Analyzing factors for out-planting strategies of Acropora cervicornis genotypes residing in nurseries

Open Access
Author:
Weinheimer, Alaina Rose
Area of Honors:
Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Iliana Brigitta Baums, Thesis Supervisor
  • Michael Axtell, Honors Advisor
Keywords:
  • coral
  • ocean acidification
  • compatibility
  • molecular ecology
  • coral restoration
Abstract:
Coral reefs are ecologically and economically critical ecosystems. Over the past few decades, coral cover in the Caribbean has declined over 80%. Coral nurseries, which house hundreds of coral fragments, have been created in an effort to restore these reefs. Once the coral fragments reach a certain size, they are planted in the wild. Many nurseries contain fragments of Acropora cervicornis, or staghorn coral. A. cervicornis is a relatively rapidly growing species that once dominated many reefs in the Caribbean. Deciding which staghorn coral fragments to plant in the wild requires considering numerous factors. This study looked at which staghorn coral are most resistant to ocean acidification. As the ocean becomes more acidic, the ability of organisms, such as coral, to calcify has been suspected to reduce. In this study, we examined which genotypes of staghorn coral are less impacted by ocean acidification by analyzing coral growth rates, physiology, and microbial communities. Genotypic differences were difficult to resolve due to a small sample size; however, significant differences were detected between the coral fragments exposed to the different pH treatments. Additionally, this study examined staghorn coral fragments for sexual reproductive compatibility. Maintaining genetic diversity for sessile organisms, such as coral, heavily relies on sexual reproduction. As the densities of staghorn coral populations decrease, the number of mates, successful fertilization occurrences, and dispersal abilities of staghorn coral has decreased, making this species more vulnerable to extinction due to environmental change. This study looked at the compatibility between staghorn coral individuals growing in a nursery. The individuals that mated most frequently together would be planted with each other. Because coral lack a known compatibility feature, compatibility was determined by genotypes of larvae from crosses containing known parents. The data generated from this study had the potential to be used by coral reef nursery managers when deciding which A. cervicornis individuals to plant in the wild.