Monday, July 04, 2011

Happy & Healthy Coral Transplants!

Anne and I spent a few days last week checking the finger coral (Porites compressa) transplants we deployed last September.  We were very excited to find that about 2/3 of the 80 transplants are still at least partially alive.  Many of them look very healthy and are the only coral in the area (photo to left).  We transplanted corals to 5 reefs in a line moving offshore from Rusty Bucket.  

These reefs were originally built by finger coral, but now have very little coral, lots of algae, and definitely no finger coral, so it’s really exciting that our restoration experiment seems to be working so far.  Our labmate Wendy planned and organized the experiment and hopefully will be coming back out here this summer briefly to finish it up.  I wrote a blog post last year (9/15/2010) on this experiment if you want more background. 

When we reached each site, Anne and I would scuba dive to 5-10 feet and find and clean as many of the metal tags as we could.  There were 4 groups of 10 shallow (5-7 ft) transplants and 4 groups of 10 deep (8-10 ft) transplants.  Anne measured the height and amount of live tissue of each transplant, while I photographed each with a ruler for scale. 

The Monument has prioritized restoring these reefs because they are very degraded (we’re not sure why – sewage output nearby for many years, etc.) and intact finger coral patch reefs host a diverse and unique group of organisms.  We went to one of these reefs a few days later and found very high coral cover, lots of bivalves including black-lipped pearl oysters, a lionfish, and seagrass, among many other organisms (photos above and to left).  This particular reef was hit very hard by the storms and/or tsunami this winter and changed its shape and depth quite a lot.  I had buoys and spat collectors attached to cement blocks, and they were moved all over.  Fortunately, we were able to find all of them eventually though!

We also just re-started a project of mine from two years ago to determine abundance (density) and size distribution of bivalves throughout Midway’s shallow marine environments.  I used GIS and remote sensing to divide the atoll into 4 habitats (sand, backreef, forereef, patch reef) and randomly select sites to do surveys.  When we surveyed about half the sites in 2009, we found a lot more bivalves on the forereef and patch reefs than backreefs and none on sand.  

We did 4 surveys of backreef yesterday and found only 1 bivalve.  However, we did see a flatfish, an octopus, and a giant porcupinefish.  A monk seal pup, K00 (photo to right), also found our boat fascinating and circled us for half an hour; he was very cute and I took lots of photos, but eventually we wanted him to go away so we could go in the water!

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