Why did a prehistoric community of snails in Hawaii go extinct?

Raised of $1,000 Goal
Ended on 9/16/22
Campaign Ended
  • $111
  • 12%
  • Finished
    on 9/16/22

About This Project

After the last ice age, temperatures in the Northern hemisphere rose and precipitation levels were dramatically altered. We are beginning to understand how these changes impacted many areas, but what about Hawaii? We have dated shells from extinct, endemic Hawaiian snails to this period of global change, and we will use isotopes from these shells to examine how Hawaii's environment changed. We hypothesize that rising temperature and lowered precipitation led to the extinction of these snails.

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What is the context of this research?

After the Last Glacial Period (better known as the Ice Age), the Northern hemisphere experienced climatic change. We understand how this period of change affected many areas, but we know very little about how Hawaii's environment adjusted to this change. This study, which will make up my graduate thesis work, will help us understand how an area on Hawaii's modern-day dry, leeward coast was impacted.

Hawaiian land snails (for the most part) are only found in wet and cool environments. However, we have found ancient shells in what is now a very hot and dry desert. We have dated several of these shells to the Last Glacial Period. Because these snails lived in this (now) dry area, we expect that the environment must have been very different in the past, and underwent environmental change.

What is the significance of this project?

Anthropogenic (human-caused) climate change is a serious issue in the modern day, and one that greatly concerns me as a researcher. Scientists understand that the Earth has experienced periods of gradual climate and environmental change in the past, and we can use the information we learn from these periods of past environmental change to help us better conserve our natural resources today.

Each individual shell will give us information about what the climate was like on Oahu's presently dry, leeward coast over 40,000 years ago. By looking at data from several shells, we can examine how the climate changed over time. Understanding this prehistoric change in climate can help us better preserve our natural resources today, as present-day climate heats up.

What are the goals of the project?

We will use stable isotope (d13C and d18O) and radiocarbon isotope (14C) analysis to reconstruct the prehistoric environment that each snail lived in. 13C isotopes tell us what type of vegetation the snail was living and feeding off of. 18O isotopes tell us roughly how much precipitation the area was receiving (via rain or humidity), and what the ambient temperature was like in the area. Combining each shell's data, we can look at how the environment changed through time, and whether it became unsuitable (too hot and dry) for these snails, contributing to their extinction.

We expect that this information will be useful for resource managers. Knowing how the prehistoric changing climate impacted the environment will help us make decisions today regarding environment preservation.


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Radiocarbon (14C) dating is a reliable way to get data on the age of the subject. In the case of our project, radiocarbon dating will tell us how long ago our snails lived.

The stable isotope portion of our project has been successfully funded via small (<$1000) grants from the Society for Integrative and Comparative Biology, and the Association of Applied Paleontological Sciences! We have also received grants from the Conchologists of America and the Paleontological Society to fund radiocarbon analysis on some of our shells.

However, we need a bit more funding to conduct radiocarbon analysis on all of our snail shell samples.

This data will allow us to place the environmental information we learn about through stable isotope analysis to a specific point in time, and by analyzing multiple shells, examine how the environmental conditions changed over the course of time.

Endorsed by

This project has been many years in the making. In fact I have been thinking about these intriguing extinct species and the conditions they lived under for more than two decades, since I first discovered that there were land snail shells in this inhospitable arid area. I find it so intriguing that this community of snail species that require relatively wet conditions and complex forest with closed canopy are found in this open shrub and grassland, strongly suggesting that conditions here at Kaena Point are vastly different than they once were.
I am really excited to see Sam's project results. Sam is a very dedicated student whose knowledge on Hawaiian snails blows me away every time I hear about it. This project is very useful in understanding past effects of climate change here on Oahu.
Sam Arsenault is an incredibly smart, dedicated, hardworking scientist who's exceedingly capable of accomplishing her goals, given sufficient funding. Her research will shed light on historical climate patterns on Oahu that will have implications for future climate change.

Project Timeline

Shells have already been gathered from the study site.

In late June, we expect to send our samples to outside facilities to conduct stable isotope and radiocarbon isotope data analysis.

We will analyze all data as soon as we receive the results back from the outside facilities, and we expect to complete this project by December 2022.

We expect to publish this data in a peer-reviewed scientific journal shortly after completing the data analysis.

May 28, 2021

Gather all shells from Ka'ena Point State Park

May 09, 2022

Project Launched

Jun 07, 2022

Begin preparing shells for isotope analysis

Jun 12, 2022

Project Launched

Jun 13, 2022

Finish cleaning shells for isotope analysis

Meet the Team

Samantha Arsenault
Samantha Arsenault
Master's of Science in Marine Science Candidate


Hawai'i Pacific University
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Brenden Holland
Brenden Holland
Associate Professor


Hawaii Pacific University
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Samantha Arsenault

I am a second-year Master's of Science in Marine Science candidate at Hawai'i Pacific University. I have always loved spending time in nature, and since a young age, I have wanted to learn everything I could about the natural world. In 2017, I graduated from the University of Southern California with a degree in Biological Sciences, and shortly after graduating completed a number of conservation-based internships.

Feeling a calling to do more to support the conservation of our natural resources, I moved to Hawai'i in 2020 to begin my graduate studies at Hawai'i Pacific University. I ultimately plan to pursue a career in environmental conservation, and I strongly feel that research, such as this project that will make up my master's thesis work, is one of the best ways to understand how we can conserve our most valuable resources in the face of modern-day global climate change.

Brenden Holland

I think it was a Sylvia Earle said, "We have become frighteningly effective at altering nature."

I'm a broadly trained ecologist with interests in what we can do to maintain natural levels of terrestrial and marine biodiversity. The majority of scientific projects that I've been involved with in recent years have underpinnings in Conservation Biology, and have focused on quantifying and understanding ecological challenges, how to solve them, and ultimately how best to protect and preserve native species and their habitats.

I have an undergraduate degree in Biological Science from UC San Diego, and MS and PhD degrees in Oceanography from Texas A&M University. I grew up exploring the tide pools, kelp beds, creeks and redwood forests of the west coast, and somehow never lost my childhood curiosity about the natural world. I continue to this day to encourage my students to ask questions, and keep exploring. Along the way, I strive to instill in them the notion that, "By taking care of nature, we take care of ourselves".

Additional Information

This study will be the first of its kind in the Hawaiian Islands. The use of snail shells to reconstruct climate is well-established. However, it has not yet been done in Hawaii.

A Special Use Permit has been obtained from the Department of Land and Natural Resources (DLNR) for the purposes of collecting snail shells from the study site, and all shells needed for this project have already been collected.

Our project has gathered some local attention, and we have been featured in several news articles! We have been featured in Hawai'i Pacific University's school newsletter, the 'Ohana, as well as a Spectrum News article and a spotlight on Hawaii News Now.

Project Backers

  • 8Backers
  • 12%Funded
  • $111Total Donations
  • $13.88Average Donation
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