Status of Coral Reefs in Thailand

• Around 280 species ofscleractinian corals were recorded• Coral specimens were collectedat the reference collection atPhuket Marine Biological Center

Coral reef fish visual censusTotal ~ 960 species

Coral reef macro-benthos

Distribution of coralreefs in ThailandRanong1.7%cholburi5%Rayong 2.3%Chantaburi0.5%Prachuab 1.3%Trad10.4%Chumporn 4.3%Suratthani25.3%Andaman Sea~ 50%(~ 80 km 2 )Phang-nga16.4%Phuket10.9% Krabi 8.8%Trang2.9%Satul10.3%Gulf ofThailand~ 50%(~ 80 km 2 )

Coral reef map showingreef condition on the reefedge-slope zone of theislands(results from manta-tow survey)very healthyhealthyfairpoorVery poor(The surveys throughout Thailand were repeated in every about 5 years)

Status of coral reefs inThailand (2006 – 2008)CBR13.827.2RY12.1very healthyhealthyfairpoorvery poorJTR2819PJBTRDAndamanSeaRNCP22.47.114.4PNGSRvery healthyhealthyfairpoorvery poor26.329.8PKKBGulfTRST

Trend of change in aboutthe past decade

Status of coral reefs in the Andaman Sea23.34.61213.827.2very healthyhealthyfairpoorvery poor12.1very healthyhealthyfairpoorvery poor33.626.528191995-1998 2006-2008

Status of coral reefs in the Gulf of Thailand12.916.422.47.114.410.929very healthyhealthyfairpoorvery poorvery healthyhealthyfairpoorvery poor30.826.329.81995-1998 2006-2008

IndianOceanThailandNorth - offshoreCentral - nearshoreA case in theAndaman SeaSouthern - offshoreLine InterceptTransect study sitesare grouped into 3regions

Data collected from permanently marked transects on theupper reef slopes at 60 locations reveal four basic temporalpatterns37% reef sites damaged from environmental factors followed bygood recovery23% reef sites showing damage and little or no recovery33% reef sites unaffected, with live cover either remaining stable orsteadily increasing until present7% reef sites damaged by the tsunami and are predicted to showrecovery within the next 5-10 years if conditions remainfavourable for reef growth

Data collected from permanently marked transects on theupper reef slopes at 60 locations reveal four basic temporalpatterns37% reef sites damaged from environmental factors followed bygood recovery23% reef sites showing damage and little or no recovery33% reef sites unaffected, with live cover either remaining stable orsteadily increasing until present7% reef sites damaged by the tsunami and are predicted to showrecovery within the next 5-10 years if conditions remainfavourable for reef growth

tsunami impact in2004(Andaman Sea)

Impact on coral reefs (n=174)9%13%40%No impactVery low( 50% of live corals are damaged)

% covernumber of s peciestsunamitsunamilive coral cover (%)403530252015105036132005 2010year302520151050species richnessCoral species richness28172005 2010yearLive coral cover and coral speciesrichness on the SW of Mai Pai Island(~1 month and ~5 years after tsunami)

% covertsunami%cover of E chinopora lamellosa20151050191.92005 2010yearEchinopora lamellosathe most successful inrecolonizing the reef onSW Mai Pai Island

% covernumber of s peciestsunami tsunamilive coral cover (%)60504030201005440322001 2005 2010yearspecies richness40353025201510503723252001 2005 2010year2010Live coral cover and coral speciesrichness on the SE of Tachai Island

% cover302520151050% cover of Porites (Synaraea) rus271552001 2005 2010yearPorites rusthe most successful inrecolonizing the reef onSE Tachai Island

Acropora clathrataPorites luteaRegrowth oftsunami-damaged corals(2 years after tsunami)

Tachai 2010new recolonized coral5 –year-new growth

Impact from theIndian Ocean DipoleMay 1994 until Jan 1995 andJuly 1997 until May 1998TOPEX/POSEIDON satellite altimeter records

West Indian Ocean•High sea level•Lowered thermocline•Reduced upwellingE-Indian Ocean•Sea level depressed•Thermocline raised•Cool upwellingIndian Ocean Dipole May 1994 until Jan 1995 and July 1997 until May 1998

Soft corals and many species of reeffauna died off due to cool upwelling,with very low dissolved oxygen

Severe crown-of-thornsstarfish infestation during1984-1986 (Andaman Sea)(patchy occur– during 2007-2010)

Impact from diving tourism

Sedimentation from landdevelopment

Temperature (c)33.53432.53331.53230.53129.53028.52927.52826.52725.52624.52524Temperature at Phuket 2008-201018/6/08 2/8/08 17/9/08 1/11/08 16/12/08 30/1/09 16/3/09 1/5/09 15/6/09 30/7/09 13/9/09 26/12/09 9/2/10 26/3/10 9/5/10DATEApril-May201020107/6/10sea surface temperature atPhuket during 2008-2010Coral bleaching in2010~ 80% of corals bleached oneach reef throughout everyprovince along the AndamanSea and the Gulf

In areas where environmental factors are good and coral diversityis high, with large numbers of colonies, corals are usuallypartial bleached. Some normally coloured colonies are found atthese sites.

EastWestIn the Andaman Sea, the reefs on the east coast of the islands aremore impacted than on the west. On the west sides of islands,which are subject to internal waves and generally strongerwave action, the reefs may show partial bleaching (or slightpaling)

In turbid areas where the water flowis high, many coral colonies can resist bleaching.This is probably due to the acclimatization andadaptation of corals to extreme environmentalconditions.Also, light penetration through the water column isdecreased at these sites thus reducing thecombined temperature/light stresses that inducebleaching.

Pavona decussataDiploastrea helioporaVery few coral species have been found which resist bleachingPorites lutea coloniesfrequently show partialbleaching (with apicalsurfaces being normallycoloured while the sides arebleached).

Mortality rates of between 5-40% were alreadyreported at the end of May

Status of coral reefs in Thailand (2006 – 2008)13.8Andaman Sea27.222.47.1Gulf of Thailand14.412.1very healthyhealthyfairpoorvery poorvery healthyhealthyfairpoorvery poor281926.329.8

Status of coral reefs in Thailand (2006 – 2008)13.8Andaman Sea27.222.47.1Gulf of Thailand14.412.1very healthyhealthyfairpoorvery poorvery healthyhealthyfairpoorvery poor281926.329.8Big change after 2010 coral bleaching??

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