How does rising atmospheric CO2 affect marine organisms?

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Atmospheric DMS in Relation to Local Coral Cover
Jones, G.B. and Trevena, A.J.  2005.  The influence of coral reefs on atmospheric dimethylsulphide over the Great Barrier Reef, Coral Sea, Gulf of Papua and Solomon and Bismarck Seas.  Marine and Freshwater Research 56: 85-93.

On the basis of measurements of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) made on mucus ropes, coral mucus, surface films and sediment pore waters associated with corals of Australia's Great Barrier Reef (GBR), Broadbent and Jones (2004) concluded that "coral reefs in the GBR are significant sources of these two sulphur substances" that figure prominently in the CLAW hypothesis of biologically-mediated climate buffering.  Jones and Trevena test another aspect of this phenomenon by exploring the relationship between atmospheric DMS concentration and nearness to locations of significant coral cover in the same general area and surrounding regions.

What was done
During a winter voyage through the northern GBR, Coral Sea, Gulf of Papua (GOP), and Solomon and Bismarck Seas, measurements were made of dissolved DMS, DMSP, the water-to-air flux of DMS, and atmospheric DMS concentration.

What was learned
The authors report that the "highest levels of most of these constituents occurred in the northern GBR, NW Coral Sea and GOP, with highest levels of atmospheric DMS often occurring in south-easterly to southerly trade winds sampled in the region where the highest biomass of coral reefs occur."  They also found that the increase in atmospheric DMS "was mainly a result of a combination of high winds and the extremely low tides in July, when a high biomass of coral reefs in this region was aerially exposed."

What it means
This research solidifies the link between coral zooxanthellae activity and the atmospheric concentration of DMS, which Broadbent and Jones (2004) call "a negative greenhouse gas," i.e., one whose presence tends to cool the planet.  Hence, it broadens the base of the CLAW hypothesis and makes it ever more likely that that hypothesis represents a viable mechanism for tempering, and possibly even capping, global warming.

Broadbent, A.D. and Jones, G.B.  2004.  DMS and DMSP in mucus ropes, coral mucus, surface films and sediment pore waters from coral reefs in the Great Barrier Reef.  Marine and Freshwater Research 55: 849-855.

Reviewed 6 April 2005