Aileen Tan S. H. Mohammad Reza M. Cherrie Teh C. P. Nithiyaa N. Norhanis R. Zulfikar Nadras O. Zulfigar Y.

Transcription

1 Aileen Tan S. H. Mohammad Reza M. Cherrie Teh C. P. Nithiyaa N. Norhanis R. Zulfikar Nadras O. Zulfigar Y.

2 Pulau Weh, Indonesia Lhok Pria Laot Bay Last volcanic activity in the island occurred in Pleistocene, which forms the hydrothermal vent at the Lhok Pria Laot Bay in Pulau Weh.

3 Sampling transects: parallel and perpendicular to the shore were established Parameters measured includes: ph of seawater live coral coverage coral genus composition ph of seawater was measured during: wet (October 2012) and dry season (May 2013)

4 October 2012 Wet Season May 2013 Dry Season

5 Wet season (Oct 2012) Range of ph : Dry season (May 2013) Range of ph :

6 Longitude D C B A Latitude

7 Station A ph: 7.21 Station B ph: 7.31 Station C ph: 7.50 Station D ph: 7.83

8 Average of area coverage of live coral (m 2 ) Association between average live coral cover and ph R² = ph

9 Percentage cover (%) Percentage of live coral cover at Lhok Pria Laot Bay, Pulau Weh Others Coral Rubble Macroalgae Sand Dead Coral Live Coral 0.0 A B C D ph: 7.21 ph: 7.31 ph: 7.50 ph: 7.83 Station Increasing distance away from the hydrothermal vent

10 Number of coral genus Longitude Changes in coral genus along the ph gradient Symphillia Porites Pectinia Montastrea Massive coral 3 Massive coral 2 Massive coral 1 Goniastrea D C B A Favites Favia Encrusting coral 3 Encrusting coral 2 Encrusting coral 1 Diploastrea Caulastrea Branching coral 1 Latitud e 0 Station A Station B Station C Station D ph: 7.21 ph: 7.31 ph: 7.50 ph: 7.83 Acropora Increasing distance away from the main vent

11 Association between number of coral genera and ph in the Straits of Malacca ph * White area: no data

12 Pulau Weh, Indonesia (Andaman Sea) Pulau Bidong UMT Marine Research Station, Malaysia (West South China Sea) Permanent monitoring sites for coral health and ocean acidification Pulau Langkawi, Malaysia (Straits of Malacca) TAR Marine Park, Sabah (East South China Sea)

13

14 Pulau Weh, Indonesia Site Control Thermal Vent (300m from source) Description Thermal Vent (200m from source) Thermal Vent (Source) Mean ph Mean salinity Salinity range 30.3 ppt 34.5 ppt 33.4 ppt 33.9 ppt ppt ppt ppt ppt

15 Shell Morphology Control Thermal Vent (300m from source) Thermal Vent (200m from source) Thermal Vent (source)

16 X-ray diffraction showing the crystalline phase-formation affected by ph Control Thermal Vent (200m from source) Thermal Vent (300m from source) Thermal Vent (source) The analysis of crystal structure using XRD shows that the main peak appeared at 2 theta were from 29 C to 31 C The main peaks in all samples from different areas correspond to a limestone peak or known as Calcium carbonate, CaCO 3.

17 X-ray fluorescene spectroscopy analysis showing the mineral composition in shells affected by ph The finding demonstrates that oyster shells from different study locations were made up of calcium (92-93%). Percentage of component in shell (%) Compound Control 200m from source 300m from source Thermal vent (source) CaO LOI MgO SO

18 Scanning electron microscopy showing the microstructure of the oyster shells Pulau Weh, Indonesia Site Control Thermal Vent (200m from source) Thermal Vent (300m from source) Thermal Vent (source) SEM of oyster shells Mean ph

19 South East Asia in the tropics

20

21 Between 2005 and 2012, Thailand, Malaysia and Vietnam s shellfish industries suffered disastrous production losses Some experienced 100% mortality of bivalve culture especially mussel culture Is ocean acidification the culprit?

22 Hatchery-Produced Oyster Seeds Site with normal ph Site with lower ph Crassostrea iredalei PARAMETERS MEASURED Survival Growth Feasibility to reproduce Crassostrea belcheri

23 Site Normal ph Lower ph Mean ph Mean salinity 30.3 ppt 20.5ppt RESULTS Both Crassostrea belcheri and Crassostrea iredalei are able to tolerate acidic environment SURVIVAL (%) CI CB GROWTH CI / CB Faster Slower Oysters at Site B showed higher survival, but no significant differences compared to Site A Shell thickness Thick Thin REPRODUCTION FECUNDITY CI / CB

24 Percentage of survival (%) Broodstock from Site with lower ph : Broodstock Larvae were from able Site to with survive in ph as normal low ph as 7.2 : Larvae although unable the percentage to survive survival well reduced in ph lower from ph 7.6 to 7.2 than Broodstock from Site A Site B ph Note : Survival at pediveliger stage

25 Percentage of settlement Crassostrea iredalei Crassostrea belcheri 25 ppt Settlement would not be affected by different ph levels if the optimum salinity is given 20 during the 18 settlement ppt stage 0 Larval Larval settlement settlement of broodstock of broodstock from from Site Site with with normal lower ph ph was showed lower than no significant Site with lower differences ph at between ph ph 7.8 from 7.6 to ph Broodstock from Site A Site B No settlement experiment was conducted at these ph levels because of high mortality during the larval stage

26 Biophysical effects Effects on calciferous animals eg. molluscs, crustaceans, corals, echinoderms and some phytoplankton Complicated Responses Acclimation? Adaptation? Depending on: Species Populations Different life stages etc.

27 Local organizing committee IOC/WESTPAC Mr. Wenxi Zhu Phuket Marine Biological Station