There is a tradition among foodies that wild oysters must only be eaten in months with the letter “r” — September to April — to avoid eating watery shellfish or picking up a nasty case In recent years, new research indicates that people have been practicing this Ancient inhabitants of St. Catherines Island harvested oysters only when the weather was not summer-like, as revealed by a large shell ring found off the coast of Georgia. Scientists must know when islanders were collecting oysters in order to do their research. Using parasitic snails as a measure. These type of snails, often referred to as impressed odostomes, inject a stylus into a shell to eat the soft interior, then latch on to the shell to eat it. The 12 month life cycle of the snail can provide researchers Nicole Cannarozzi and Michal Kowalewski with an accurate estimate when the oyster they were studying died, allowing them to use the snail as an historic clock to track when people collected and consumed oysters.

There has been much debate over the significance of these fragmentary rings for a long time, said Amelia Cannarozzi, lead author of the study and manager of the Florida Museum environmental archaeology collection. What did they look like? Were they just Is this a temporary communal feasting site? Could it be a combination of the two? Cannarozzi and Kowalewski examined oysters and snails from an old shell ring found on St. Catherines Island and compared them to live animals. Understanding how the shell rings had changed over time sheds new light on their purpose.” The researchers found that island inhabitants harvested oysters primarily at the end of winter, early spring, and the summer months, which also suggested the presence of people on the island was decreasing. In the Southeast, oysters spawn from May to October, and avoiding oyster harvest throughout the summer period may help replenish their numbers, Cannarozzi said. There is no need to harvest oysters during the summer months to help replenish their numbers, Cannarozzi said. As an alternative to stable isotope analysis and an examination of shell growth rings, this approach can be complementary to other archaeological methods. Several key requirements for the life cycle of ‘timepiece’ organisms must be met for the method to be useful for other marine invertebrate studies, Kowalewski said. It may also be possible to use species with a lifespan of one year or less, consistent growth patterns, and predictable reproduction patterns, as clocks. We might be able to reconstruct population dynamics or the natural history of extinct species that use this type of approach. During their research project, they combined paleontology, the study of fossils and other biological remains, with archaeology, an emphasis on Among the strands of Cannarozzi’s specialization — environmental archaeology — are the close relationships between humans and nature. People have had an impact on the distributions, life cycles, and numbers of organisms throughout history, Cannarozzi noted. “Understanding how people in the past interacted with and influenced their environment will help us in The study of how oysters have lived in their environment over time can provide valuable information about their ecology, how other organisms interact with them, the health of oyster populations, and the health of coastal ecosystems. Particularly considering the fact that oyster populations are declining worldwide, she said.