Why paleontologists turn to the oyster business in Florida


But oyster harvesting was not easy. At low tide, oyster reefs are surrounded by sticky mud that sometimes reaches the thigh. The shells themselves are sharp and covered with infection-causing bacteria. This made heavy gloves and a strong balance essential when maneuvering around exposed reefs.

Fossilized gray oyster shells, rough and often mottled with clumps, don’t look like much, but collectively they preserve decades of important data. The researchers were particularly interested in how the size of oysters changes during the collapse of fisheries. According to Durham, the size of an oyster’s shell can tell you how fast an animal grows, how long it lives, and how it will respond to changes in water quality during its life, among other information.

Measuring the envelope volumes of previous generations and creating a timeline based on that data has also helped scientists combat the phenomenon of shifting baselines — what Dietl calls “generational amnesia.” Since environmental degradation occurs over time, it can alter the perception of natural conditions. For example, the size of oysters lapping above the waves today may seem normal, but once the project is complete, researchers may find that the animals are half the size of more robust ancestors.

After they are measured, the shells are deposited in the collection of the Paleontological Research Institute. About 40,000 shells harvested from oyster corals in Florida have already made their way to Ithaca, neatly arranged in drawers or lined with plastic and stored in buckets. Each shell holds an important data point that determines the future of oysters in Florida. All information is added to the database that will help environmental managers determine which reefs are the lowest – and which have the potential to be saved.

Dittel’s historic oyster body size project is just one of several in the burgeoning field of conservation palaeobiology, where fossil data inform modern conservation efforts. Karl Felsa, a University of Arizona geologist who has worked with Dittel on other projects, likens the effort to “running the dead.”

In his own work, Felisa uses clam fossils to plot the shape of the Colorado River delta’s decay. When the river was dammed in the 1930s, the amount of water reaching the delta wetlands slowed considerably. This left whole islands of dried clam shells for Felisa to study. More recently, his work has helped restore pockets of riverine habitat to a dry riverbed.

Florida’s environmental managers are already reaping the benefits of Dietel’s work. As they recreate the reef by laying out limestone or fossilized oyster shells to provide durable surfaces for clams to attach, Brooker’s team is also collecting samples from live oysters. Back in the lab, these oysters are measured, weighed and entered into a database, just like their fossilized relatives in Ithaca. The work, while early on, is promising. “We saw more adult oysters than the last time we were there, over a year ago,” Brocker says.

This is particularly encouraging given the dismal state of oysters globally. Some estimate that 85 percent of oyster reef habitat worldwide has been lost over the past two centuries. The eastern oyster found along the Florida Panhandle is a microcosm of this larger trend. once found from Texas to who, functionally extinct along large swaths of the New England coast. “It’s a hands-on deck moment in the oyster world,” says Durham.


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