lecture 8 – intertidal - zonation physical factors
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Lecture 8 – INTERTIDAL - ZONATION PHYSICAL FACTORS. Studies of intertidal ecology. Descriptive phase. Understand process. Understand interactions. Investigate physiological/genetic/cellular mechanisms. Studies of intertidal ecology. Effects of physical factors. Organism A. - PowerPoint PPT PresentationTRANSCRIPT
Lecture 8 –INTERTIDAL - ZONATION
PHYSICAL FACTORS
Studies of intertidal ecology
Descriptive phase
Understand process
Understand interactions
Investigate physiological/genetic/cellular mechanisms
Studies of intertidal ecology
Organism A
Distribution on the intertidal
Effects of physical factors
Organism B
Distribution on the intertidal
Effects of physical factors
Immersion time
Emersion time
Temperature & desiccation
Wave action
Physical Factors on the Intertidal
1. Desiccation
Barnacle cyprids
Foster 1971. Mar. Biol. 8: 12-29
Time (hours)0 3 6 9 12 15 18
Percentage
100
50
0
mortality
water loss
1. Desiccation
Foster 1971. Mar. Biol. 8: 12-29
Median lethal time (hours)
0 20 40 60 80 100 120 140
Basal diameter (mm)
12
10
8
6
4
2
0
Balanus crenatus
Semibalanus balanoides
Elminius modestus
Why are larger animals more resistant to desiccation?
1 cm
1 cm
1 cm
Surface area = 6 cm2
Volume = 1 cm3
2 cm
2 cm
2 cm
Surface area = 24 cm2
Volume = 8 cm3
Ratio = 6:1
Ratio = 3:1
1. DESICCATION
A second kind of experiment (Foster ‘71, J. Anim. Ecol. 40:33)
1. DESICCATION
A second kind of experiment (Foster ‘71, J. Anim. Ecol. 40:33)
1. DESICCATION
Avoiding drying-seeking refuge (Kensler, 1967, Carefoot, 1977)
Inner Region
Middle Region
Outer Region
Transient species
Highest diversity
Very few inhabitants
Clay, fine silt, sand
Gravel, shells, coarse sand
1. DESICCATION
Avoiding drying
1. Barnacles - trap water CO2
O2
2. Mussels - Airgape
- open valves repeatedly during low tide
1. DESICCATION
Coping with oxygen depletion
Fucus resubmerge
Percentage of initial water retained
Percentage of initial water lost
O2 consump-tion
100
50
100
2. TEMPERATURE
2. TEMPERATURE
2. TEMPERATURE
METABOLIC RATE
ºC
INTERTIDAL INVERTEBRATES
DEEPER WATER INVERTEBRATES
2. TEMPERATURE
Upper Lethal Temperature
Median lethal time (hrs)
40
35
30
Balanus crenatusS. balanoides
Chthalamus
1 2 5 10 20 50
2. TEMPERATURE
Upper Lethal Temperature
Median lethal time (mins)
45
40
35
30
50 100
Asterias
Ophioderma
Arbacia
Uca
Ilyanasa
2. TEMPERATURE-effects of substrate and crowding
TISSUE ºC
EXPOSURE TIME
solitary cobble
crowded cobble
solitary boulder
crowded boulder
solitary cobble
crowded cobblesolitary boulder
crowded boulder
High intertidal
Low intertidal
2. TEMPERATURE-effects of shading
Surface ºC
TIME
40
10
Canopy removed
Under canopy
2. TEMPERATURELatitudinal effects
Helmuth et al, Ecol. Monogr. 2006
2. TEMPERATURE
Tolerances within genera
LT50
45
40
35
30
25
20
• • •••••••• ••
•• •
P. eriomerus
P. cinctipes
10 20 30 40 50
LT50 = MHT
19 species of Petrolisthes
•
Mean Habitat Temperature (MHT)Somero. 2002. Int.Comp. Biol. 42:780
P. cinctipes
P. eriomerus
2. TEMPERATURE
Tolerances within genera
Somero. 2002. Int.Comp. Biol. 42:780
T. funebralis T. brunnea T. montereyi
L. sctulata L. keenae
Temperature and Aggregation
Chapperon & Seuront. 2012. J. Therm. Biol 37: 640
Temperature and Aggregation
Chapperon & Seuront. 2012. J. Therm. Biol 37: 640
Temperature and Aggregation
Chapperon & Seuront. 2012. J. Therm. Biol 37: 640
Desiccation and Aggregation
Coleman 2010. J.Exp.Mar.Biol.Ecol. 386:113
No significant differences
Coleman 2010. J.Exp.Mar.Biol.Ecol. 386:113
Desiccation and Aggregation
No significant differences
2. TEMPERATURE-low temperature
2. TEMPERATURE-low temperature
Dendronotus frondosus(Gionet & Aiken, 1992)
%Survivorship
Temperature (4 hr exposure)
0 -4 -8 -10 -12
100
50
0
3. WAVE STRESS
a. Limitation of size
Water flow100%
90%
Boundary layer
3. WAVE STRESS
a. Limitation of size
Water flow
3. WAVE STRESS
b. Holding on
Keyhole limpet
3. WAVE STRESS
b. Holding on - body orientation
Water flow
3. WAVE STRESS
b. Holding on - body orientation
<.5 m/s
-90 0 90 -90 0 90
>.5 m/s
Freq
Orientation (º to flow)
3. WAVE STRESS
b. Holding on - tenacity
What is “tenacity”?
