Post on 31-Oct-2019
13 - Marine Ecology
“Bipartite” life cycle of benthic marine fishes with pelagic larvae
Benthic Environment
Adult
Larvae
Juvenile
Pelagic Environment
survive, grow, mature
survive, grow, develop, disperse
settlement reproduce
“Bipartite” life cycle of benthic marine fishes with pelagic larvae
Supply Production
Little or no exchange among
populations
Significant exchange among
populations
Supply Production
Supply Production Supply Production
Decouples local production and supply
“Open” Populations “Closed” Populations
Propagule Duration (hr)
Pelagic duration - a proxy for dispersal potential
0.0001
0.001
0.01
0.1
1
10
100
1000
10000
0.01 0.1 1 10 100 1000 10000
Dis
pers
al D
ista
nce
(km
) invertebrates fish
Predicted by passive dispersal
Shanks et al. 2003 Ecological Applications
Larval duration of 24 coastal fish species from western North America
SPECIES Larval duration midpoint (range)
Shanks et al. 2003 Ecological Applications MEAN = 94 days
0.0001
0.001
0.01
0.1
1
10
100
1000
10000
0.01 0.1 1 10 100 1000 10000
Dis
pers
al D
ista
nce
(km
)
Propagule Duration (hr)
Pelagic-duration
Indirect Estimates of Larval Fish Dispersal Distances
10’s to 100’s of km
= 30 days
“Isolation by distance”
1 m 10 m 100 m 1 km 10 km 100 km 1000 km
Fish
Estimated dispersal scale
0
5
10
Kinlan & Gaines 2003 Ecology
Shanks et al. 2003 Ecological Applications
Palumbi 2003 Ecological Applications
The paradigm shift Generally assumed that larvae disperse away from natal population…
Anemonefish recruitment study - Moorea, French Polynesia
1.Surveys
MantaTowsScubaDiving
2.Characteriza;on
3.DNAmaterial
3.DNAmaterial
3.DNAmaterial
4. Return the fish
4. Return the fish
5.Samplinglocalitydatabase
Location of all Amphiprion chrysopterus collected around Moorea (French Polynesia)
1-10 11-20 >21
individuals
2007 2008
2010
Moorea,PGEM
Harrison et al. 2012
Recruitment studies demonstrate “spillover” effect
Potential consequences of larval dispersal:
• local recruitment (replenishment) not necessarily tied to local production • recruitment critical to replenishment of local
populations • local replenishment reliant on recruitment of larvae
produced elsewhere
• “open” spatial structure of local and regional populations • openness decreases as likelihood that larvae
return to adult population increases
Seagrass beds
Recruitment is important and fascinating…
but its very complex!
1 cm 1000 km 100 km
Linear spatial scales
Tem
pora
l sca
le
1 m 10 m 100 m 1 km 10 km 1 dm
100 yrs
1 month
1 week
1 day
1 hour
1 min
1 year
1 decade
Turbulent eddies Surface waves
Surface tides
Langmuir cells
Plankton migration
Small-scale fronts, plumes,
runoff
Coastally trapped waves
Seasonal upwelling
Mesoscale eddies
ENSO
10000 km
PDO
Internal waves
Internal tides
Coastal filaments, Upwelling / relaxation
Seasonal current shifts
After T. Dickey, unpublished
Kelp forests
1 cm 1000 km 100 km
Linear spatial scales
Tem
pora
l sca
le
1 m 10 m 100 m 1 km 10 km 1 dm
100 yrs
1 month
1 week
1 day
1 hour
1 min
1 year
1 decade
Turbulent eddies Surface waves
Surface tides
Langmuir cells
Plankton migration
Small-scale fronts, plumes,
runoff
Coastally trapped waves
Seasonal upwelling
Mesoscale eddies
ENSO
10000 km
PDO
Internal waves
Internal tides
Coastal filaments, Upwelling / relaxation
Seasonal current shifts
After T. Dickey, unpublished
Kelp forests
Larval production Seagrass beds
Recruitment is important and fascinating…
but its very complex!
