Quantitative observations of a major coral bleachingevent in Barbados, Southeastern Caribbean

Hazel A. Oxenford & Ramon Roach &

Angelique Brathwaite & Leonard Nurse &

Renata Goodridge & Fabian Hinds & Kim Baldwin &

Christine Finney

Received: 17 January 2006 /Accepted: 10 May 2007 / Published online: 6 September 2007# Springer Science + Business Media B.V. 2007

Abstract In late summer 2005 a mass coral bleaching event occurred in the Caribbean.Here we quantify coral bleaching in Barbados at six sites on the island’s sheltered west andexposed southwest coasts, including nearshore fringing and patch reefs and offshore bankreef habitats. Onset of coral bleaching occurred in late August 2005 and persisted for manymonths after temperatures cooled. All reef habitats and virtually all coral taxa were affected,with an average of 70.6% of all colonies bleaching. Nearshore reefs (<10 m depth) wereaffected more severely than offshore deeper reefs (>15 m) with an average of 80.6% of allcoral colonies bleaching compared with 60.5% on the latter. Inter-species variation insusceptibility to bleaching was marked with >90% of colonies bleaching in some specieswhilst <10% bleached in others. Follow-up surveys revealed low coral mortality, with anoverall mean of 3.8% partial colony death across all species and reefs by February 2006.However, bleached condition has persisted with a mean of 37.7% of all coral colonies stillbleached after 5 1/2 months, indicating that loss of live coral is likely to continue for sometime. This event represents the most severe bleaching episode ever witnessed on Barbados’reefs and emphasises the vulnerability of small island states, with a high reliance on healthycoral reef ecosystem services, to elevated sea water temperatures associated with climatevariability and global climate change.

1 Introduction

Coral reefs are important natural assets, providing vital goods and services to many coastalcommunities in the tropics, especially small island states. Barbados is no exception andrelies heavily on healthy coral reef ecosystems to maintain beaches and support nearshore

Climatic Change (2008) 87:435–449DOI 10.1007/s10584-007-9311-y

H. A. Oxenford (*) : L. Nurse : R. Goodridge : K. Baldwin : C. FinneyCentre for Resource Management and Environmental Studies (CERMES), University of the West Indies,Cave Hill, Barbadose-mail: hoxenford@uwichill.edu.bb

R. Roach : A. Brathwaite : F. HindsCoastal Zone Management Unit (CZMU), Ministry of Housing, Lands and the EnvironmentGovernment of Barbados, Bridgetown, Barbados

fisheries and tourism (National Commission on Sustainable Development 2004). Howeverthere is serious concern about the threat that global warming poses to the long-term survivalof coral reefs (Brown 1997; Hoegh-Guldberg 1999; Hughes et al. 2003; Berkelmans et al.2004). Regional-scale mass coral bleaching episodes and subsequent high coral mortalityare irrefutably linked to ocean warming, occurring when sea-surface temperatures reach ≥1°Cabove regional climatological maximum monthly means (Glynn 1993; Wilkinson 1996;Brown 1997; Hoegh-Guldberg 1999; Reaser et al. 2000; IPCC 2001; Bruno et al. 2001;Wellington et al. 2001; Hughes et al. 2003). Furthermore, there is strong evidence that thefrequency and intensity of bleaching has increased over the last two decades (Winter et al.1998; Hoegh-Guldberg 1999; McWilliams et al. 2005). These observations have significantecological and socio-economic implications in the face of predictions that sea surfacetemperatures will continue to rise sharply above the 1990 baseline (by as much as 1–3°C)over the current century (Hoegh-Guldberg 1999; IPCC 2001; Lal et al. 2002). Projectionssuggest that bleaching could become an annual event within the next 30–50 years(Intergovernmental Panel on Climate Change 1996; Pockley 1999), with the highestincidence in the Caribbean (Hoegh-Guldberg 1999).

There are a few references to bleaching in Barbados (see CARICOMP 1997; Williamsand Bunkley-Williams 1988; Smith et al. 2000; Hoetjes et al. 2002; Goldberg andWilkinson 2004) and two ad hoc reports submitted to ReefBase in 1986 and 1998. Thesereports, although largely anecdotal, are consistent with other southeastern Caribbean islandsin suggesting that bleaching events in this region of the Caribbean basin have beeninfrequent, of low to moderate intensity and have occurred within the last decade (seeMcWilliams et al. 2005 for review). Here we report for the first time on a major bleachingevent in Barbados during the summer of 2005.

