit for Laminaria
.01 .1 1 10 100
Percent surface light
32
Biotic Factors on the Subtidal
Predictions
1. Predation - reduced in harsh environments
2. Biotic factors set lower distribution limits
??
3. Physical factors set upper distribution limits
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Biotic Factors on the Subtidal
2. Competition
Competition for space (among algae)
a. allelopathy
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Biotic Factors on the Subtidal
2. Competition
Competition for space (among algae)
b. overgrowth
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Biotic Factors on the Subtidal
2. Competition
Competition for space (among algae)
c. overtopping
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Biotic Factors on the Subtidal
2. Competition
Competition for space (among algae)
d. Aggression (Cnidaria)
acrorhagi
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Biotic Factors on the Subtidal
2. Competition
Competition for space (among algae)
e. Algal whiplash
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Biotic Factors on the Subtidal
2. Competition
Competition for space
Low High
5 0 5 10 15 20
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Biotic Factors on the Subtidal
3. Recruitment
space covered
Low High
5 0 5 10 15 20