About This Project

We hypothesize that, even on extremely small-scales, there are genotypes in Hawaiian corals that are associated with areas of high temperature and/or temperature variation. We will utilize genomic methods (ddRAD) to characterize coral genotypes and make comparisons with existing environmental data.

If local adaptation exists on this scale, we can promote exchange of genes between populations with thermotolerant traits and those without to increase resilience to bleaching events.

Ask the Scientists

What is the context of this research?

Studies of coral bleaching often do not consider the effect of coral population dynamics and tend to focus heavily on symbiotic zooxanthellae communities (only recently have studies begun utilizing population genomic methods (eg. 1, 2, 3), e.g. ddRADseq). While these microbial communities are essential to the long-term survival of corals, studying them without considering the genetic structure of the coral host leads to an incomplete understanding of the drivers of bleaching events. Thus, the first step to better understanding coral-symbiont-climate dynamics is to see if and how coral populations structure genetically on a small-scale. This study aims to do so using two major reef-building corals, Montipora capitata and Porites compressa in Kaneohe Bay of Oahu, Hawaii.

What is the significance of this project?

Understanding population genetic structuring on a fine-scale, like in the Kaneohe Bay system, can increase our abilities in conservation and restoration. In order for conservation efforts such as selective breeding and restoration to be successful, breeding individuals must be taken from within a regional pool. Breeding between regions can result in offspring that are unfit in regards to other localized conditions (e.g. biotic interactions, light requirements, nutrient tolerance, etc.). Thus, it is crucial that this study uncover which oceanographic conditions, if any, drive genetic structure and local adaptation in corals on a small scale. Such information will provide a search criteria for locating thermally adapted populations elsewhere in the world via remote sensing.

What are the goals of the project?

This study has two goals: 1) to evaluate if certain genotypes are correlated with oceanographic conditions such as average temperature, temperature variation, and current velocity and 2) to evaluate if these patterns (if any) differ between the two taxa. We will sequence 96 coral DNA samples (using ddRAD reduced representation sequencing) split between 2 species, Montipora capitata and Porites compressa, equally sampled across Kaneohe Bay in Oahu. The resulting genetic data will be analyzed and compared with oceanographic data. If genetic patterns align with hotspots of mean temperature, temperature variation, or any combination of oceanographic conditions, there is support for the hypothesis that genetic patterns arise from these abiotic conditions, even on an incredibly fine scale.