2 Materials and methods

Quantitative coral bleaching surveys were conducted at six representative coral reef habitatson the sheltered west and exposed southwest coasts of the island from September15–October 6, 2005 (Fig. 1, Table 1). These were repeated from February 6–10, 2006 to assesspersistence of bleaching and extent of mortality. Five haphazardly placed 20×1 m belttransects (CARICOMP 2001; Oliver et al. 2004) were surveyed at each reef site in thevicinity of permanent reef monitoring plots wherever possible. All coral colonies withinbelt transects were identified to species, counted, and their condition (bleached or non-bleached, and percent of colony recently dead) recorded. Species complexes whichpresented difficulty among observers in reliable identification at some sites (i.e. Montastreacomplex: Montastrea annularis, M. faveolata and M. franksi; and Agaricia species:Agaricia agaricites, A. humilis, A. lamarcki and A. grahamae) were recorded at the genuslevel and treated in the analyses thereafter as single species.

Benthic water temperature data were collected in each of the major reef habitat typesusing HOBO StowAway® XTI temperature loggers in underwater housings, set to recordthe temperature at 4 h intervals. Temperature loggers were calibrated together against aregular laboratory grade thermometer and were attached to the reef substrate. Mesoscale(50 km grid) night-time sea surface temperature (SST) data for Barbados and computeddegree heating weeks (DHWs) were obtained directly through the NOAA/NESDIS CoralReef Watch website (http://coralreefwatch.noaa.gov/index.html).

436 Climatic Change (2008) 87:435–449

Numbers of bleached and non-bleached colonies were used to determine the percentbleaching for each transect. Partial colony mortality (as percent of colony recently dead)was averaged over all colonies within a transect. Data were tested for normality andhomogeneity of variance before parametric statistical analysis. Reefs were grouped by coast(west or southwest) and by water depth (shallow <10 m or deep >15 m). Nearshore fringingand patch reefs were considered shallow and offshore bank reefs were considered deep.

Fig. 1 Map of Barbados showing extent of coral reefs and location of survey sites. Insert map showslocation of Barbados in the southeastern Caribbean

Climatic Change (2008) 87:435–449 437

Tab

le1

Sum

maryof

surveyed

reef

characteristics

Reef

type

Location

bycoast

Site

name

GPS

coordinates

Depth

(m)

2005

2006

Survey

date

Total

no.

hard

coral

species

(100

m2)

Totalno.

colonies

(100

m2)

No.

species

bleached

Mean%

colonies

bleached

(SE)

Survey

date

Mean%

colonies

bleached

(SE)

Mean%

colony

dead

(SE)

Percent

live

coral

cover

Datasource

for

livecoralcover

Patch

West

Batts

N13°08′08.6″

815-Sep

20791

1573.8

(6.8)

7-Feb

46.0

(1.7)

1.6(1.2)

29.9

Current

study

Rock

W59°38′18.3″

Bank

West

Maycocks

N13°17′32.85″

2223-Sep

16409

1459.1

(2.1)

9-Feb

32.6

(2.7)

4.2(1.7)

37.8

Hunte

2001

W59°39′47.53″

Bank

West

Atlantis

N13°07′18.9″

16–2

030-Sep

17445

1563.0

(3.8)

7-Feb

43.7

(6.7)

4.4(1.2)

34.0

Hunte

etal.,

unpublisheddata

June

2005

W59°38′55.2″

Fringing

West

North

Bellairs

N13°11′18.0″

3–5

4-Oct

171629

1482.0

(3.1)

9-Feb

39.7

(8.7)

8.3(3.6)

23.3

Oxenfordand

Goodridge,

unpublished

data,March

2005

W59°38′31.0″

Bank

Southwest

WelcomeInn

N13°03′35.0″

155-Oct

21621

2059.4

(6.9)

6-Feb

43.1

(3.0)

3.1(0.7)

22.9

Hunte

etal.2005

W59°33′25.0″

Patch

Southwest

Coconut

Court

N13°04′24.4″

5–6

6-Oct

16713

1586.0

(1.3)

6-Feb

19.9

(1.5)

1.2(0.8)

25.8

Hunte

etal.2005

W59°36′11.3″

Overall

3–22

294608

2670.6

(4.8)

37.5

(2.5)

3.8(0.8)

28.9

Percent

livehard

coralcoverdata

weresourcedfrom

ongoingmonito

ring

atadjacent

sites.Allotherdata

werecollected

during

thecurrentbleachingsurveys.

438 Climatic Change (2008) 87:435–449

3 Results

3.1 Water temperatures

The benthic water temperature time-series for a selection of the surveyed reefs showsconsistency among all reef habitats in the temperatures experienced through the June 2005to February 2006 time-series (Fig. 2). Daily mean benthic temperatures climbed steadilyfrom around 28.7°C in late June to over 30°C in late August and early September,representing an increase of at least one degree over previous summer records (Oxenford andGoodridge, unpublished data set; CARICOMP 1997). During the second and third weeks ofSeptember strong surface currents brought cooler water onto the reefs causing temperaturesto drop by almost 1.5°C, before rising steeply again to 30°C for the last week of September.Mean daily temperature then declined steadily to 26.7°C by February (Fig. 2). Extremelyhigh temperatures at depth (30–31°C on both shallow and deep reefs down to at least 30 m)were corroborated by numerous reports from research divers and dive operators from manydive sites on the west and southwest coasts during late August through September 2005.