Seagrass beds
1 cm 1000 km 100 km
Linear spatial scales
Tem
pora
l sca
le
1 m 10 m 100 m 1 km 10 km 1 dm
100 yrs
1 month
1 week
1 day
1 hour
1 min
1 year
1 decade
Turbulent eddies Surface waves
Surface tides
Langmuir cells
Plankton migration
Small-scale fronts, plumes,
runoff
Coastally trapped waves
Seasonal upwelling
Mesoscale eddies
ENSO
10000 km
Internal waves
Internal tides
Coastal filaments, Upwelling / relaxation
Seasonal current shifts
After T. Dickey, unpublished
Kelp forests
Larval dispersal, mortality
PDO
Recruitment is important and fascinating…
but its very complex!
Seagrass beds
1 cm 1000 km 100 km
Linear spatial scales
Tem
pora
l sca
le
1 m 10 m 100 m 1 km 10 km 1 dm
100 yrs
1 month
1 week
1 day
1 hour
1 min
1 year
1 decade
Turbulent eddies Surface waves
Surface tides
Langmuir cells
Plankton migration
Small-scale fronts, plumes,
runoff
Coastally trapped waves
Seasonal upwelling
Mesoscale eddies
ENSO
10000 km
PDO
Internal waves
Internal tides
Coastal filaments, Upwelling / relaxation
Seasonal current shifts
After T. Dickey, unpublished
Kelp forests
Larval settlement
Recruitment is important and fascinating…
but its very complex!
Sources of spatial and temporal variation in recruitment
Larval production
Larval dispersal
Settlement
Post-settlement
Sources of spatial and temporal variation in recruitment
Larval production:
- adult abundance
- adult fecundity (eggs per female) size structure / sex ratio adult condition
Offspring production: climatic variability
- Bight-wide patterns of juvenile impingement - declines in recruitment for many spp. (1980 - 1991) - attributed to reduced production (but maybe larval survival) - reflecting large-scale decline in productivity
Power plant studies:
Ocean climate change
Perch recruitment
Population responses (4 species)
Benthic productivity
Surfperch production Holbrook et al. 1997 Ecological Applications
(Love et al. 1998 Fishery Bulletin) (Brooks et al. 2002 Mar. Freshwater Res.)
Sources of spatial and temporal variation in recruitment
Larval dispersal (direction, distance, delivery):
- larval behavior - larval duration
- oceanographic features - interaction among these
Larval production:
- location of reproduction - timing of reproduction
e.g., Norris 1963, Ecological Monographs
Physical processes and larval behavior
(1) Larval cues: (light, pressure, temperature, structure)
- Opaleye (Girella nigricans) - recruitment related to tide pool temp. - lab experiments: thermal preference - coast-wide patterns of recruitment - hypothesized mechanisms of larval delivery:
- internal waves - thermal / structural cues - upwelling
Shanks 1983 Mar. Ecol. Prg. Ser. ONSHORE TRANSPORT
“Structure - schooling” Long larval duration (3 - 4 months)
“Benthic - solitary” Short larval duration (1-2 months)
Black-&-yellow rockfish
Gopher rockfish
Kelp rockfish
Black rockfish
Yellowtail rockfish
Olive rockfish
e.g., Larson et al. 1994, Lenarz et al. 1995, CalCOFI Rpt.s
(2) shifts in vertical distribution with ontogeny -- upwelling
- vertical distribution of early and late larval rockfishes
0 0.2 0.4 0.6
13
37
87-117
proportion
depth (m)
“structure - schooling” spp. “benthic - solitary” spp.
