coral reef conservation in a changing climate: risk ... 1 pdf...conference on coral reefs, climate,...

Conference on Coral Reefs, Climate, & Coral BleachingJune 18 – 20, 2003, Turtle Bay Resort Hotel, Oahu, Hawaii

Coral reef conservation in a changing climate:Risk minimization and MPAs

Terry Done

Reef Futures [email protected]

a. Land-based Sources of Pollution

b. Overfishing

c. Lack of Public Awareness

d. Recreational Overuse and Misusee-1. Climate Change and Coral Bleaching

e-2. Disease

Climate Change and Coral Bleaching

A Focus Areas for US CRTF

The changing climate of coral reefs

temperatures (2 – 4oC hotter)

sea level(0.1 – 0.4 m higher)

atmospheric carbon dioxide(3 x more)

cyclone regimes(more extreme)

IPCC Predictions for this Century

US Coral Reef Task Force:

The National Action Plan

calls to strengthen the effectiveness of existing MPAs, and establish new MPAs where appropriate

•Do MPAs have a role in mitigating the effects of climate change?

•Where are the most appropriate places in a warming world?

ICRI believes MPAs do have a vital role as a measure to mitigate regional impacts of

climate changeRecommendations from ITMEMS 2 March 2003

Factor risk of bleaching impacts into management...

Support resilience of coral reefs through:good MPA design,

MPA networks and,reducing threats within management control.

Try to pick winners or simply spread the risk?

Design for a purpose….resilience

Impacts of hotter seasDecades

Weeks

Years

Mediumimpact

Catastrophicimpact

‘Collapsed’ (well grazed)

Very lowimpact

Weeks

RecoveryPoor Recovery

‘Bleached’ (alive)Dead

Mediumimpact

Very lowimpact


Catastrophicimpact

‘Collapsed’

Decades

Months

Resilience – physiological and ecological

‘Collapsed’ reef (under-grazed)

Poor Recovery Recovery

Physiolog-ically

Resilient


Ecologically Resilient

Settlement and growth of reef-

buildersWEAK STRONG

Not Resilient

GoodSettlement and growth of reef-

builders

Good MPA design and management

Ecological Resilience

An MPA network

Source of reef building larvae

‘Collapsed’ reef

Settlement

Good MPA design means collapsed reefs can rely on

neighbors for reef-building larvae

Growth

Good management provides good

environment for settlement and growth of reef

builders

may require local threat reduction

Try to pick winners or simply spread the risk?

Pattern of risk well known Pattern of risk poorly known

Risk of majorBleaching

High

Medium

LowAn MPA network

2000 2200 2240 2260 2280 2100

Tem

pera

ture

Cha

nge

o C

6

5

4

3

2

1

0

Year

High tech, high emissions

A1FI

High tech, low emissions

A1T2050

2100

2100

2050

IPCC projections for average global air temperatures

‘Buying time’ for our reefs Average global air temperature

Implications for coral reefs – depend on where

2070

24-29

29-3030–31>31

1990

2070

Joanie Kleypas John Guinotte

24-29

18–24 O C

29-3030–31

Sea Surface Temperature

… at a global scale…

The heat hazard –

summer of 2001-2 on the Great Barrier

Reef

~100 km

… and a regional scale…

Coastal

Offshore

The heat hazard –

summer of 2001-2

… and a local scale…

Different places have different level of future hazard

A1FI

A1T

Coastal reefMid-shelf and offshore reefs

Coastal reefs

Mid-shelf and offshore reefs

1

R. Jones, CSIRO

Depth (m)

0

100

200Coastal Outer shelf .

150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

That was the hazard – what about the impacts?

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

Depth (m)

0

100


150 kmMid-shelf.