NOAA satellite derived mesoscale sea surface temperature (SST) data for the easternCaribbean, including Barbados, indicated a coral bleaching hotspot (SSTs in excess of 1°Cabove the maximum expected temperatures) developing in the Atlantic to the east ofBarbados in early June, strengthening through June–July and covering Barbados and theLesser Antilles island chain by early August. The hotspot continued to develop throughoutthe summer covering much of the Caribbean basin by early October and finally diminishingand disappearing by late October (Fig. 3). Accumulated heat stress for the easternCaribbean including Barbados was severe, being in excess of five Degree Heating Weeks(DHWs) for much of the summer and reaching a maximum of 13–14 weeks by the end ofOctober and beginning of November (Fig. 4).

3.2 Bleaching response

Bleached corals were first observed on August 24 after one week of exposure to watertemperatures in excess of 30°C. Thereafter, whole colony bleaching spread rapidly andsimultaneously on deep and shallow reefs, and by mid-September there was widespreadbleaching of hard corals at all reef habitats on both the sheltered west and exposedsouthwest coasts of the island (Fig. 5).

Between mid-September and early October 2005 some 4,608 colonies from 29 hardcoral species (or species complexes) were surveyed at the six reef sites (Table 1). State of

26.5

27.5

28.5

29.5

30.5

30-J

un

7-Ju

l

14-J

ul

21-J

ul

28-J

ul

4-A

ug

11-A

ug

18-A

ug

25-A

ug

1-S

ep

8-S

ep

15-S

ep

22-S

ep

29-S

ep

6-O

ct

13-O

ct

20-O

ct

27-O

ct

3-N

ov

10-N

ov

17-N

ov

24-N

ov

1-D

ec

8-D

ec

15-D

ec

22-D

ec

29-D

ec

5-Ja

n

12-J

an

19-J

an

26-J

an

2-F

eb

9-F

eb

16-F

eb

Mea

n da

ily te

mpe

ratu

re (

o C )

Coconut Court

Batts Rock

Atlantis

North Bellairs

2005 - 2006

Fig. 2 Benthic water temperature time-series for surveyed reefs

Climatic Change (2008) 87:435–449 439

bleaching was severe across all reefs ranging from reef mean values of 59–86% of all hardcoral colonies (Table 1), and affected 90% (26 species) of all hard coral species surveyed(Table 2).

Extent of bleaching was affected by reef type (nearshore shallow vs offshore deep) butwas not influenced by coast orientation (west vs southwest) (two-Factor ANOVA: for reef

Fig. 4 Accumulated thermalstress over 12 weeks shown inDegree Heating Weeks (DHW)for the Caribbean on November1, 2005. Data image downloadedand adapted from NOAA/NES-DIS (http://www.osdpd.noaa.gov/PSB/EPS/SST/data2/dhwa.11.1.2005.gif)

Fig. 3 Development of the coral bleaching hotspots (shown in yellow to orange) for the Caribbean duringthe summer of 2005. Sea surface temperature anomaly scale in °C above SST maximum monthlyclimatology. Data images downloaded from NOAA/NESDIS (http://www.osdpd.noaa.gov/PSB/EPS/SST/climohot.html)

440 Climatic Change (2008) 87:435–449

type F=30.82, df=1, p<0.001; for coast F=0.696, df=1, p=0.412). Furthermore, theinteraction term was not significant (F=1.572, df=1, p=0.221) such that coast was notconsidered further in the analyses. The shallow nearshore fringing and patch reefsexperienced more severe levels of bleaching than the deeper offshore reefs, with an overallmean value of 80.6% of all colonies bleached (range=73.8–86.0%) for shallow reefscompared with 60.5% (range=59.1–63.0%) for the deeper offshore reefs (Table 1).

Fig. 5 Severe coral bleaching at survey sites. Top row: North Bellairs fringing reef; second row: Batts Rockpatch reef; third row: Atlantis bank reef; bottom row: Coconut Court patch reef

Climatic Change (2008) 87:435–449 441

Tab

le2

Listof

coralspeciesobserved

over

allsurveyed

reefs,show

ingthenumberof

bleached

andnon-bleached

colonies

inSept-Oct

2005

Class

Fam

ilySpecies

No.

bleached

colonies

No.

non-bleached

colonies

Totalcolonies

Percent

bleached

byfamily

Anthozoa

Agariciidae

Agariciaspp.

