Last week we touched on the reasons a Florida archaeologist might be interested in shellfish ecology, and all of the potential information and/or data that can be derived from the study of these invertebrates. Today, we're going to look at some of the "usual suspects" found both on Northeast Florida beaches and inside prehistoric shell middens.
This large gastropod (single-valved and spiral-shaped shell) ranges from Massachusetts to the Cape Canaveral region, and is found throughout NE Florida in estuaries and bays in 1 m of water, and even in some open-coast habitats up to 50 m. Knobbed whelks are carnivores, feeding on bivalves such as oysters and clams.
Knobbed whelks were not only used as a subsistence resource by Timucuan Indians, but also as a utilitarian tool. The entire shell could easily be hafted to a wooden pole, creating a shell axe or hammer. Axes were necessary to fell trees for village structures, hallow trees for canoes, and any other cutting needs.
The venerable oyster has certainly solidified its place on the dinner tables of both Native and modern populations alike. Perhaps no other shellfish is as recognizable. Oysters are quite hardy, living in a range of salinities, from estuaries, bays, and brackish sounds, to full seawater habitats. They are filter feeders, attaching themselves to hard structures on the seafloor. Oyster beds create their own mini-ecosystem or reef, supporting numerous other aquatic organisms.
Oysters are the most common shell in Florida middens, serving a multitude of purposes. These critters were food for Natives, served as construction materials for mounds and walkways (many offshore islands along Florida's coasts are made almost ENTIRELY of oyster midden), and even as expedient tools such as scrapers. Carl Halbirt, city archaeologist of St. Augustine, has excavated numerous prehistoric middens with these sorts of tools.
Coquina was an extremely valuable resource, both prehistorically as food for Florida Natives, but also as building material for historic settlers in Northeast Florida. Coquina was used to construct sugar mills, iconic structures like the Castillo de San Marcos and Fort Matanzas, and hundreds of fences, walls, and smaller buildings. Interestingly, today, coquina is a proxy of how healthy a particular beach habitat is.
The Atlantic giant cockle--also called the great heart cockle--is the largest cockle species found in northeast Florida and thus was an important shellfish subsistence resource for Timucua Natives and other prehistoric groups. It's easily identified by its bright orange and white check-stamped colors and its parallel ridges.
The Shark's eye (or "moon snail") is also common to northeast Florida beaches and prehistoric shell middens, though the prehistoric ones are often much bigger (could they have been overfished in the past?).
Stay tuned for more on northeast Florida shellfish archaeology and environmental posts!
Text and Images, Ryan Harke, FPAN Staff. Credit to Jaxshells.org for the knobbed whelk photograph, iloveshelling.com for the coquina, shark's eye, and giant cockle photos.