Friday, October 31, 2014
We wrapped up our last night of sampling doing some night measurements of bleached and pigmented colonies of Porites compressa. We were at a land-based site thankfully (!) but it was still unnerving having the instrumentation precariously situated on a rock wall with crashing waves below. Here is Tong operating the instrument and taking notes of the sampling times by flashlight, while Colleen is wading below holding the instrument (keeping it from falling into the ocean) and Amy snorkeling in the water holding the tubing at the coral surfaces (while waves are crashing over her!). Despite the craziness, we obtained beautiful nighttime superoxide measurements from the corals! What a way to end the trip!
Wednesday, October 29, 2014
We have had a busy few days (hence the lack of updates). During this time, we've hit our stride and optimized the instrumentation for making in situ superoxide measurements. Despite a few hiccups here and there, we have had remarkable success in making these measurements! The data are better than we had expected or even hoped for! We have measured superoxide concentrations from both bleached and pigmented colonies of five different coral species, Porites compressa, Porites lobata, Montipora capitata, Pocillopora damicornis, and Fungia scutaria, from five different reefs. The depth of corals has ranged from less than a foot to up to 5 feet. We have a lot of data modeling ahead of us!
Saturday, October 25, 2014
Thursday, October 23, 2014
|"Can this be my office everyday?"|
Today was our first day out on Kaneohe Bay conducting superoxide measurements on bleaching and non-bleaching corals. We packed up our gear, loaded it on the boat and headed out into the beautiful bay. We settled on a site and Colleen and Tong got to work setting up the instrument while Laura and Amy scouted out potential corals. Although in theory everything should work just as well as yesterday, we were all a bit jittery about all of the unknowns, including waves, a moving boat, and the occasional shark cruising by (well, at least those of us in the water had that on our mind). Our jitters soon evaporated as the data starting rolling in and we were detecting superoxide from corals! We had a very successful day, and measured superoxide fluxes from many corals on two separate reefs.
|Measuring superoxide on shallow coral reefs.|
Wednesday, October 22, 2014
Our team consisting of Woods Hole Oceanographic Institution scientists Colleen Hansel, Amy Apprill, post-doc Tong Zhang and graduate student Laura Weber arrived in Oahu, Hawaii. We are staying at the Hawaii Institute of Marine Biology (HIMB), part of the University of Hawaii, located on Coconut Island. Today we were warmly welcomed by the scientists, and learned of the enormous amount of research and effort by HIMB and other local scientists on the bleaching event.
Today we needed to test out our equipment and approach before we packed up everything and took it out on the boat. We found some corals residing off the Point Lab at HIMB that were shallow enough for us to measure. Fortunately, we were able to get measurements on a few corals before the rain hit. We didn’t have time to move the gear before a rainstorm approached, so we held trash bags over it while we weathered the storm and dreamed of developing a waterproof instrument.
Tuesday, October 21, 2014
|We are conducting our research on the corals bleaching in Kaneohe Bay, Oahu.|
We have a long list of suspects – the coral host, the symbiotic algae Symbiodinium, or the other coral-hosted bacteria. The evidence thus far has pointed to Symbiodinium as the perpetrator. And in fact, coral bleaching is attributed to overproduction of superoxide by Symbiodinium in response to light and temperature stress. But, has Symbiodinium received a fair trial? To date, the evidence against Symbiodinium has been indirect. There are no actual measurements of superoxide production from corals or the algae during the bleaching process and the source of and triggers for superoxide formation are not actually clear.
We hope to unravel this mystery – at least in part – by conducting the first field-based (in situ) superoxide measurements from bleaching and non-bleaching corals during the natural bleaching event occurring in Kaneohe Bay, Oahu. But collecting this evidence is tricky. Superoxide only has a lifetime of a few minutes. It’s hard to catch. There are no instruments that we can put in the water to measure it. But, we may have a way – by setting up a boat-based laboratory with an optimized detector system. By doing so, we hope to obtain clues as to whom is making superoxide, how this varies with coral species, and how superoxide links to coral bleaching. Is Symbiodinium truly to blame? The jury’s still out…