Depth (m)

0

100

200Coastal Offshore

150 kmMid -shelf

0

80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)

28 29 30 31 32 Temperature o C


Offshore reef

Mid-shelf reefCoastal reef

Offshore reef

-shelf reefCoastal reef

0

80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



Offshore reef


Offshore reef


Offshore reef


Offshore reef


R. Berkelmans

5

4

3

2

1

Catastrophic

Medium

Very low‘Setback’

20 y

5 y

0 y

Catastrophic

Medium

Very low

……depends on the reef’s location, type and experience

Risk = hazard x negative consequences

Therefore there are two risk minimizing strategies

1. Minimize the hazard 2. Minimize the negative consequences

Risks to coral reefs – depends on where they are

(both hazard and vulnerability vary in space)

Risk – is changing as climate changes

Risk = probability of an unmanageable impact that negates management objectives

Flood - every 5 y COTS* - ‘never’Cyclone –every 15 y Bleaching – every 5 y

Flood - every 30 y COTS - every 15 y Cyclone – every 15 y Bleaching every 10 y

Flood ‘never’ COTS - ‘never’ Cyclone – every 15 y Bleaching – ‘never’

1990s

COTS*Crown of

Thorns Starfish

Risk – depends on where you are

1990s (2040s) Risk – changing with climate

Flood - every 5 y (?)COTS - ‘never’ (?)Cyclone –every 15 y (10 y)Bleaching – every 5 y (1 y)

Flood - every 30 y (15 y)COTS - every 15 y (?)Cyclone – every 15 y (10y)Bleaching every 10 y (3y)

Simulating probable future risks

010

10

20

30

40

30 50 70 90 110 130Exceedance of reef bleaching threshold (days)

Like

lihoo

d (%

)

2050

2010

2030

1990

Very Low Medium Catastrophic

CSIRO ReefClim

0

10

20

30

40

10 30 50 70 90 110 130

Exceedance of threshold (days)

Like

lihoo

d (%

)

1990

20102030

2050

Very Low Low Medium High Catastrophic

0

10

20

30

40

10 30 50 70 90 110 130


Like

lihoo

d (%

)

1990

20102030

2050


1990

20102030

2050

Very Low Low Medium High CatastrophicConsequences of a high tech future

… fossil fuel intensive

0

10

20

30

40

10 30 50 70 90 110 130


Like

lihoo

d (%

)


0

10

20

30

40

10 30 50 70 90 110 130


Like

lihoo

d (%

)

Very Low Low Medium High CatastrophicVery Low Low Medium High Catastrophic … transition to low emissions

Coastal reef

… low emissions future

Different places – same emissions

0

10

20

30

40

10 30 50 70 90 110 130


Like

lihoo

d (%

)


0

10

20

30

40

10 30 50 70 90 110 130


Like

lihoo

d (%

)

Very Low Low Medium High CatastrophicVery Low Low Medium High Catastrophic

Coastal reef 1990 2050

0

10

20

30

40

10 30 50 70 90 110 130Exceedance of threshold (days)

Like

lihoo

d (%

)


0

10

20

30

40

10 30 50 70 90 110 130Exceedance of threshold (days)

Like

lihoo

d (%

)

Very Low Low Medium High CatastrophicVery Low Low Medium High Catastrophic

1990 2050

Offshore reef

C.Very Low Low Medium High Catastrophic

0

10

20

30

40

10 30 50 70 90 110 130


Like

lihoo

d (%

)

Are some global regions and/or local reefs at lower risk?

Global climate change would be less of an issue at this place – do they exist?

Tools and data requirements:

•CSIRO ReefClim model•Daily(?) sea temperature (~ 10y)•local bleaching thresholds

Your reef?

What do increasing bleaching days per summer mean for coral communities? Appearance? Ecology?

Decades

Months

‘Collapsed’ reef (under-grazed)

WeeksYears

0

80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



Offshore reef


Offshore reef


0

80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



Offshore reef


Offshore reef


Offshore reef


Offshore reef


R. Berkelmans

0

80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



Offshore reef


Offshore reef


0

80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



80

60

40

20

Cum

ulat

ive

expo

sure

tim

e (d

ays)



Offshore reef


Offshore reef


Offshore reef


Offshore reef


R. Berkelmans

20 y

10 y

5 y

3 y

0 y

20 y

10 y

5 y

3 y

0 y

10 y

5 y

1 y

.5 y

0 y

10 y

5 y

1 y

.5 y

0 y

Ecology Appearance‘Setback’

‘Setbacks’

‘Appearance’ (~coral cover)

