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.

Ask the Scientists

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.