How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Maldivian Reefs: Fighting Back from Near Oblivion
Lasagna, R., Albertelli, G., Giovannetti, E., Grondona, M., Milani, A., Morri, C. and Bianchi, C.N. 2008. Status of Maldivian reefs eight years after the 1998 coral mass mortality. Chemistry and Ecology 24: 67-72.

The 1998 bleaching episode caused by the strong El Niņo of that year severely affected most Indian Ocean reefs, with the Maldives suffering 90% coral mortality in their central atolls. Prior to this mass mortality, the authors write that "hard coral cover was generally between 30 and 60%, often reaching 100% in shallow water." One year later, however, they report that "coral cover had decreased to less than 8%, and reefs were dominated by algae."

What was done
In April of 2006, Lasagna et al. "re-examined the status of the Maldivian reefs, focusing on their benthic composition to evaluate the possible change in dominance from hard corals to non-constructional organisms such as soft corals, algae or sponges," which are often predicted by climate alarmists to replace hard corals after major bleaching episodes.

What was learned
The seven Italian scientists report that "eight years after the 1998 coral mass mortality, hard coral cover varied from 12% to 37%," and that "cover of soft corals, algae and sponges was comparatively low (approximately 7% on average)." In addition, they say that "a recent inventory of coral species showed that their number is larger [our italics] than that known before 1998 (Pichon and Benzoni, 2007)."

What it means
The ongoing process of re-colonization by hard corals in the central atolls of the Maldives is off to an amazingly good start; and Lasagna et al. note that "continued monitoring of reef recovery is in progress," with the goal of accurately tracking their future evolution. So far, therefore, we can say so good!

Pichon, M. and Benzoni, F. 2007. Taxonomic re-appraisal of zooxanthellate scleractinian corals in the Maldive Archipelago. Zootaxa 1441: 21-33.

Reviewed 3 June 2009