-100

-50

0

50

1990 2000 2010 2020 2030 2040 2050

Prog

ress

Inde

x (y

ears

)

Higher emission scenarioLower emission scenario

1990 baseline

This global greenhouse gas emissions policy buys some time for this reef

Inde

x of

Ree

f Sta

te (Y

ears

)

ReefState 1.0

Median state(10,000 runs)

-100

-50

0

50

1990 2000 2010 2020 2030 2040 2050

Prog

ress

Inde

x (y

ears

)‘Ecology’ (coral cover + composition and size structure)

Same place, same scenarios

Higher emission scenarioLower emission scenarioIn

dex

of R

eef S

tate

(Yea

rs)

ReefState 1.0

More adaptive capacity

Local management that works

Needed: local management that works to foster resilience(I.e. effective MPAs and threat reduction)

The models match observations so far… reefs have tracked the 1990s’ baseline

19 01119 011

AIMS Long Term Monitoring Project

Seaweeds

Staghorn and table corals

Porites heads and thickets

Softs

Faviids

Pocilloporids

ReefState 2.0

Seaweeds



Softs

Faviids

Pocilloporids

Seaweeds



Softs

Faviids

Pocilloporids

driftSeaweeds



Softs

Faviids

Pocilloporids

Seaweeds



Softs

Faviids

Pocilloporids

ReefState 2.0

Seaweeds



Softs

Faviids

Pocilloporids

Seaweeds



Softs

Faviids

Pocilloporids

drift

SeaweedsSofts

Pocilloporids

Faviids

Staghorn thickets and plates


dynamic equilibrium

SeaweedsSofts

Pocilloporids

Faviids



dynamic equilibrium

1990 2020 2050

Hard coral cover

Management that has worked

(Benefit of hindsight!)

1990 2020 2050

100%

Seaweeds


Softs FaviidsPocilloporids

Poritesheads and thickets

phase shift

ReefState 2.0

Seaweeds




phase shift

Seaweeds




phase shift

ReefState 2.0

Seaweeds




phase shift

Management that has

not workedHard coral

cover

Collapsed – ungrazed

SeaweedsSoft corals

Hard corals

Collapsed – heavily grazed

SeaweedsSoft corals

Hard corals

Avoid these

The challenge: without the benefit of hindsight..

Picking winners (lower cost, higherrisk strategy)

Most resilient

Not resilient

Monitoring

alone will not

give you the

answer!

Pick these

Needed to pick places that will be winners:

1. Identifying places with low hazard.

2. A realistic basis for using local ecological knowledge to rate individual reefs according to their likelihood of desirable versus undesirable future reef trajectories

• dynamic equilibrium•change in coral composition only (drift)•phase shift•collapse

…..using local ecological knowledgeHow post-bleaching impact surveys can help us pick winners

AIMS and CRC ReefJanice Lough

Craig Steinberg

Mike Mahoney

Mary Wakeford

Emre Turak

Ray Berkelmans

Stuart Kininmonth

Mary Wakeford

Madeliene Van OppenGlenn De’ath

Scott Wooldridge

Al Strong (NOAA)

William Skirving (NOAA)

John Guinotte (KU/JCU)

Rod Salm (TNC)

Paul Marshall (GBRMPA)

Roger Jones (CSIRO)

Peter Whetton (CSIRO)

Thanks to…

GREAT BARRIER REEFMARINE PARK AUTHORITY

The Nature Conservancy

~ 500 km Field access to GIS with high resolution SST maps and 10 year

satellite archive were invaluable to post-bleaching impact assessment

Cumulative heat stress summer 2001-2

Maximum heat stress summer 2001-2

Acclimatization regime1990s

1 km pixels

Index of summer heat

GIS was created for selection of assessment

sites

Normal Bleached Dead

Field assessments of sitesOne bar per site

Did the 2002 index of hazard (heat anomaly) explain the bleaching impact?

y = 9.3933Ln(x) + 29.4R2 = 0.4253

0102030405060708090

0 20 40 60 80Days >2SD above climatology

Ble

achi

ng im

pact

(%)

Summer 2002 heat anomaly index

Ble

achi

ng im

pact

inde

x

y = 9.3933Ln(x) + 29.4R2 = 0.4253

0102030405060708090

0 20 40 60 80Days >2SD above climatology

Ble

achi

ng im

pact

(%)

Summer 2002 heat anomaly index

Ble

achi

ng im

pact

inde

x • Interactions and conditional dependencies with other causative factors

• Inaccuracies in SST• Not the best index of

SST• Not the best index of

bleaching impact • Differences in

vulnerability of coral species and communities

Acclimatization regime?

