By Julia Robins, Staff Writer
The Chesapeake Bay Foundation (CBF) has planted millions of oysters in the Lafayette and Piankatank Rivers. Until now, they’ve relied on a model to help choose places in the Bay for new restoration sites. But Tommy Leggett, manager of the CBF Virginia Oyster Restoration Center, says, “I didn’t want to put total confidence in that model.”
The model, developed by Virginia Institute of Marine Science (VIMS), predicts where oyster larvae will settle based on how water flows in rivers. It suggests that larvae will settle in the same river system as the planted adults. If planted oysters are producing a new generation of oysters that stays put, that would spell success for oyster restoration in that river.
Leggett teamed up with Brendan Turley, a VIMS graduate student, to confirm the model using genetic markers. Genetic markers are specific locations in a DNA sequence that are unique to species, populations, or individuals. CBF planted oysters in the Lafayette River that had unique genetic markers. By testing baby oysters for these markers, Turley can see whether new generations of oysters in the Lafayette River have parents that were part of the new planting.
In the long term, genetic testing could allow rapid assessment of restoration efforts and confirmation of the model’s predictions. But getting the genetic testing machine up and running requires scientists to develop and perfect it. With funding from Virginia Sea Grant, Turley fine-tuned the testing method, began collecting baby oysters along the river, and compared their genetic profiles to the profiles of the planted oysters. So far, he has found quite a bit of genetic similarity, which could be a sign that restoration efforts are taking hold.
“It is the hope that my analysis of the data will give some credence to the possibility that the CBF plantings are contributing to the reproductive success of the oysters in the region,” says Turley.
He stresses, however, that more research must be done to definitively understand how these efforts effect restoration in the region.
“This is a great feasibility study,” says Jan McDowell, a VIMS scientist and one of Turley’s academic advisors. “We could actually look for signals of the positive benefits of restoration efforts.”
Beyond testing for the effectiveness of CBF’s restoration, Turley’s work has provided a new method for genetic tracking that could make this genetic testing much easier in the future.
“We’ve taken this new machine and come up with a really good, pretty robust protocol that can be used down the line, for years and years,” says Turley.
“This has been another great collaboration with VIMS,” says Leggett. “There’s no book written on how to restore oysters, so I think the more things we try the more we learn.”
