Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • BCO-DMO Processing Description
• Data Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

Reciprocal transplant experiment:
In February 2022, 32 colonies (subclone/ramet) of the Caribbean thin finger coral, Porites divaricata (Taxonomy ID: 262287) were identified. 3 to 9 branch fragments were collected from every subclone (colony/ramet). 1 to 3 fragments from each ramet were moved to three designated sites: M1 (mangrove site 1), M2 (mangrove site 2), and R (reef site). 7 to 9 adjacent ropes were deployed at each site (seven ropes at M1 and R, and nine ropes at M2). Following a six-month period (February 2022 - July 2022), two traits were measured for each fragment: length change and red channel intensity, which serves as an inverse indicator of chlorophyll pigment density (Winters, Holzman, Blekhman, Beer, & Loya, 2009).

Trait Measurements:
To measure fragment growth, all fragments were photographed against a scale before and after transplantation, and their lengths were measured from base to apex using ImageJ software. The change in fragment length was determined by dividing the difference between the final and initial lengths by the initial length of the fragment. To measure red channel intensity, all fragments were collected at the end of the experiment and photographed against a laminated DKK color standard (DGK Color Tools) featuring an eleven-step gray scale with true white. Employing the methodology outlined by Winters et al. (2009), these photographs were used to estimate the chlorophyll density of each fragment. Initially, all images were standardized using the gray scale and the MATLAB macro CalibrateImageA. Subsequently, the MATLAB macro AnalyzeIntensity was employed to compute the mean red channel intensity for 20 swatches measuring 25 × 25 pixels for each fragment. Higher values of red channel intensity indicate lower levels of algal photosynthetic pigments (and hence, lower chlorophyll density) (Winters et al., 2009). The MATLAB scripts CalibrateImageA and AnalyzeIntensity are provided in the supplementary files in Winters et al., 2009.

See 'Related Datasets' for the environmental data from the coral transplant sites.

- Imported original files "GPSCoords_Data.xlsx" (site locations) and "TraitVariation_Data.xlsx" (trait variation data) into the BCO-DMO system.
- Added Latitude and Longitude columns from the site locations list to the trait dataset by matching on Subclone_ID number.
- Moved the comment "could not get value from photo" which was in the R_fin column to a Comment column
- Saved the final file as "927890_v1_coral_trait_variation.csv".

NSF Award Abstract:
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

In this era of rapid environmental change and degradation, the survival of marine organisms will depend largely upon their ability to tolerate increasing environmental stress. However, the processes that drive resilience (e.g., the relative contribution of genetic versus environmental factors) remain largely a mystery. Corals are a major focus of current studies on organismal resilience because they are undergoing a worldwide decline, and they are so important for both the health of the oceans and the welfare of coastal communities. Corals often occupy and build habitats through asexual reproduction (production of clones), and it is widely assumed that such asexual populations may lack sufficient genetic diversity to respond to diverse environmental stressors. However, few previous studies have quantified the effects of asexual reproduction on the ability of corals to respond to environmental change. This research explores the different mechanisms that contribute to differences in coral stress response among two predominately clonal populations of the Caribbean thin finger coral (Porites divaricata) dwelling in distinct habitat types (mangroves vs. reef). This research will illuminate the drivers of organismal resilience, potentially impacting ongoing coral conservation and restoration efforts. It will also broaden the participation of underrepresented groups by encouraging active participation by local community members, students and scientists at the University of Belize, as well as providing unique training opportunities for next-generation scientists at the interface of field marine ecology and genomics. Importantly, these results will be communicated to a wide audience through diverse venues, including technical reports and management recommendations provided for government agencies and non-profit Belizean conservation organizations, popular articles and curricular materials for the community at large, and peer-reviewed manuscripts and presentations targeted to the scientific community.

Among conservation biologists and ecologists, there is an urgent effort underway to understand the causes of diversity in traits impacting organismal survival and reproduction. If we are to understand how natural populations will respond to environmental change, it is critical to understand how genetic, epigenetic, and environmental factors impact resilience. Such studies have advanced significantly in many plant species, but they are only just beginning to be applied to animals like corals. As in many plants, the model species used here - Caribbean thin finger coral (Porites divaricata) - reproduces primarily asexually, allowing us to compare the performance of clones in different environments and isolate the effects of genotype, epigenetics (namely DNA methylation), environment, and somatic mutations on variation in stress-related coral traits. Specially, combining fully-crossed reciprocally transplanted coral ramets across mangrove and reef sites with genomic and methylation sequencing data, this research will evaluate 1) the role of intra-genet variation accumulated during asexual reproduction in facilitating adaptation in the mangrove population, relative to roles of between-genet variation and phenotypic plasticity, 2) assess the role of new DNA methylation states, and 3) measure the rate of accumulation of new DNA methylation marks and base-changes during asexual reproduction. Results from this research effort will advance our understanding of the role of mechanisms like DNA methylation and somatic mutations in driving phenotypic variation in critical stress-response traits and how these mutations accumulate over time, provide insight into how such mechanisms are generated and inherited across asexual generations, build upon the sparse understanding of the role of novel habitat types, i.e. mangroves, in coral ecology and evolution; and generate novel molecular resources including the first reference genome assembly for the non-model coral, P. divaricata.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.