Local Acidification Research on a fringing reef at the east coast of Hainan Island, Northern Sounth China Sea Chemistry Group: Xu Dong, Haining Huang Hydrology Group: Aijun Pan, Junpeng Zhang Gene Group: Mingliang Chen, Zhenyue Lin Third Institute of Oceanography, State Oceanic Administration, China Funded by the TIO basic science and research programs (NO. 21413)
WHY Ocean Acidification (OA): Anthropogenic CO2 emission Local Acidification (LA): River (Salisbury et al., 28), Upwelling (Feely et al., 28), Eutrophycation (Cai et al., 211), Growndwater (Wang et al., 215) etc. seawater OA long term sensitive seawater LA short term
Study area Coastal upwelling Rivers Coral reefs distributing inshore
WHAT WE DO BY NOW Weak Strong Temperature D3 Climate (2~213) 3 Temperature anomaly D3 El Nino (22 29) 1.5 Temperature anomaly D3 La Nina (28 21) 1.5 2 4 25 29 28 27 26 2 4 1.25 1.75 2 4 1.25 1.75 Depth [m] 6 8 1 12 14 2 25 24 23 22 21 2 19 Depth [m] 6 8 1 12 14.5.25 -.25 -.5 Depth [m] 6 8 1 12 14.5.25 -.25 -.5 16 21 o N 2 o N Q1 18 19 o N D3 19 o E 111 o E 113 o E 2 5 1 Position along the Section [km] 15 18 17 16 15 14 16 18 El Niño 2 5 1 Position along the Section [km] -.75-1 -1.25-1.5 16 18 La Niña 2 5 1 Position along the Section [km] -.75-1 -1.25-1.5 Response of coastal upwelling to ENSO
Precipitation data from Qionghai weather station ENSO index data originate from Climate Prediction Center, NOAA WHAT WE DO BY NOW El Niño: strong 1953-213 record La Niña: weak Temporal evolution of the correlation between the seasonal precipitation and the seasonal ENSO index.
WHAT WE HAVE KNOWN Weak upwelling and strong river discharge may be possible dominant during El Niño, whereas strong upwelling and weak river discharge tend to be prevailing during La Niña. UNKNOWN AND NEXT PLAN How linking ENSO to local acidification?
WHAT WE DO BY NOW Surface distribution of DIC, TAlk, ph25 and ΩAr are shown in Fig.. DIC varied from 185 μmol/kg-194 μmol/kg during 214 cruise and 1921 μmol/kg-1963 μmol/kg during 215 cruise. TAlk varied from 237 μmol/kg-224 μmol/kg during 214 cruise and 2198 μmol/kg- 2233 μmol/kg during 215 cruise. The variations of DIC and TAlk generally followed salinity with lower values appearing in diluted waters. ph 25 changed from 8.31-8.75 during 214 cruise and 7.995-8.57 during 215 cruise. Ω Ar changed from 2.77-3.5 during 214 cruise and 2.95-3.35 during 215 cruise. Waters with the lowest ph 25 and Ω Ar were located at Tanmen reef station during 214 cruise and they were located at both Tanmen reef station and Changqi reef station during 215 cruise. Of note, Tanmen reef station and Changqi reef station are closest to rivers.
WHAT WE DO BY NOW The distributional patterns of DIC, TAlk, ph 25 and Ω Ar displayed overall isolines climbing to the shore along the bottom which may be as a result of seasonal upwelling during cruises, The isolines of DIC, TAlk, ph 25 and Ω Ar are more tilting upward and coastward during 215 cruise.
WHAT WE HAVE KNOWN A river plume and coastal upwelling are major features in summers of 214 and 215 at the east coast of Hainan Island, which is jointly influencing the dynamics of carbonate system. Our observations display a river plume and coastal upwelling directly carried acidic waters to a fringing reef at the east coast of Hainan Island during cruises. UNKNOWN AND NEXT PLAN How impacts of local acidification mediated by river and upwelling on reef waters. What's the mechanism of LA influencing a fringing reef.
WHAT WE DO BY NOW Galaxea fascicularis a dominant species of corals -2 ).15-1 m.1 in m o l m (m G.5. 8. 7.7 ph25 (Total scale) Response of Biocalcification to Acidification Percentage of coral (G. fascicularis) and Symbiodinium origin of unigenes in the the transcriptome Distribution of GC contents of the assembled sequences
WHAT WE HAVE KNOWN We have known the dominant species Galaxea fascicularis in our study area may be insensitive to OA. And we successfully separated the transcriptomes between coral host and Symbiodinium. UNKNOWN AND NEXT PLAN How genes of corals response to LA. How responses of symbiosis between coral host and symbiodinium to LA.
Future work 1 Long-term obsevation 2 Using ARMS, CAUs, and BMUs
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