Reef-status on Maldives
t.flueck at nzz.ch
Wed Jul 22 18:44:06 EDT 1998
>From July 3 to 18 we investigated maldivian coral reefs in the north of the Ari atoll. When we arrived there, bleached corals could already be seen from the plane. When we left the archipelago two weeks later, bleached corals could hardly be observed from this bird's-eye view.
In between we checked seven reefs, using 100 meter transect lines in 4 and 10 m depth. According the methods of Reefcheck98 we recorded the substrate. The provisional results are sad: More than 95% of all hard corals (mostly Acropra sp.) were dead and covered with algae. Porites sp. colonies were bleached up to 100%. All Fungia and Herpolita were bleached. Leather corals e.g. Sinularia sp. were bleached up to 100%. Sea-anemones were bleached as well... and so on.
Below a depth of 15 m living colonies were found here and there.
During the investigations the number of bleached corals decreased whereas the number of algae-covered colonies increased. The degree of filamentous algae- and siltation-covering increased rapidly.
The same situation is reported from 6 other teams working on North- and South-Male atoll in the same period.
Here are the questions we would like to post:
1. Is it reasonable to assume that large scale factors as global-warming and CO2-increase brought these systems to a critical point and that local factors as eutrophication (probably due to increasing number of tourist resorts) tilt them?
2. How do you rate the chance for these reefs to recover?
3. If there is a chance for recovery, how long does it take?
4. Do you know references describing similar situations?
We look forward to hearing your comments.
Dipl. phil. II
Editor NZZ Online (http://www.nzz.ch)
Neue Zuercher Zeitung
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