13 - marine ecology · 10’s to 100’s of km = 30 days “ ... 70 (1998) (1999) (2000) el niño...

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