February 2012 Expedition - Day 6 - The most perfect corals I’ve ever seen

Diving on the seaward side of the Salomons atoll today was described  by Heather, one of the scientists here, as emotional.  She said “they were the most perfect corals I’ve ever seen and I wish that more of the world’s reefs looked like this”.

The corals are thriving and the coral cover is high, probably as high as it has ever been.  And there are painfully few places in the world where that is the case.

The newest satellite images show that the threat of a damaging warming event for the whole western and central Indian Ocean region has passed for this year.  In Chagos, the main threat to coral reefs is increasing seawater temperature.  This morning we recovered and replaced temperature recorders in the lagoon at Salomons Atoll, as we did in Diego Garcia a couple of days ago.  These have been placed around the archipelago, at other atolls not yet visited as well,  to monitor sea temperature at two hourly intervals.  This is an ongoing programme, and is invaluable to tell us not only what the temperatures are, but to better calibrate the data obtained from the coral cores which are used to give historic seawater and climate information.  It’s always a relief to get to the site and be able to find the recorder, and a relief to find the led light still happily blinking.

Catherine and Heather’s work involves collecting and examining the cryptofauna which inhabit dead coral heads.  The buckets with the samples awaiting processing live in the ladies toilet on board the ship until processing, which takes until well into each night.  These small organisms are usually overlooked and until now have not been studied in Chagos.  These organisms are the basis of a network of different  food chains and are also important in bioerosion – the process by which corals are turned into sand and continue the cycle through the reef.