1,277

451,322

Leptoseriscuculla

ta1

01

96.6

Astrocoeniid

aeStepha

nocoenia

intersepta

711

1838

.9Caryophylliidae

Eusmiliafastigiata

210

1216

.7Faviid

aeColpo

phyllia

amaranthus

10

1Colpo

phyllia

natans

558

63Diploriaclivosa

41

5Diplorialabyrinthiform

is38

3775

Diploriastrigosa

226

5127

7Favia

frag

um10

111

Montastreacavernosa

152

8623

8Montastreacomplex

355

134

489

68.2

Meandrinidae

Dendrogyracylin

dricus

150

15Dicocoeniastokesii

37

10Meand

rina

meandrites

3854

9247

.7Mussidae

Isophylla

strearigida

10

1Mussa

angu

losa

20

2Mycetop

hylliaferox

02

2Scolym

iasp.

01

150

.0Pocilloporidae

Madracisdecactis

554

59Madracismirabilis

1144

5514

.0Poritidae

Poritesastreoides

711

373

1,084

Poritespo

rites

182

6825

066

.9Siderastreidae

Siderastrearadians

146

20Siderastreasiderea

210

108

318

66.3

Hydrozoa

Milleporidae

Milleporaalcicornis

7310

83Milleporacomplan

ata

364

40Milleporasquarrosa

4414

5884

.5Stylasteridae

Stylasterroseus

03

30

Totals

3,423

1,182

4,605

74.3

442 Climatic Change (2008) 87:435–449

Hard coral species composition differed among reefs but showed similar features betweenreef types (Fig. 6). Shallow reefs are dominated by large numbers of small colonies of avery few species. These species are typically Type I (brooders with high recruitment ratesand high juvenile mortality rates) such as the Agaricia spp. and P. astreoides, or highlyfragmented colonies of Type II (broadcast spawners, low recruitment rates, low juvenilemortality) such as the M. annularis complex. By contrast, deep reefs have a much greaterdiversity, with fewer, but larger sized colonies and more species represented, including bothTypes.

Species showed marked variation in the degree to which they were affected by bleaching(Table 2). Part of this variation can be explained by small sample sizes, but, markeddifferences are still apparent when only the more abundant species (10 or more coloniesobserved) are compared (Pearson’s chi-square test for independence: χ2=924.9, df=20,p<0.001; Fig. 7). Of these, the most resistant species were Colpophyllia natans andMadracis decactis with less than 10% of colonies bleached, whilst the most severelybleached were Agaricia spp., Favia fragum, Dendrogyra cylindricus, and Milleporacomplanata with 90% or more of the colonies affected (Fig. 7). At the family level therewas marked variation among the most common (>100 colonies observed) families(Pearson’s chi-square test for independence: χ2=692.3, df=6, p<0.001), with highestlevels of bleaching in the Agariciidae and Milleporidae (>84% of all colonies), and arelatively low level in the Pocilloporidae (<15%; Table 2).

Differences in bleaching response among the more abundant (n>10 colonies) andubiquitous species (occurring on both shallow nearshore and deep offshore reefs) wereapparent between the two reef environments. Two species (Diploria strigosa and P.astreoides) showed significantly more bleaching on shallow nearshore reefs, whilst onespecies (S. siderea) showed significantly more bleaching on deep reefs (Mann Whitneytests: p<0.05 for all three species; Fig. 8).

3.3 Onset of mortality and persistence of bleaching

Qualitative observation indicated rapid onset of mortality in a few species, notablyMillepora spp. and Porites porites with many colonies dying within a few weeks ofbleaching. The majority of corals however remained bleached but alive over the ensuingmonths. Repeat quantitative surveys at the six reef sites in February 2006, 5 1/2 monthsafter the onset of bleaching, revealed persistent bleached condition at all reefs with anoverall mean of 37.5% of all colonies still fully or partially bleached (Table 1). Recent lossof live tissue, as evidenced by exposed skeleton and/or a new cover of turf algae, wasobserved on many bleached colonies at this time, giving an overall mean of 3.8% colonydeath across all reef sites (Table 1).

4 Discussion

This event represents the most severe bleaching ever witnessed on Barbados’ reefs andcoincides with the first record of a significant Caribbean-wide sea surface temperature(SST) coral bleaching hotspot initiating over the eastern Caribbean (NOAA/NESDISdatabase archive http://www.osdpd.noaa.gov/PSB/EPS/SST/climohot.html). Our observa-tions are comparable with numerous reports (mainly qualitative) of unprecedented coralbleaching from other southeastern and northeastern Caribbean islands (NOAA NewsOnline, Story 2526, October 25, 2005; NOAA CHAMP Coral Listserver, Sept–Oct 2005;

Climatic Change (2008) 87:435–449 443

0

10

20

30

40

50

60

1

0

150

300

450

600

750

900

1

0

50

100

150

200

250

300

350

1

0

10

20

30

40

50

60

70

1

0

20

40

60

80

100

120

Aga

ricia

spp

.

