Unfortunately, less than a week later, the shores of the island were once again surprised by extreme weather in the form of a strong winter storm carrying 20 foot waves and 35 knot winds. After inspecting the shape of our experimental sites, it is safe to say that the consequences of this event were comparable to those of last year’s hurricanes. Indeed, more than 75% of the coral fragments recovered died during this event, and most survivors lost their identification tags, leaving them useless for our experiments.
Under such a gloomy scenario, we had no other choice but to raise to the challenge of building our experiment all over again. However, we could not afford to have all corals at the mercy of another potential storm over the next year. Thus, after a general team meeting, it was decided that two experimental sites at two different reefs with different orientations will be set this time. However, the logistic implications of this idea were enormous: instead of 100 fragments we will be looking at 200 fragments in total, plus setting transects and nails for a new location at 2 different depths, and all in just 2 days.
Fortunately, the outcome of this trip exceeded all expectations. We were able to recover our experimental plots at the original reef site and created new ones in another one, rescuing 200 fragments from four different reefs around Culebra. Overall, we out-planted a total of 400 corals fragments, at two different depths and in two different sites. The success of this mission was possible thanks to an intensive coordination, diving and tagging operation featuring a team of 10 people including scientists, students and volunteers from FIU, UPR and SAM. We will continue to monitor these corals monthly for a year, obtaining results that will help us understand how corals acclimatize to stress and providing keys for their conservation and management in the future.
In the present trip, we rescued approximately 100 staghorn coral fragments from three different reefs in the Island of Culebra, stabilizing them at two different depths. The hurricane impact was evident based on the high fragmentation observed in most of the recovered corals. We assessed coral morphometric parameters to start the demographic description of their recovery, and measured photosynthetic efficiency of coral fragments as an indicator of their physiological state. Samples were also collected to assess coral and symbiont genotypes, bacterial diversity and epigenomic modifications.
We are already planning the next expedition for the end of March 2018, assessing the status of the coral fragments collected previously, as well as increasing the number of recovered fragments up to 200 before starting monthly surveys.