Just prior to the twelve month sampling cruise in September 2016, a bleaching event began at the Flower Garden Banks, where the transplants and shallow controls were observed to be severely bleached (more about that cruise here). While transplants appeared to be more visually susceptible to bleaching stress than their shallow counterparts, transcriptomic patterns and zooxanthellae/chlorophyll concentrations suggested similar stress responses in both depth treatments. This most recent cruise was the first time the experimental colonies had been revisited, and the Voss Lab was pleasantly surprised to see that none of the transplants or shallow controls appeared to have died due to the bleaching event. Several of the transplants had been dislodged from the bottom (possibly due to Hurricane Harvey in 2017), resulting in toppling and slow colony mortality. Despite this disappointing fate for some transplants, the data from this experiment will allow for better understanding of the molecular mechanisms behind rapid adaptation and/or acclimation to new environments.
In addition to the transplant experiment objectives, the team sampled additional benthic taxa including corals (Orbicella faveolata, Stephanocoenia intersepta) and a sponge (Xestospongia muta) for enhanced population genetics research in the northwest Gulf of Mexico (NWGOM) as part of a new NOAA-funded research collaboration with Dr. Santiago Herrera at Lehigh University. These species will aid in ongoing assessments of population structure of mesophotic environments across the NWGOM and wider Tropical Western Atlantic, and will provide valuable genetic data to the current proposal to expand the FGBNMS boundaries to include additional mesophotic banks in the NWGOM. While conducting sampling dives both within the sanctuary and outside the existing FGBNMS boundaries at Bright and McGrail Banks, the divers were fortunate to observe several manta rays, friendly groupers, and X. muta spawning.
The team would like to sincerely thank the new crew of the R/V Manta for a productive and safe week offshore, and FGBNMS staff for providing research permits for both projects. This research is supported by NOAA's Cooperative Institute for Ocean Exploration, Research, and Technology (CIOERT) headquartered at FAU Harbor Branch.
To see more photos from the research cruise, see our Flickr album here. To see a few short videos from the cruise, including scooter rides up the bank margins at West and East FGB, see our Youtube playlist here.