Shell Preparation - Deep Cleaning!

Aloha everyone! We are hard at work cleaning our shells to prepare them for shipping and isotope analysis. Time for another shell update!

We are planning on sending oru shells to the UC Davis Stable Isotope Facility for stable isotope (13C and 18O) analysis, and Lawrence Livermore National Laboratory for radiocarbon (14C) analysis. Each isotope facility needs shells to be prepared for analysis in slightly different ways, but they both have one thing in common: shells must be completely clean! Our shells have been sitting in the dirt at Ka'ena Point State Park for thousands of years, accumulating dirt, so we have a challenge ahead of us!

In my last update, I told you all about how we were cleaning the outside of our shells. However, the structure of our shells and the amount of time they've been sitting in the dirt means that our shells have accumulated dirt inside their structures as well! The outside of our shells are clean; now we need to clean the inside as well.

 

An Amastra sp. shell that appears clean on the outside.

After two days (48 hours) of soaking in a hot water bath with periodic sonication, most of our shells appeared outwardly clean. However, some shells still had dirt caked on the outside, and we were able to clean this dirt off with scraping tools. Now came the hard part: getting to the dirt on the inside!

As part of UC Davis's preparation protocols, shells will need to be pulverized to a fine powder prior to shipping, giving us the freedom to open our shells up and see how much dirt was inside without fear of ruining the sample.

 

Dirt inside what appeared to be a clean Amastra sp. shell.

Overall, our shells were not too dirty! Our method of soaking them for 48 hours loosened most of the soil, allowing it to fall out naturally. All of our shells had some dirt clinging to the shell, which we are able to carefully remove with a combination of scraping tools and water.

 

An Endodonta sp. shell, aperture down, after cleaning the outside and prior to cleaning the inside.

 

An Endodonta sp. shell, aperture up, after opening it and in the process of cleaning the inside.

Each shell takes between half an hour to an hour to clean. We are being very careful with this process, making sure to remove all dirt while keeping shells as intact as possible for now. To make sure we get all the dirt, we are cleaning our shells under a microscope, which allows us to see our shells more clearly than we could with the naked eye.

 

A Leptachatina sp. shell in the process of being cleaned.

After thoroughly cleaning all shells, the next step will be to dry them in an incubator to remove any residual moisture. Then we have some facility-specific preparation to do: shells will be broken in half, so that each facility receives half of each shell. UC Davis requires that the shells that they receive be pulverized into a fine powder, while Lawrence Livermore prefers intact shell fragments. We have more work ahead of us!

Mahalo for all of your support! We are excited to share our progress with you all.