Physical processes and larval distribution
offshore
onshore
depth early
larvae late
larvae
pelagic juveniles
kelp bed
(1998) (1999) (2000) El Nino La Nina La Nada
Mid-water complex Long larval duration (3 - 4 months)
Benthic complex Short larval duration (1-2 months)
Kelp, Black-&-yellow, and Gopher rockfish
Olive, Yellowtail and Black rockfish
100 75 50 25 0
25 50 75
100
Rel
ativ
e A
bund
ance
1986 1992
1.0
0.5
0.5
1.0
0
Prop
ortio
n
Lenarz et al. 1995 CalCOFI
Benthic complex Short larval duration (1-2 months)
Relaxation
(1998) (1999) (2000)
El Niño La Niña
Normal
Fish
per
240
m3
0
4
8
12
16
20 Kelp, Black-&-yellow, and Gopher rockfish
Black-&-yellow rockfish
Gopher rockfish
Kelp rockfish
Mid-water complex Long larval duration (3 - 4 months)
Upwelling
10
30
50
70
(1998) (1999) (2000)
El Niño La Niña
Normal
Fish
per
240
m3
Olive, Yellowtail and Black rockfish
Black rockfish
Olive rockfish
Yellowtail rockfish
Sources of spatial and temporal variation in recruitment
Settlement:
- habitat structure - priority effects
conspecific cues predation
- larval cues
competition
Macrocystis Density (stipes / 30 m ) 2
Kelp Bass Recruit Density
(Num
ber
/ 10
m )
2
Blade Biomass Per
Reef Area
0 100 200 300 400
1
3 5
10 30
0 40 80 120 160 0 1 2 3 4 5
A
B B
0
A
B B
400
800
1,200 (g
ram
s /
10 m
)
2
Settlement (post-settlement): habitat structure
(Num
ber
/ 60
m )
3
0 40 80 120 Carr Ecology 1994
Sources of spatial and temporal variation in recruitment
Settlement:
- habitat structure - priority effects
conspecific cues predation
- larval cues
competition
Not a lot of information!
Sources of spatial and temporal variation in recruitment
Early post-settlement:
- growth - movement
competition predation
- survival
0 20 40 60 80 100
kelp rockfish
0.0 0.2 0.4 0.6
0.8
0 5 10 15
black eyed goby
Initial density
Early post-settlement: predation
per-capita mortality
Anderson 2002 Ecology kelp perch
Steele 1997 Oecologia
Johnson unpublished
predators present predators absent
1.0
1.0 1.0
0 20 40 60
e.g., Steele 1997a, Ecology
Conspecific and interspecific resident effects
- black-eyed and blue-banded gobies in So. California - 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
Early post-settlement: competition
Sources of spatial and temporal variation in recruitment
Late post-settlement:
- growth - movement
competition predation
- survival
adult and juvenile interactions
e.g., Cowen 1983, Oecologia
(1) Keystone predator -- trophic cascades
- manipulated local presence of sheephead and observed red sea urchin behavior
- urchins more exposed and mobile in absence of sheephead
- sheephead (Semicossyphus pulcher) in So. Calif.
Role of fishes in kelp forest communities
Cascading Effects of Predator Removal
sea otters sheephead
sea urchins
barrens kelp forest
rockfishes
Southern California Central California
lobster
New Zealand snapper
Sea urchin
Ecklonia
banded wrasse
barrens
Another example from down under:
e.g., Bray et al. 1981, Science (2) Enhanced nutrient availability and productivity
- monitored nutrient availability and macroalgal production in crevices with and without blacksmith
Role of fishes in kelp forest communities
- planktivorous blacksmith (Chromis punctipinnis) hole up in crevices at night
- greater nutrient availability and macroalgal production in crevices with blacksmith
- example of planktivorous fishes directing planktonic production to benthos
e.g., Gaines and Roughgarden 1987, Science (3) Planktivorous fishes reducing larval supply
- could be hydrodynamic influence of kelp or predation by planktivorous juvenile rockfishes
Role of fishes in kelp forest communities
- reduced recruitment of intertidal barnacles in years with thick Macrocystis forest at Hopkins
- used barnacle molts to decouple potential causes
- barnacle molts not reduced as they passed through forest, concluded reduction due to planktivory
- high recruitment of planktivorous juvenile rockfishes in years with thick Macrocystis forest
Midterm Results Percentages • Average = ~ 76 • High Score = 94 • Low Score = 53 Points • Total possible points 83
• 35 pts for scantron + 48 points for written