No: there were…

Which locations passed the test of summer 2001-2?

15 1712 173 610

30

50

Low Med - High Low Med - High

No.

Site

s

Low Med - High

94 94

Low Med - High

Coral bleaching Coral mortality

Medium -High

Medium – Highimpact

Low impact


Low impact

Low Medium -High


Low impact


Low impact

LowLow Medium-High

resistant to climate-related coral bleaching?

What made those reefs resistant?Were they exposed to an anomaly?

A. May be overheated next time

B. Unlikelyto be

overheated

D. PoorlyAdapted

C. WellAdapted

LowHigh

Coral survival

GoodOceanography

Good Luck

Reason

YesNo

Places with reliable mixing with cool watersPlaces where strong flows resuspend sediments and increase shadingDeep reefs

‘Right’ history of acclimatization‘Tough’ coral communities presentPrevalence of heat resistantzooxanthellae genotypesSynergistic effects – location, type, history

Turbid water reefs Clear water reefs

Physical models of heat hazardW.Skirving and C.Steinberg

Acclimatization:Normal summertime averages from satellite SSTsM. Mahoney


‘Right’ history of acclimatization‘Tough’ coral communities presentPrevalence of heat resistantzooxanthellae genotypes

Better explanatory power used in combination than when tested singly

Promising insights using a Bayesian approach

GIS proxies for mixing, cooling and acclimatization

Categories of coral community types and habitats


‘Right’ history of acclimatization‘Tough’ coral communities presentPrevalence of heat resistantzooxanthellae genotypes

2. Remote sensing and GIS

mixinglowmediumhigh

31.334.034.7

sst1kmlowmediumhigh

34.133.932.0

communityKM1KM2KM3KM4

31.423.328.816.4

bleachHIGHLOWMEDIUM

25.935.238.8

deadHIGHLOWMEDIUM

30.531.038.5

sst50kmlowmediumhighextreme

22.624.227.925.3

cost100lowmediumhigh

36.935.727.3

habitatBACK RFCHANNELFRINGELAGOONOUT SLP

35.99.6221.816.716.0

What combination of

information best explained places where mortality was

low

Bayesian Belief Network combines:•Expert opinion•Learnt dependencies

A Mixing index using

current vectors depth

model

NOAA 50 km products hotspots, Degree

heating weeks

An Index for ease of mixing

with cool water from

100 m

AIMS 1 km SST products

Index for Acclimatization

regime

Index of bleaching for

‘sites’

Categories of reef habitat

and community type

Index of mortality for ‘sites’

1. Ecology and post-bleaching impact surveys

‘…reefs are deteriorating from coral bleaching and mortality due to warming

seas….’

‘…counteract these trends by adopting a number of risk minimising strategies.’

Statement from Second International Marine Ecosystem Management Symposium,

Manila, Philippines, March 24-27 2003

Thank you

Internal bioeroders

Fish, coral and coralline algae dominance

Turf algal dominance

Bleaching, coral predators, diseases

Sea urchin reduction with reduced fishing

Fleshy algae reduction with reduced fishing

Nutrients/organic matter and fishing

Sediments and fishing

Turf algal dominance

Various algae, heterotrophs and bioeroders

Pollution and fishing

Urchin diseases

Urchin recruitment

Large-scale sea urchin reduction with continued fishing

Small-scale sea urchin reduction with continued fishing

Fleshy algal reduction with continued fishing

Reduce fishing

Reduce fishing

Local conservation actions

(McClanahan,Polunin and Done)

Sea urchin and turf dominance

Fleshy brown algal dominance

Fishing

coral reef conservation in a changing climate: risk ... 1 pdf...conference on coral reefs, climate,...

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