L. c

ucul

lata

S. i

nter

sept

a

E. f

astig

iata

C. a

mar

anth

us

C. n

atan

s

D. c

livos

aD

.la

byrin

thifo

rmis

D. s

trig

osa

F. f

ragu

m

M. c

aver

nosa

Mon

astr

eaco

mpl

ex

D. c

ylin

dric

us

D. s

toke

sii

M. m

eand

rites

I. rig

ida

M. a

ngul

osa

M. f

erox

Sco

lym

ia s

p.

M. d

ecac

tis

M. m

irabi

lis

P. a

stre

oide

s

P. p

orite

s

S. r

adia

ns

S. s

ider

ea

M. a

lcic

orni

s

M. c

ompl

anat

a

M. s

quar

rosa

S. r

oseu

s

0

50

100

150

200

250

300

1

North Bellairs

Batts Rock

Coconut Court

Atlantis

Maycocks

Welcome Inn

Num

ber

of c

olon

ies

Fig. 6 Hard coral species composition for surveyed reefs shown as number of colonies recorded in 100 m2

444 Climatic Change (2008) 87:435–449

Miller et al. 2006; numerous personal communications e.g. O. Day (Tobago), L. Robertson(Grenada), A. Smith (St. Lucia), E. Weil (Puerto Rico), S. Gore (British Virgin Islands); andbleaching reports to ReefBase).

In Barbados, as reported elsewhere in the eastern Caribbean, the high benthic watertemperature anomaly lasted for many weeks and all reef habitats were severely affected (>59%colonies bleached) despite variation in coral community composition, water depth, distancefrom shore, and known variation in water quality indicators (Hunte et al. 1998; Government ofBarbados 1999). This widespread (across all reefs and hard coral taxa) and severe level(>20% of colonies affected) of bleaching, in response to an extended high SST anomaly,appears typical of mass bleaching episodes reported over the last two decades for otherregions within and outside the Caribbean (e.g. McGrath and Smith 1998; Hoegh-Guldberg1999; Spencer et al. 2000; Bruno et al. 2001; Aronson et al. 2002; Berkelmans et al. 2004).

Also typical of other major bleaching events is variation among coral taxa insusceptibility to bleaching (Williams and Bunkley-Williams 1988; CARICOMP 1997;

0

20

40

60

80

100

Aga

ricia

spp

.

S. i

nter

sept

a

E. f

astig

iata

C. n

atan

sD

.la

byrin

thifo

rmis

D. s

trig

osa

F. f

ragu

m

M. c

aver

nosa

M. C

ompl

ex

D. c

ylin

dric

us

D. s

toke

sii

M. m

eand

rites

M. d

ecac

tis

M. m

irabi

lis

P. a

stre

oide

s

P. p

orite

s

S. r

adia

ns

S. s

ider

ea

M. a

lcic

orni

s

M. c

ompl

anat

a

M. s

quar

rosa

Ag As Ca Faviidae Mean Poc Por Sid Milleporidae

% b

leac

hing

Fig. 7 Comparison of bleaching effect on the more abundant (10 or more colonies observed) hard coralspecies, shown as percent of all colonies bleached. Abbreviated family names: Ag Agariciidae, AsAstrocoeniidae, Ca Caryophylliidae, Mean Meandrinidae, Poc Pocilloporidae, Por Poritidae, SidSiderastreidae

0

20

40

60

80

100

Agaricia

spp.

D.

labyrinth

iform

is

D.

str

igosa

M.

cavern

osa

Monastr

ea

com

ple

x

M.

meandrite

s

M.

mirabilis

P.

astr

eoid

es

P.

porite

s

S.

sid

ere

a

M.

alc

icorn

is

% b

leachin

g

Shallow

Deep

Fig. 8 Comparison of mean percent bleaching of hard coral species between shallow and deep reefs. Onlycorals considered abundant (n>10 colonies) and occurring in both reef types are shown. Bars show mean SE,asterisk indicates significant difference

Climatic Change (2008) 87:435–449 445

Winter et al. 1998; Marshall and Baird 2000; Hughes et al. 2003; McClanahan 2004). Ourdata generally corroborate with other reports from the Caribbean suggesting highsusceptibility to bleaching in Agaricia spp., M. annularis, Porites spp., Siderastrea sidereaand Millepora spp., and no, or very low levels of bleaching in Madracis spp. (Lang et al.1988; Williams and Bunkley-Williams 1988; Goreau 1990; CARICOMP 1997; McGrathand Smith 1998; Winter et al. 1998). Variation in bleaching response among reefs atdifferent depths is also commonly reported during mass bleaching episodes and againsimilar to our own observations, with shallow reefs generally bleaching more severely thandeeper reefs (Fisk and Done 1985; Williams and Bunkley-Williams 1988; Berkelmans et al.2004). However, this trend is not always observed and may be reversed (Lang et al. 1988;Marshall and Baird 2000, Bruno et al. 2001). Variation from these generalised patterns inbleaching response, both within and among species and reefs, results from the fact thatresistance to bleaching is influenced by both intrinsic physiological factors (e.g. colony orspecies-specific state of health, host and symbiont genotype) and extrinsic environmentalfactors (e.g. localised temperature regime, solar radiation, water flushing rates, shading)acting synergistically (Marshall and Baird 2000; West and Salm 2003 for review).