1. Suction?
Atmospheric pressure ≈ 1 kg/cm2
Patella ≈ 5 - 7 kg/cm2
3. WAVE STRESS
b. Holding on - tenacity
What is “tenacity”?
Patella
3. WAVE STRESS
b. Holding on - tenacity
What is “tenacity”?
2. Adhesion
F = 2 A Sd
area
surface tension
thickness
Theoretical adhesion = 600 kg/cm2
3. WAVE STRESS
b. Holding on - tenacity
What is “tenacity”?
2. AdhesionF 1
d
Tenacity(kg/cm2 to detach)
Weight of mucous
3. WAVE STRESS
a. Limitation of size- plants
Laminaria
3. WAVE STRESS
- How plants deal with it
currentMovement of plant – dissipates E
Reaction force
Inertial force
3. WAVE STRESS
-can extend intertidal zones
Upper limit of barnacles
Upper limit of mussels
Upper limit of fucoids
Upper limit of kelpELWS
EHWS
Exposed Sheltered
Effects on limpet distributionTodgham et al, 1997
Effects on limpet distributionTodgham et al, 1997
HYPOTHESES
1. Greater density of limpets the wave-exposed site.
2. Limpets will be found more frequently in habitats with refuges.
3. Limpets will be found less frequently in wave protected habitats with refuges.
Effects on limpet distributionTodgham et al, 1997
Habitats
Exposed Protected
Effects on limpet distributionTodgham et al, 1997
Wave Velocity Recorder
Effects on limpet distributionTodgham et al, 1997
Lottia digitalis Lottia paradigitalis Lottia pelta
Tectura personna Tectura scutum
Effects on limpet distributionTodgham et al, 1997
At each site recorded:
1. Species
2. Size class - Small, Medium, Large
3. Microhabitata. Bare rockb. Bare rock with barnacles (Balanus)c. On/under algaed. Crevices
Effects on limpet distributionTodgham et al, 1997
Species Protected Exposed P-value
Lottia digitalis
50 ± 7.3 62.4 ± 6.44 NS
L. paradigitalis
18.6 ± 3.7 28.0 ± 2.7 NS
L. pelta 19.6 ± 3.33 18.7± 1.44 NS
Tectura scutum
25.4 ± 3.11 33.9 ± 2.88 0.009
T. personna 25.9 ± 3.8 Not found XXXX
Effects on limpet distributionTodgham et al, 1997
Low tideHigh tide
L. digitalis
L. paradigitalis
L. pelta
T. personna
T. scutum
Effects on limpet distributionTodgham et al, 1997
Wave protected
L. digitalis frequency
Habitat frequency
Bare rock
Rock/Barnacle
Cover
Crevice
Bare rock
Rock/Barnacle
Cover
Crevice
Wave exposed
Lottia digitalis
Effects on limpet distributionTodgham et al, 1997
Distribution of size classes in all species
Effects on limpet distributionBlanchette, 1997
Growth and survival of Fucus gardneri
Effects on Fucus Blanchette, 1997
Growth and survival of Fucus gardneri
Growth and survival of Fucus gardneri
Effects on Fucus Blanchette, 1997
Growth and survival of Fucus gardneri
Effects on Fucus Blanchette, 1997
Growth and survival of Fucus gardneri
March August February
Planiform area m2
Exposed
Protected
Effects on Fucus Blanchette, 1997
Growth and survival of Fucus gardneri
March August February
Mean Length
Exposed
Protected
Effects on Fucus Blanchette, 1997
Growth and survival of Fucus gardneri
March August February
Mean Mass
Exposed
Protected
Effects on Fucus Blanchette, 1997
Transplants
Effects on Fucus Blanchette, 1997
Transplants
P to PP to E
E to PE to E
P to PP to E E to P
E to E
Mean area
Maximum area
Mean area
Sept Sept
Effects on Fucus Blanchette, 1997
Transplants P to PP to E
E to PE to E
Reproductive Status(number of blades with
mature receptacles)
Effects on Fucus Blanchette, 1997
Next time
Intertidal Zonation - Biological Factors