PNNL

Long-lived organisms, especially those that grow sequential tissues, provide a unique ability to examine diachronic records of environmental information over time – think of tree rings, or layers in a mollusk shell. This is particularly true for chelonians (turtles, tortoises, and sea turtles) who grow their shell scute keratin in layers throughout the course of their life.

In this presentation, Dr. Cyler Conrad will discuss the results of ongoing research funded by Los Alamos National Laboratory’s Laboratory Directed Research and Development program investigating the bioaccumulation, retention, and signatures of anthropogenic radionuclides (especially uranium) in a variety of chelonians from nuclear sites.

By analyzing turtles, tortoises, and sea turtles from former nuclear testing sites – the Republic of the Marshall Islands and the Nevada Test Site – and nuclear processing sites – the Savannah River Site and the Oak Ridge Reservation – we identify legacy uranium signatures in scute growth rings that are associated with 20^th century nuclear activities at each location. These results highlight the ability of using chelonian scutes as a passive, and proxy, record of anthropogenic radionuclide contamination in both past and present contexts. 

Watch the seminar here:

Learn more about this research:

• PNAS Nexus (read the research) paper, August 22, 2023: Anthropogenic uranium signatures in turtles, tortoises, and sea turtles from nuclear sites.
• National Public Radio’s Science Friday, September 15, 2023: What Radioactive Animals Teach Us About Nuclear Fallout
• Wired, August 30, 2023: Turtles Carry Signs of Humanity’s Nuclear History in Their Shells
• Australian Broadcasting Corporation, August 29, 2023: Scientists find turtles with nuclear contaminated shells in the Marshall Islands
• Smithsonian, August 29, 2023: Turtle Shells Keep a Record of Humans’ Nuclear History
• Scientific American, August 22, 2023: Turtle Shells Record Nuclear History
• New Scientist, August 22, 2023: Turtles Keep a Record of Nuclear Activity in their Shells