HCNSO Student Theses and Dissertations
Optimization of Light Irradiance During the Early Life of Sexually-Produced Porites astreoides and Agaricia agaricites Recruits
M.S. Marine Biology
Joanna Figueiredo, Ph. D
Brian Walker, Ph. D
Bernhard Riegl, Ph. D
Charlie Gregory, DVM
Current solutions of coral restoration rely mainly on fragmentation. Though a reliable technique, this asexual form of reproduction does not benefit the genetic diversity of the coral reef. With many global and local stressors threatening corals’ existence, the resiliency of corals to future ocean conditions depends highly on sexual reproduction to produce new genotypes. New technology allows coral spawning/larval release, larval settlement and rearing to be carried out in an aquarium system. Many of the techniques necessary to maintain coral recruits are well-established, however the effects of light intensity remain to be studied for these early life stages. Newly settled corals have been found on vertical surfaces and the undersides of ledges and crevices, suggesting full solar irradiance is detrimental to their health. Newly settled Porites astreoides and Agaricia agaricites recruits were placed under varying irradiance levels to test their survivorship, growth and pigmentation. In the first four weeks post-settlement, growth was significantly different between recruits under a PAR of 10 µmol quanta m-2 s-1 and 240 µmol quanta m-2 s-1. In a separate experiment, growth curves were significantly different between six different irradiance increase regimens in the first 14 weeks post-settlement. This study shows, for the first time, a definitive preference by newly settled coral recruits to lower intensity irradiance, devoid of ultraviolet radiation, in the first four weeks post-settlement, and that Porites astreoides recruits can acclimatize to higher intensities at a rate of ~ 11 µmol quanta m-2 s-1 per week for up to 15 weeks.
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Nicholas J. McMahon. 2018. Optimization of Light Irradiance During the Early Life of Sexually-Produced Porites astreoides and Agaricia agaricites Recruits. Master's thesis. Nova Southeastern University. Retrieved from NSUWorks, . (493)
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