AN ASSESSMENT ON THE AN ASSESSMENT ON THE EFFECTS OF THE EFFECTS OF THE TSUNAMI ON THE TSUNAMI ON THE

MALAYSIAN CORAL REEFSMALAYSIAN CORAL REEFS

Zulfigar Yasin, Anisah Lee and Zulfigar Yasin, Anisah Lee and Aileen TanAileen Tan

Centre for Marine And Costal Centre for Marine And Costal StudiesStudies

Universiti Sains MalaysiaUniversiti Sains Malaysia

Location of North Location of North Malaysian coast affected by Malaysian coast affected by

the Tsunamithe Tsunami

Landsat Thematic Mapper image of the coastal region of North Peninsular Malaysia

HABITAT CLASSES

Permanent shallow marine waters (5 m depth contour)

Intertidal mudflats

Mangrove Reclaimed land

Coral reefs Rocky shore

Seagrass bed Sandy shore

Manmade island

LANGKAWI ISLANDS

PAYAR ISLANDS

SONGSONG ISLANDS

PENANG

ALOR SETAR

Kuala Kedah

Merbok

Kota Kuala Muda

Butterworth

Muka Head Marine Research Station USM

North

STRAITS OF MALACCA

Scale 1:80 000

Georgetown

Existing Coastal Habitats

LANGKAWI ISLANDS

PAYAR ISLANDS

SONGSONG ISLANDS

PENANG

ALOR SETAR

Kuala Kedah

Merbok

Kota Kuala Muda

Butterworth

MukaHead Marine Research Station USM

North

STRAITS OF MALACCA

Scale 1:80 000

Sg. Aceh

Sg. Muda

Sg. Merbok

Sg. Kedah

Sg. Udang

Pu. Kendi

Balik Pulau

Tk. Bahang

Bt. Feringghi

Pu. Singa BesarPu. Beras Basah

Pu. Segantang

Pu. Payar

Pantai Chenang

Pantai Kok

Tg. Malai

Areas of tsunami impact

Muka Head Marine Research StationMuka Head Marine Research Station

Universiti Sains MalaysiaUniversiti Sains Malaysia

Research on the Seas and Islands of Malaysia (ROSES) - Voyage Route 2004

LEGEND

SECTION 1

SECTION 3

Pre-tsunami image

Subset

Study Area

Masking

Pre-tsunami Coastal Area

Atmospheric correction

Pre-tsunami coastal area

Supervised Classification

Supervised Classification Pre-

tsunami Coastal Habitat MapArchival data

(ROSES etc)Accuracy

Assessment

High Accuracy (>75%)

Map Composition Output:

Pre-tsunami Coastal Habitat Classification Map

Reclassification

Low Accuracy (75%)

Post-tsunami image

Subset

Study Area

Masking

Post-tsunami coastal area

Atmospheric correction

Post-tsunami coastal area

Supervised Classification

Supervised Classification Post-

tsunami Coastal Habitat Map

Groundtruthing data

Accuracy Assessment

Low Accuracy ( 75%)

Map CompositionOutput:

Post-tsunami Coastal Habitat Classification Map

High Accuracy (>75%)

Final Output:

Coastal Habitats Affected by Tsunami

Change Detection Analysis

Image Pre-processing Phase

Image Processing Phase

New survey data

Coral reefs – offshore Coral reefs – offshore islandsislands

Offshore reefs islands Offshore reefs islands surveyedsurveyed

Evidence unlike that of Evidence unlike that of large storm damagelarge storm damage

Erosion on reef tops Erosion on reef tops especially the reef especially the reef edgeedge

Sediment resuspension Sediment resuspension and damage to fragile and damage to fragile coral skeletonscoral skeletons

Fringing reefsFringing reefs

Deeper water reefs Deeper water reefs less affectedless affected

Shallow and intertidal Shallow and intertidal reefs most affectedreefs most affected

Evidence of Evidence of secondary effects of secondary effects of tsunami already seentsunami already seen

Stress monitoring Stress monitoring underwayunderway

Sea grass beds and Sea grass beds and mudflatsmudflats

Mudflats and Mudflats and coastal sandy coastal sandy beaches show beaches show change in beach change in beach profileprofile

Changes in animal Changes in animal community profile community profile

Epifauna affected Epifauna affected Indication of Indication of

community changescommunity changes

Sea condition Sea condition three hoursthree hours after the tsunami event - after the tsunami event -

ebbing tideebbing tide

Sea condition - Sea condition - 8 minutes 8 minutes laterlater

Fish kill a day after the tsunami Fish kill a day after the tsunami eventevent

Remains of fishermen’s Remains of fishermen’s aquaculture cages in Penang - 3 aquaculture cages in Penang - 3 hours after the tsunami eventhours after the tsunami event

Largest change of generic reef Largest change of generic reef types between the SCS and the types between the SCS and the

Indian OceanIndian Ocean

Some salient pointsSome salient points Important not to Important not to generalisegeneralise impacts impacts Pre-tsunami dataPre-tsunami data and ecological behaviour critical and ecological behaviour critical

in assessmentin assessment ImmediateImmediate post tsunami monitoring important for post tsunami monitoring important for

effects not to be maskedeffects not to be masked Assessment must have a Assessment must have a predictive valuepredictive value and and

therefore detail scientific assessment importanttherefore detail scientific assessment important Devastation in Acheh reefs and Malaysian offshore Devastation in Acheh reefs and Malaysian offshore

islands mostly unknownislands mostly unknown Immediate need to set up post tsunami assessment Immediate need to set up post tsunami assessment

specifically for coral reefs in the impacted areas of specifically for coral reefs in the impacted areas of Malaysia, Thailand and IndonesiaMalaysia, Thailand and Indonesia