Mass bleaching events are usually associated with large-scale loss of live coral cover (Glynn1984 2000; Mumby et al. 2001, Aronson et al. 2002; McClanahan 2004) and even loss ofcoral taxa from entire reef areas (Glynn 1988; Glynn and Weerdt 1991; Goreau et al. 2000;McClanahan and Maina 2003). In this study, coral mortality over the first 5 1/2 months wasrelatively low. However, given the fact that more than one third of all colonies remainedbleached at this time, and the fact that there may be a significant time-lag between loss ofsymbionts and effects on coral health (Edmunds et al. 2003), the true mortality impact of thisevent is likely to be considerably higher than reported so far. High levels of mortality havealready been reported within 6 months of the onset of the 2005 bleaching event in the USVirgin Islands (McCreedy et al. 2006; Miller et al. 2006), the British Virgin Islands andMartinique (Ginsburg et al., unpublished data).

Our bleaching data corroborate the current trend of increasing geographical extent ofmass coral bleaching within the Caribbean basin and suggestion that coral bleaching islikely to be a chronic and significant source of stress for Caribbean reefs over this century(McWilliams et al. 2005). Given the already compromised resilience of many Caribbeanreefs to disturbances, as a result of their degraded state from anthropogenic impacts such asover-fishing and poor water quality (Rogers 1985; Hughes 1994; Wilkinson 2000; Gardneret al. 2003), the prediction that mass bleaching events will increase in frequency, and evenbecome a near annual event in the Caribbean by 2020 as a result of global warming(Hoegh-Guldberg 1999), has severe social and economic implications. This is particularlytrue for Barbados, where many nearshore reefs are already in a degraded state (Oxenfordet al. 1993; Government of Barbados 2002), and whose economy depends heavily on tourism(National Commission on Sustainable Development 2004). This serves to reiterate thevulnerability of small island states like Barbados, with a high reliance on healthy coral reefecosystem services, to elevated sea water temperatures associated with climate variabilityand global climate change, and emphasises the importance of continuing to press theinternational community for a strengthening of the Kyoto Protocol to reduce globalgreenhouse gas emissions. In the meantime, countries like Barbados need to take urgentpractical steps to improve effective management of their coral reefs to enhance resilience tomajor disturbances (Nystrom et al. 2000; Nurse and Moore 2005; Aronson and Precht2006; McClanahan et al. 2006). Further research to improve our understanding of resistanceto bleaching at a local scale (among reefs and taxa) and to identify reefs with attributes forhigh resilience (diverse well-balanced reef community, high larval supply and survival of

446 Climatic Change (2008) 87:435–449

coral recruits, good water quality) is needed to improve coral reef conservationmanagement in the face of increasing incidences of mass bleaching (West and Salm 2003).

References

Aronson RB, Precht WF (2006) Conservation, precaution, and Caribbean reefs. Coral Reefs 25:441–450Aronson RB, Precht WF, Toscano MA, Koltes KH (2002) The 1998 bleaching event and its aftermath on a

coral reef in Belize. Mar Biol 141:435–447Berkelmans R, De’ath G, Kininmonth S, Skirving WJ (2004) A comparison of the 1998 and 2002 coral

bleaching events on the Great Barrier Reef: spatial correlation, patterns, and predictions. Coral Reefs23:74–83

Brown BE (1997) Coral bleaching: causes and consequences. Coral Reefs 16:129–138Bruno JF, Siddon CE, Witman JD, Colin PI (2001) El Nino related coral bleaching in Palau, Western

Caroline Islands. Coral Reefs 20:127–136CARICOMP (1997) Studies on Caribbean coral bleaching, 1995–96. In: Proceedings 8th International Coral

Reef Symposium, Smithsonian Tropical Research Institute, Balboa, Panama, pp 673–678CARICOMP (2001) CARICOMP methods manual, levels 1 & 2: manual of methods for mapping and

monitoring of physical and biological parameters in the coastal zone of the Caribbean. CARICOMPData Management Centre, University of the West Indies, Jamaica, p 91

Edmunds PJ, Gates RD, Gleason DF (2003) The tissue composition of Montastraea franksi during a naturalbleaching event in the Florida keys. Coral Reefs 22:54–62

Fisk D, Done T (1985) Taxonomic and bathymetric patterns of bleaching, myrmidon reef (Queensland). In:Proceedings 5th International Coral Reef Symposium. Tahiti, French Polynesia, vol 6, pp 149–154

