1. IV. Contribution of larval behavior to vertical zonation patterns
A) Processes affecting zonation  4 possibilities
1) Larvae may be stratified in water column (behavior or hydrodynamic effects) and land at different tidal heights
Adult pattern (zonation): a a a A a A a A a a A a a a A a A a b B B b b b B B b B B b b b b b b b b

2. IV. Contribution of larval behavior to vertical zonation patterns
A) Processes affecting zonation  4 possibilities
2) Larvae may  (1) be mixed in water column, (2) exhibit settlement behavior (3) settle within appropriate zone
Adult pattern (zonation): a a a A a b b A a a A b A a a a A A a b b a b B B b a b B B b a B B b b b b b a

3. IV. Contribution of larval behavior to vertical zonation patterns
A) Processes affecting zonation  4 possibilities
3) larvae may (1) be mixed in water column, (2) show no settlement behavior (3) settle randomly and (4) die back to appropriate zonation (post-settlement processes!)
Adult pattern (zonation): a a a A b b b A a a A b A a a b A A b b a b B B b a a B B b a B a b B b b a

4. IV. Contribution of larval behavior to vertical zonation patterns
A) Processes affecting zonation  4 possibilities
4) Individuals may move after settlement
Adult pattern (zonation): a a a A b b b A a a A b A a a b A A b b a b B B b a a B B b a B a b B b b a

5. IV. Contribution of larval behavior to vertical zonation patterns
B) Stratification of larvae in water column
Grosberg 1982, senior thesis! seminal paper never repeated to my knowledge
a) System: Santa Cruz harbor, 2 species of barnacle on pier pilings
i) Balanus glandula – upper intertidal barnacle
ii) Balanus crenatus –lower intertidal barnacle
Tide height (m)
-1.2
1.8
Adult Density (#/100 cm2)
B. glandula
B. crenatus
100
b) Pattern:

6. B) Stratification of larvae in water column
c) Question: What causes vertical zonation?
d) Hypotheses:
i) HA1: early post-settlement mortality limits species distribution (sensu Connell)
ii) HA2: stratification of larvae limits distribution  via behavior
Tidal
height
e) Test:
2.1
i) HA1 early post-settlement mortality
10 x 10 cm plates
Sampled weekly during a period of high settlement - allows detection of 1–7 day old individuals
-1.2

7. B) Stratification of larvae in water column
Question: What causes vertical zonation?
f) Results:
Settlement pattern…
1.8
Adult pattern…
B. glandula
Adult Density (#/100 cm2)
-1.2
1.8
B. glandula
B. crenatus
100
Tidal
height
-1.2
800
Settler density (#/100cm2)
1.8
B. crenatus
-1.2
1000
Settler density (#/100cm2)

8. B) Stratification of larvae in water column
Question: What causes vertical zonation?
g) Conclusions:
1) settlement was same distribution as adults
2) not post-settlement processes causing adult distribution

9. B) Stratification of larvae in water column
Question: What causes vertical zonation?
ii) HA2: stratification of larvae limits distribution  via behavior
d) Test — clever
i) sampled on 3 days: new, full, half moon — plankton pulls
ii) sampled hourly for 24 hour periods on each day
iii) sampled from a floating dock at 4 depths:
surface, 0.5 m, 1.5 m, and 3 m
sampling range: -4 m to 1.8 m
Time of day
Tidal range sampled
-4.0
1.8
surface 3m
3m depth

10. e) Results — differ between species:
ii) HA2: stratification of larvae limits distribution  via behavior
e) Results — differ between species:
1) 94% of glandula larvae taken in surface waters (irrespective of tidal sequence)
2) 98% of crenatus larvae were collected < 0 m mllw, (meaning their distribution in water column changed as a function of tide
B. glandula
B. crenatus
Larval abundance
-4.0
1.8
-4.0
1.8
1.8
surface
Tidal range sampled
B. glandula
B. crenatus
-4.0
Time of day

11. Larval Distribution in water column corresponds to settler and adult distribution on pilings
Settlers
Adults
Larvae
1.8
1.8
surface
B. glandula
Tidal range sampled
Tidal height
B. crenatus
-4.0
-4.0
Time of day

12. ii) HA2: stratification of larvae limits distribution  via behavior
f) Conclusions-
1) Distribution of adults determined by position of larvae in water column
2) Larval distribution set by two different behaviors:
a) B. glandula stays in surface water, which over tidal sequences travels from about -1.2 to 1.8 m (abundances correspond to time at tidal height)
b) B. crenatus stays below a particular tidal level  orients to bottom?

13. C) Interactive effects of vertical distribution of larvae and biogenic structure on the spatial and temporal patterns of recruitment
Example: Carr Ecology
a) Question: Does kelp provide settlement habitat for reef fishes, and if so, does the temporal and spatial variability of kelp influence patterns of fish recruitment?
b) System: Forests of giant kelp, Macrocystis pyrifera and the kelp bass, Paralabrax clathratus at Santa Catalina Island, CA

14. and test of first hypothesis:
c) Hypothesis 1: If giant kelp influences recruitment, there will be a positive relationship between abundance of kelp and kelp bass recruits
within reefs…
d) Pattern:
P <
and test of first hypothesis: 30 20
Density of kelp bass recruits
(No. per 60 m3 )
Greater density of kelp bass settlers in areas of a reef with giant kelp compared to areas without 10
Absent
Present
Macrocystis

15. d) Pattern: among reefs and years…10 20 30
100
200
300
400 1 2 3 5
Macrocystis density
(Stipes per 30 m2)
kelp bass recruit density
(Number per 60 m )
Density of kelp bass settlers increases with increasing density of giant kelp… but it is not linear!

