Expedition Saba Bank: First week done. Highlights.

24 October 2015
Erik Meesters Expedition leader first week

Divers hanging on line and waiting to be picked up
while being watched by sharks

Well the first week is behind us. Part of the team has now left and we have a couple of new people on board to help with the next part.The expedition went very well. We were able to do everything we had planned and more. The Dutch navy was able to put in the two new moorings, so we now we can stay the night over on the Bank without anchoring. This is very good, because that way we will not cause any damage to the reef.

We also explored a new part of the bank that appeared very rich in terms of coral cover and fish density. In many places we found large groupers and together with the large number of sharks this seems to indicate that the bank is in a relatively good condition.

Yellowfin Groupers closely followed by a trumpet fish on the
Saba Bank

We had very calm weather which helped enormously to get things done. Normally, wave are easily 2-3m high, but this year there only was a little rippling over the bank. Maybe this is related to the El Nino event  which is causing strange and unpredictable weather patterns all over the world. For the marine life it can be devastating. Some animals travel half way across the globe to rich waters and an El Nino may change current patterns and upwelling areas may not turn into the highly productive systems that animals expect or just turn into the opposite.

For corals an el nino may lead to warm water and to bleaching, the loss of the unicellular symbiotic algae from the tissue of the corals. As a consequence the coral appears white because the underlying white skeleton is shining through. The animal is not yet dead, but this is likely to happen if the warm water temperatures last for more than a week.

A coral (Porites astreoides)  that is partly bleached.

What exactly will happen is difficult to predict. Sea currents are among the most difficult things to predict. Let's hope sea water temperatures will quickly return to normal and that the damage to the Saba Bank coral ecosystem will be minimal. Since corals generally are very slow growing, an intense bleaching episode may need a few decades of recovery. There are indications that healthy corals bleach less, and reports from Gouadeloupe are already speaking of severe bleaching while here on the Saba Bank we only saw a few bleached corals. This seems to indicate that corals in general are healthy on the Saba Bank and may be some reasons for optimism for the Saba Bank coral reef ecosystem.