About This Project

Corals are under threat of extinction due to the long-term effects of climate change. Currently, the effects of these phenomena on coral growth is based primarily on short-term laboratory experiments, much shorter than the decades over which climate change occurs. To address this, I will obtain information from annually-banded skeletons of massive, long-lived corals to produce a well-replicated, long-term reconstruction of growth rates across Hawaii.

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What is the context of this research?

Even with substantial reductions in greenhouse gas emissions, corals worldwide are expected to experience mass bleaching events annually by 2100. Current knowledge of the effects of climate change on coral growth is based primarily on acute responses in short-term laboratory experiments. Although a year-long acidification experiment on coral growth was recently achieved, this timeframe still pales in comparison to the decades-to centuries timescale of ocean warming and acidification, which raises the question of whether laboratory experiments can realistically simulate both the chronic effects of—and any potential acclimation to—the long-term exposure happening in the ocean.

What is the significance of this project?

Skeletal cores from long-lived Porites colonies collected in the field provide the unique perspective of changes in coral growth over decades to centuries. This information cannot be acquired in short-term lab-based experiments. While climate change trends are increasing at alarming rates, these changes in oceanic conditions have occurred over the past century, and the only way to fully understand the effects is through core analysis. Both acute and chronic changes in Porites growth rates are highlighted through these techniques. My research will fill the knowledge gap of how coral responses in the field, over decadal or longer timescales. Ultimately, this information will guide more accurate predictions of future coral reef states.

What are the goals of the project?

The objective of my study is to produce a well-replicated, long-term reconstruction of coral growth rates across the tropics using state-of-the-art measurement and statistical tools. I hope to collect at least 15 samples from locations around Oahu. Specifically, I will answer the questions of whether (1) coral growth rates have declined since 1900, (2) there are regional differences in coral growth trends, and (3) there is evidence of acclimation to climate change. A series of statistical models will be developed to determine if and to what extent growth rates have changed. Reductions in growth rates followed by a return to normal growth rates would be indicative of acclimation to changing conditions.