In his lab, Steve Ailstock has come up with a technique that may offer hope for a speedier comeback of the Bay’s submerged aquatic vegetation: growing grasses in glasses.
In rows of water-filled jars, Ailstock, an environmental scientist at Anne Arundel Community College in Maryland, has a small meadow of underwater grasses under production.
These grasses were slated to be transplanted in parts of the Magothy and South rivers to jump-start the growth of grass beds in areas that have long been barren, as part of a project that is being funded by the U.S. Fish & Wildlife Service’s Chesapeake Bay Program Office.
If successful, the process could help solve one of the most vexing problems of underwater grass restoration in the Bay — where to get plants without digging up existing beds.
“I’m not a huge fan of going into healthy SAV beds and digging them up and transplanting them,” Ailstock said. “If the plants look like they’re healthy in one location, leave them alone.”
Ailstock began using his technique in the 1980s when he was researching the effects of contaminants on underwater grasses. Back then, the goal was to get near-identical plants in the lab, some of which would be exposed to various levels of contaminants while others would be used in uncontaminated “control” environments.
What better way to get identical plant material than to clone it? Cloning may be controversial for sheep and humans, but it’s a natural process for many plants and is widely practiced in nursery plant production. “They can do it cheaper and make more money,” Ailstock explained.
Ailstock — with the assistance of his students — have adopted those techniques for five species of Bay grasses.
The original source of the plants still must come from the wild. But instead of digging up a single plant and transplanting it someplace else, Ailstock and his students cut the reproductive shoots from the plants into small pieces which are placed into individual test tubes. One plant, in effect, becomes many. “With this technique, I can sit down and turn out plant after plant,” Ailstock said.
After they grow large enough, they are transferred to larger jars. There, by maintaining water conditions conducive for growth and maintaining a flood of light on the plants, they grow far more rapidly than in the wild. “The expectation we have in culture is to get a fourfold increase in four to six weeks,” Ailstock said.
With future work, he said it may be possible to manipulate water conditions to promote even more rapid growth, perhaps by adding carbon dioxide, he said. Further, he noted, because they are produced in the lab, plants can be grown year round, rather than just part of the year in the wild.
The process is not without some questions. Because the technique essentially clones the same plant over and over, the process raises some concerns that the new grasses will lack genetic diversity, which can help them fend off disease or survive adverse conditions.
But Ailstock noted that many grass beds begin in isolated areas with only a few seeds or bits of a plant.
“There’s not that much genetic variability, anyway,” said Evamaria Koch, a scientist at the University of Maryland’s Horn Point Laboratory, who has adopted Ailstock’s technique to grow grasses. “So we don’t know whether that is an issue or not, but I have a feeling that it is not.”
Koch grew plants during the winter and spring. Then, they were taken from the jars and placed in ponds atop a coconut fiber “rug.”
The plants will grow and root in the rug which, this fall, will be “rolled up” and taken to the St. Mary’s River where it will be unrolled and anchored underwater as part of a grass restoration project being carried out by the Alliance for the Chesapeake Bay and the National Oceanic and Atmospheric Administration’s Chesapeake Bay Office. Ultimately, the plants will attach to the river sediment and the coconut rug will dissolve.
The drawbacks to the lab-rearing process is that it demands a lot of lab space, as well as test tubes and glass containers. Also, each plant from the wild has to be thoroughly cleaned in the lab — the test tube environment would also promote the rapid growth of any bacteria or contaminant that remains on the plants.
On the other hand, the technique is less labor intensive than traditional transplant efforts, which require people to dig up, move and replant grasses individually. Also, lab-grown plants have more intact root systems than those dug up in the wild.
“I think the technique definitely has a big potential,” Koch said. “It’s a matter of having the money to do it. It’s not cheap.”
But Peter Bergstrom, a biologist with the U.S. Fish & Wildlife Service who chairs the Bay Program’s Submerged Aquatic Vegetation Workgroup, said there may be potential for commercial growers to adapt the process.
“I get calls fairly regularly from people who just want to buy some plants. They don’t want to go dig them up somewhere,” he said. “They have money to spend and they want to do something good for the Bay. A lot will depend on whether there are enough people willing to grow them and if they can get the scale so it is commercially viable.”