16. c) Hypothesis 2: Local kelp bass recruitment should respond to manipulated density of giant kelp
kelp bass recruit density:
(Number / 10 m ) 2 40 80
120
160 1 3 4 5 A B
kelp bass recruit density:
blade biomass (gm per 5 m3 )
500
1,000
1,500 2 4 6
(Number per 10 m2)
blade biomass per reef area:
Macrocystis density (stipes / 30 m2 ) A B
400
800
1,200
(grams / 10 m ) 2 40 80
120

17. e) Conclusions:
i) Local and “regional” patterns of kelp bass recruitment are influenced by dynamics of giant kelp abundance
ii) The relationship is not based strictly on plant density, but on biomass (shelter!). Because kelp biomass changes with plant density, recruitment relationship is asymptotic.
iii) Giant kelp facilitates recruitment of kelp bass by providing habitat that they encounter as they pass over reefs

18. Settlement (post-settlement): habitat structure
(1) Macrocystis (kelp bass in southern California)
e.g., Carr 1994, Ecology
- manipulated kelp density and monitored recruitment
- greater kelp bass recruitment with increase in kelp
(2) Macrocystis (kelp surfperch in so. California)
e.g., Anderson 1994, MEPS
manipulated presence of giant kelp canopy and monitored recruitment
greater kelp perch recruitment in presence of canopy
(3) Sea urchins (blue-banded goby in southern California)
e.g., Hartney and Grorud 2002, Oecologia
- manipulated presence of urchins and monitored recruitment
e.g., Rogers-Bennet and Pearse 2001, Conserv. Biology
- compared abalone recruitment in and out of MPAs with and without urchins

19. Coastally trapped waves Small-scale fronts, plumes, runoff
Larval settlement
100 yrs
PDO
1 decade
Seagrass
beds
Kelp
forests
ENSO
1 year
Seasonal upwelling
Mesoscale eddies
1 month
Temporal scale
Coastally trapped waves
1 week
Small-scale fronts, plumes, runoff
1 day
Plankton migration
Surface tides
1 hour
Langmuir cells
Internal waves
Turbulent eddies
1 min
Surface waves
1 cm
1 dm
1 m
10 m
100 m
1 km
10 km
100 km
1000 km
10000 km
Linear spatial scales

20. V. (Early) post-settlement processes as sources of variation in recruitment
a) Recall that “recruitment” estimates occur at some point subsequent to settlement
b) Do post-settlement processes alter patterns of settlement and recruitment?
c) Can post-settlement processes cause density-dependent mortality that would (de-couple) patterns of settlement and recruitment?
d) How important are competition and predation as sources of variation in recruitment AND density-dependent mortality?

21. Sources of spatial and temporal variation in recruitment
Post-settlement:
- survival
- growth
- movement
competition
predation

22. Early post-settlement: competition
Conspecific and interspecific resident effects
e.g., Steele 1997a, Ecology
- black-eyed and blue-banded gobies in So. CA
- manipulated presence of adults of both
- settlement of black-eyed (-) “influenced” in presence of adult conspecifics
- settlement of black-eyed not influenced by presence of adult blue-banned
- settlement of blue-banded (+) influenced in presence of adult conspecifics
- settlement of blue-banded not influenced in presence of adult black-eyed

23. Sources of spatial and temporal variation in recruitment
Post-settlement:
- survival
- growth
- movement
predation
competition

24. V. (Early) post-settlement processes as sources of variation in recruitment
General approach:
i) To test for predator effects, manipulate presence and absence of predators
ii) To test for density-dependence, manipulate density of settlers
iii) To test for density dependence caused by predation, manipulate BOTH orthogonally

25. Early post-settlement mortality: predation
black eyed goby
1.0
0.8
per-capita
mortality
Steele Oecologia
0.6
0.4
0.2
Note! Predators present!
0.0
kelp
perch 5 10 15
Initial density
kelp rockfish
1.0
Anderson Ecology
1.0
Johnson 2006 Ecology
predators present
predators absent 20 40 60 20 40 60 80
100

26. Conclusions
(1) Post-settlement mortality is a source of variation in recruitment
(2) Predation is an important source of post-settlement mortality
(3) Predation is also a source of density-dependent mortality, which can decouple estimates of settlement and recruitment (think about this with respect to testing for recruitment limitation)

27. VI) Settlement, density dependence and recruitment
How would this occur? if post-settlement processes act in a (complete) density-dependent manner
Density-independent
Density-dependent
survivorship:
50% 2 10
survivorship:
# adults: recruits!
# adults: recruits! 50
30% 2%
100%
100 2 10 5 2 1
100 2 10
100 2 10
100
#settlers
#settlers
#settlers
#settlers
density independence: same probability of surviving regardless of density  direct relationship between settler # and recruit #
density dependence: no relationship between settler # and recruit #