Heritability of Coral Calcification Rates and Potential for Adaptation to Ocean Acidification

Date
2017-12
Authors
Delano, Mia
Contributor
Advisor
Toonen, Robert
Department
Global Environmental Science
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
University of Hawaii at Manoa
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
The increasing concentration of atmospheric carbon dioxide due to human activities is contributing to ocean acidification, which leads to a reduction in coral growth rates, but the mechanism by which this reduction occurs is unknown. Heritable variation underlies the potential for evolution over time, but the degree of variation in pH tolerances among corals, as well as the heritability of any such variation, was previously unknown. In this project, I calculated the heritability of calcification among eight of the dominant Hawaiian coral species under both ambient and low pH conditions predicted for the end of the century. Coral colonies were sampled across natural gradients in seawater chemistry from a total of six different locations around Oʻahu, Hawaiʻi. Coral calcification response was assessed per colony by comparing growth in grams per mg per day between replicate samples in low and ambient pH water. Heritability was assessed using an R package to calculate the amount of variation in calcification rates that is due to genetics and may be passed on to offspring. The results show that calcification rates are highly heritable across all eight species, and all eight may experience selective pressure for calcification rate under acidification. M. patula, P. meandrina, and P. evermanni in particular show statistically significant variation in pH tolerance among colonies, making these especially good candidates for future studies on adaptation to ocean acidification. Further studies combining additional variables such as sea surface temperature and nutrient availability may lead to the creation of a holistic predictive model of Hawaiian reef composition in the future.
Description
Keywords
Citation
Extent
34 pages
Format
Geographic Location
Time Period
Related To
Table of Contents
Rights
All UHM Honors Projects are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.