Gardner TA, Cote IM, Gill JA, Grant A, Watkinson AR (2003) Long-term region-wide declines in Caribbeancorals. Science 301:958–960

Glynn PW (1984) Widespread coral mortality and the 1982/83 El Nino warming event. Environ Conserv11:133–146

Glynn PW (1988) El Nino–Southern oscillation 1982–1983: Nearshore population, community, andecosystem responses. Ann Rev Ecolog Syst 19:309–345

Glynn PW (1993) Coral reef bleaching: ecological perspectives. Coral Reefs 12:1–17Glynn PW (2000) El Nino–Southern oscillation mass mortalities of reef corals: a model of high temperature

marine extinctions? In: Insalaco E, Skelton PW, Palmer TJ (eds) Carbonate platform systems:components and interactions, special publications 178. Geological Society of London, London, pp117–133

Glynn PW, Weerdt WHD (1991) Elimination of two reef-building hydrocorals following the 1982–83 ElNino warming event. Science 253:69–71

Goldberg J, Wilkinson C (2004) Global threats to coral reefs: coral bleaching, climate change, disease,predator plagues, and invasive species. In: Wilkinson C (ed) Status of coral reefs of the world: 2004, vol1. Australian Institute of Marine Science, Townsville, Australia, pp 67–92

Goreau TJ (1990) Coral bleaching in Jamaica. Nature 343:6257Goreau T, McClanahan T, Hayes R, Strong A (2000) Conservation of coral reefs after the 1998 global

bleaching event. Conserv Biol 14:5–15Government of Barbados (1999) The integrated coastal management plan for the West and South coasts of

Barbados. Coastal Zone Management Unit, Ministry of Health and the Environment, Government ofBarbados, Barbados, p 73

Government of Barbados (2002) A national biodiversity strategy and action plan for Barbados. Ministry ofPhysical Development and Environment, Government of Barbados, Barbados, p 155

Hoegh-Guldberg O (1999) Climate change, coral bleaching and the future of the world’s coral reefs. MarFreshw Res 50:839–866

Hoetjes P, Lum Kong A, Juman R, Miller A, Miller M, De Meyer K, Smith A (2002) Status of coral reefs inthe Eastern Caribbean: the OECS, Trinidad and Tobago, Barbados and the Netherlands Antilles. In:Wilkinson C (ed) Status of coral reefs of the world: 2002. Australian Institute of Marine Science,Townsville, Australia, pp 325–342

Hughes TP (1994) Catastrophes, phase shifts, and large-scale degradation of a Caribbean coral reef. Science265:1547–1551

Hughes TP, Baird AH, Bellwood DR, Card M, Connolly SR, Folke C, Grosberg R, Hoegh-guldberg O,Jackson JBC, Kleypas J, Lough JM, Marshall P, Nystrom M, Palumbi SR, Pandolfi JM, Rosen B,

Climatic Change (2008) 87:435–449 447

Roughgarden J (2003) Climate change, human impacts, and the resilience of coral reefs. Science301:929–933

Hunte W (2001) Environmental impact assessment of proposed limestone quarry expansion at Maycock’s–Bromfield, St.Lucy: final environmental impact statement. Report for Arawak Cement, Barbados, p 15

Hunte W, Vermeer LA, Goodridge R (1998) Temporal changes in coral reef communities on the West andSouth coasts of Barbados: 1987–1997. Technical Report for the Coastal Zone Management Unit of theGovernment of Barbados and the Inter-American Development Bank, p 142

Hunte W, Baldwin K, Goodridge R (2005) Temporal changes in coral reef communities on the West andSouth coasts of Barbados: 1987–2002. Technical Report for the Coastal Zone Management Unit of theGovernment of Barbados, p 138

Intergovernmental Panel on Climate Change (IPCC) (1996) Climate change 1995 – impacts, adaptation andmitigation of climate change: scientific–technical analyses – contribution of working group II to thesecond assessment report, Chapter 9. Cambridge University Press, Cambridge, pp 289–324

IPCC (2001) Climate change 2001, impacts, adaptation and vulnerability – contribution of working group IIto the third assessment report, Chapter 16. Cambridge University Press, Cambridge, pp 843–875

Lal M, Harasawa H, Takahashi K (2002) Future climate change and its impacts over small island states. ClimRes 19:179–192

Lang JC, Wicklund RI, Dill RF (1988) Depth- and habitat-related bleaching of Zooxanthellate reef organismsnear Lee Stocking Island, Exuma Cays, Bahamas. In: Proceedings 6th International Coral ReefSymposium. Townsville, Australia, vol 3, pp 269–274

Marshall PA, Baird AH (2000) Bleaching of corals in the central great barrier reef: variation in assemblageresponse and taxa susceptibilities. Coral Reefs 19:155–163

McClanahan TR (2004) The relationship between bleaching and mortality of common corals. Mar Biol144:1239–1245

