Santa Barbara Coastal LTER &

California’s Marine Protected Areas

Dave Siegel

University of California, Santa Barbara

Santa Barbara Coastal LTER

Santa Barbara Coastal

Long Term Ecological Research

• ~ 10,000 km2

• Steep coastal mountains• Small estuaries• Shallow rocky reefs• Deep ocean basin• Offshore islands

• Mediterranean climate• Strong ENSO signal• Major biogeographic boundary

Giant Kelp Forests

• Worldwide distribution on shallow temperate reefs

• High productivity

• High species diversity

• Complex trophic interactions

• Biological habitat formation

• High economic importance

U.S. West Coast Rockfish

Source: Pacific Fisheries Management Council, 2001

0%

20%

40%

60%

80%

100%

120%

140%

1960 1965 1970 1975 1980 1985 1990 1995 2000

Year

widow

darkblotched

canary

bocaccio

cowcod

POP

unfished

overfishedthreshold

rebuildingtarget

How a MPA might work

• MPA’s allow adults grow to full maturity

• Elimination of harvest enables more “natural” communities & food webs to exist

• Obvious tool for near-sedentary adults

• Fishery benefits if progeny disperse broadly or adults “spill out” of the MPA

Fished Organism Life Cycle is Important

How a MPA might work

Key: Spatial Management of a Fishery

Fish(x)MPA

Distance ->

Spillover

MPA’s Work WithinTheir

Borders

From Halpern [2002]

A Benefit of Getting Old & Fat

MPA’s in Channel Islands

• State-federal process to implement

Marine Protected Areas around the

Channel Island National Marine Sanctuary

• Stakeholder driven goals:

– protect biodiversity

– maintain fishery yields & incomes

Conservation vs. Fisheries

Valu

e

Fractional Set Aside

Conservation Goal

Fishery Goal

We were victims of public service...

• Six SBC-LTER PI’s served on the Science Panel for the Channel Islands Marine Reserve process

• Helped the stakeholder panel arrive on a “preferred alternative” MPA plan

• This plan has been implemented by the State

Approved Oct. 24, 2002 forstate waters

Federal approval in the works

What did/can SBC-LTER contribute??

• Local data & expertise

– SBC-LTER & partner program data

• Theoretical & synthetic analyses

– How big, how many, how connected?

– How hard will it be to assess MPA efficiency??

• Next steps

– Flow, Fish & Fishing (F3) Biocomplexity Project

– MLPA, California-wide MPA designation legislation

Kinlan & Gaines [2003; Ecology 84: 2007-2020].

Dispersal Scales for Marine Organisms

Larval Transport Modeling

• Provide a metric for source-to-destination exchanges among nearshore populations

• Incorporate important oceanographic & organism life history characteristics

• Constrain using easily obtained observations

• Useful for modeling spatial population dynamics

Siegel et al. [2003; Marine Ecology Progress Series 260: 83-96]

Larval Transport Modeling

Planktonic larval duration: 6 to 8 weeks

Flow Statistics: U = 5 cm/s, u = 15 cm/s

-600 -400 -200 0 200 400 600 800 10000

10

20

30

40

50

60

70

80

90

100

U = 5 ustd = 15 To = 42 T

f = 56

tota

l set

tlers

= 1

024

tot

al p

art

= 5

000

alongcoast (km) (a,b,c = 84.815 200.39 216.62)

N = 5000

Regional Scale Self Seeding

What fraction of larvae settle within a region of size L?

Will a MPA seed itself or its surroundings?

Scales as Dd/LDd

smallL large

Dd large

L small

A MPA will retain or export progeny based on the organism’s dispersion scale & the size of the MPA

Will a MPA Retain or Export??D

esig

n fo

rExport

Desi

gn

for

Con

serv

ati

on 50%

retention

Dd/L~0.5

Is a MPA a Source or Sink?

• A single MPA will be both a larval source &

sink

• Points to networks of reserves for

conservation

If MPA has L= 10 km, exports if Dd 5 km

Retains Exports

Reserve Networks

• Enable conservation & fisheries goals to be achieved simultaneously

• Reserves must not be spaced too far apart

Size --> adult movementSpacing --> larval

dispersal

Approved Oct. 24, 2002State waters implemented

Federal in the works

Larval Transport, Time & Fish Stock Uncertainty

• Larval dispersal calculated represents

ensemble mean conditions

• The implied time to construct this

mean estimate is ~20 years!!

– Assumes larval releases are daily & a

decorrelation time scale of 3 days

• Annual recruitment may be a small sampling of the kernel (N = 10?, or less!!)

– (300 releases / year) * (10% survival) / (3 day L)

• Example - intermediate disperser (N = 100)

Time, continued...

-100 -50 0 50 100 150 200 250 300 3500

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

U = 5 Ustd = 15 To = 14 Tf = 21

tota

l set

tlers

= 1

3 t

otal

par

t =

100

alongcoast (km)

• Implies that connections among sites are stochastic & intermittent

• Critical for assessing “MPA success” as a fishery tool

N=5000

160 180 200 220 240 260 280 300 3200

10

20

30

40

50

60

70

JD 2001

# se

ttle

rs/d

eplo

ymen

t

Ellwood Invert Setttlment Time Series

Mytilus Clams (excl razor & HIAARC) any marine snail (excl. veligers, limp)Limpet species Snail veliger any seastar Hiatella arctica

Time series sampling – t = 2 d

Invertebrate Settlement – SBC-LTER/PISCO

Interpreting Settlement Time Series

• Stochastic, quasi-random time series

• No correlation of settling among species

• Few settlement events for each species

• Events are short

(2 days)

160 180 200 220 240 260 280 300 3200

10

20

30

40

50

60

70

JD 2001

# s

ett

lers

/deplo

ym

ent

Ellwood Invert Setttlment Time Series

Mytilus Clams (excl razor & HIAARC) any marine snail (excl. veligers, limp)Limpet species Snail veliger any seastar Hiatella arctica

Implications for MPA Assessment

• MPA increases in fishery yields will be difficult to discern from inherent system variability

• A variable fishery response is expected

• Proper MPA assessment needs to be done over some long time (not really known yet)

• Need real predictive tools (including fishing

dynamics)

Flow, Fish & Fishing - www.icess.ucsb.edu/~davey/F_cubed

MPA’s in California

• Marine Life Protection Act (AB993)

– Implement a MPA network for California

– Take a regional approach to siting marine reserves

– SBC-LTER participants are part of this process

– On hold due to state budget … but it is the law!!

SBC-LTER & the MPA Process

• Theoretical & synthetic analyses for MPA

– How big, how many, how connected?

– Assessment of MPA efficiency??

• Other relevant SBC results for MLPA process

– Long-term observations of the kelp ecosystem

– Terrestrial inputs of nutrients, sediments, etc.

• Our forays into the world of “broader impacts” will continue throughout SBC’s lifespan

Thank You!!