Only Eat Oysters in Months with an ‘R’? Rule of Thumb Is at Least 4,000 Years Old

Florida Museum Photo By Kristen Grace    

Using the impressed odostome is a cost-effective way to supplement other methods of dating shell specimens from archaeological sites. Cannarozzi said it’s important to study how oysters have lived in their environments over time to understand the health of the region’s coastal ecosystems.

“It’s important to look at how oysters have lived in their environment over time, especially because they are on the decline worldwide,” she said. “This type of data can give us good information about their ecology, how other organisms interact with them, the health of oyster populations and, on a grander scale, the health of coastal ecosystems.”

Cannarozzi said using impressed odostomes to gauge what time of year oysters were harvested offers an independent way to assess ancient patterns of oyster gathering. This approach can complement other archaeological methods, including stable isotope analysis and examining shell growth rings.

Kowalewski said the method could be applied to other marine invertebrate studies if the “timepiece” organism’s life cycle meets several key requirements.

In addition to being easy to find, the impressed odostome has a consistent annual life cycle – one of the key characteristics that makes it a good candidate for supplementing modern specimen dating techniques.

 

“If you have species with a lifespan of one year or less, consistent growth patterns and predictable spawning behavior, you could potentially use them as clocks as well,” he said. “We might be able to use this type of strategy to reconstruct population dynamics or the natural history of various species, especially those that are extinct.”

Cannarozzi and Kowalewski emphasized the importance of interdisciplinary collaboration in addressing longstanding research questions in new ways. Their project combined paleontology, the study of fossils and other biological remains, with archaeology, which emphasizes human history. Cannarozzi’s specialization – environmental archaeology – also explores the close connections between humans and their natural resources.

“People have affected the distributions, life cycles and numbers of organisms over time,” Cannarozzi said. “Understanding how people in the past interacted with and influenced their environment can inform our conservation efforts today.”

The researchers published their findings in PLOS ONE.

Contacts and sources:
by Halle Marchese, Mary-Lou Watkinson and Natalie van Hoose
Nicole Cannarozzi, Michal Kowalewski
Florida Museum of Natural History

Citation: Seasonal oyster harvesting recorded in a Late Archaic period shell ring. Nicole R. Cannarozzi, Michal Kowalewski. PLOS ONE, 2019; 14 (11): e0224666 DOI: 10.1371/journal.pone.0224666