McClanahan TR, Maina J (2003) Response of coral assemblages to the interaction between naturaltemperature variation and rare warm-water events. Ecosystems 6:551–563

McClanahan TR, Marnane MJ, Cinner JE, Kiene WE (2006) A comparison of marine protected areas andalternative approaches to coral-reef management. Curr Biol 16:1408–1413

McCreedy C, Miller J, Charles CW, Rogers CS (2006) Response to coral bleaching in U.S. Virgin IslandsNational Parks, US Geological survey – national parks service fact sheet, April 2006. Water ResourcesDivision, Denver, CO, p 2

McGrath TA, Smith GW (1998) The effects of the 1995/1996 Western Atlantic coral bleaching event on thepatch reefs around San Salvador Island, Bahamas. Rev Biol Trop Suppl 5:91–99

McWilliams JP, Cote IM, Gill JA, Sutherland WJ, Watkinson AR (2005) Accelerating impacts oftemperature-induced coral bleaching in the Caribbean. Ecology 86:2055–2060

Miller J, Waara R, Muller E, Rogers C (2006) Coral bleaching and disease combine to cause extensivemortality on reefs in US Virgin Islands. Coral Reefs 25:418

Mumby PJ, Chisholm JRM, Edwards AJ, Clark CD, Roark EB, Andrefouet S, Jaubert J (2001)Unprecedented bleaching-induced mortality in Porites spp. at Rangiroa Atoll, French Polynesia. MarBiol 139:183–189

National Commission on Sustainable Development (2004) National sustainable development policy forBarbados. Ministry of Housing, Lands and the Environment, Government of Barbados, Barbados, p 52

Nurse L, Moore R (2005) Adaptation to global climate change: an urgent requirement for small islanddeveloping states. RECIEL 14:100–107

Nystrom M, Folke C, Moberg F (2000) Coral reef disturbance and resilience in a human-dominatedenvironment. Trends Ecol Evol 15:413–417

Oliver J, Marshall P, Setiasih N, Hansen L (2004) A global protocol for assessment and monitoring of coralbleaching. WorldFish Centre, Pelang, Malaysia, p 38

Oxenford HA, Vermeer LA, Wittenberg M (1993) Nearshore benthic marine communities of the West andSouthwest coasts of Barbados: importance, present status and management recommendations, Report forDELCAN, Toronto, Canada/Coastal Conservation Project Unit, Government of Barbados, p 137

Pockley P (1999) Global warming could kill most coral reefs by 2100. Nature 400:98Reaser JK, Pomerance R, Thomas PO (2000) Coral bleaching and global climate change: scientific findings

and policy recommendations. Conserv Biol 14:1500–1511Rogers CS (1985) Degradation of Caribbean and Western Atlantic coral reefs and decline of associated

fisheries. In: Proceedings 5th International Coral Reef Symposium, Tahiti, French Polynesia, vol 6, pp491–496

Smith AH, Archibald M, Bailey T, Bouchon C, Brathwaite A, Comacho R, George S, Guiste H, Hastings M,James P, Jeffrey-Appleton C, De Meyer K, Miller K, Nurse L, Petrovic C, Philip P (2000) Status of coralreefs in the Eastern Caribbean: the OECS, Trinidad and Tobago, Barbados, the Netherlands Antilles and

448 Climatic Change (2008) 87:435–449

the French Caribbean. In: Wilkinson C (ed) Status of coral reefs of the world: 2000. Australian Instituteof Marine Science, Townsville, Australia, pp 315–330

Spencer T, Teleki KA, Bradshaw C, Spalding MD (2000) Coral bleaching in the Southern Seychelles duringthe 1997–1998 Indian Ocean Warm Event. Mar Pollut Bull 40:569–586

Wellington GM, Glynn PG, Strong AE, Nauarrete SA, Wieters E, Hubbard D (2001) Crisis on coral reefslinked to climate change. EOS Trans 82:1–7

West JM, Salm RV (2003) Resistance and resilience to coral bleaching: implications for coral reefconservation and management. Conserv Biol 17:956–967

Wilkinson CR (1996) Global change and coral reefs: impacts on reefs, economies and human cultures. GlobChang Biol 2:547–558

Wilkinson CR (ed) (2000) Status of coral reefs of the world 2000. Australian Institute of Marine Science,Townsville, Australia, p 363

Williams EH Jr, Bunkley-Williams L (1988) Bleaching of Caribbean coral reef symbionts in 1987–1988. In:Proceedings 6th International Coral Reef Symposium, Townsville, Australia, vol 3, pp 313–318

Winter A, Appeldoorn RS, Bruckner A, Williams EH Jr, Goenaga C (1998) Sea surface temperatures andcoral reef bleaching off La Parguera, Puerto Rico (Northeastern Caribbean Sea). Coral Reefs 17:377–382

Climatic Change (2008) 87:435–449 449