From the shore of the Anacostia River, clusters of water stargrass and hydrilla could be seen swaying just beneath the water’s surface near Buzzard Point, the southernmost tip of the District of Columbia.
This submerged aquatic vegetation was a good sign for the group of people stepping into waders on the shore on a hot afternoon in early September. The Anacostia Watershed Society’s truck bed was full of wild celery, an SAV species that once grew in the Anacostia, and one they’d like to see return as both a contributor to, and harbinger of better waters.
The day before, the watershed society staffers harvested both seeds and adult plants from Mattawoman Creek, about 30 miles downstream on the Potomac River, and brought them here for transplantation at low tide, with hopes that the river would embrace the plants as it has before.
Similar grass transplanting projects — carting species from healthy ecosystems to those that are more polluted — have taken place throughout Chesapeake waters with mixed success. Such projects have grown in popularity alongside a body of research that says the grasses are key to providing underwater habitat, pollution filtration and other ecosystem benefits.
But can the Anacostia River, the washbasin of the Bay’s most populated areas, support them?
For these nonprofit staff and volunteers, seeing other SAVs — even nonnatives like the hydrilla — thrive below the surface of Anacostia waters is a good sign that it could.
“What’s interesting is SAV can be an indicator of the improvement of the Anacostia,” said Dick Hammerschlag, who worked with SAV species throughout the watershed during stints at the National Park Service and U.S. Geological Survey before retiring. He was there to lend a hand and keep tabs on the fledgling SAVs in the Anacostia.
“Right now,” he said, “I’m interested in what they can do in the Anacostia, especially trying to move upstream.”
Hammerschlag was quick to point out that the waters we were seeing here weren’t the “true blue — or true brown” Anacostia. The junction with the Potomac was a stone’s throw away, and the bigger river’s cleaner waters flowed easily into this part of the Anacostia.
That could help these early SAVs take hold and perhaps spread their seeds to other parts of the river that are just clean enough to support them. The AWS planted another batch of wild celery farther upstream in the river’s Kenilworth and Kingman marshes, where they can piggyback off the success of emergent grass beds — those that are partially underwater in marshes and along shores.
Emergent grasses, such as bulrush or lizard’s tail, aren’t as dependent on clear waters as submerged grasses. Having the latter thrive in the Anacostia River is a gamble — but one that would earn a gold star for its ongoing cleanup efforts.
“We’re running into that chicken and the egg situation,” said Audrey Pleva, a part-time natural resource technician at the AWS who helped to start the plantings as a Chesapeake Conservation Corps volunteer this summer.
“SAV filters the water, reduces the turbidity and keeps the water clear — but you also need clear water to let it grow. So we had to wait until all of our other efforts boosted the water clarity so we could do it.”
Water advocacy groups have been gaining momentum in their work with Maryland’s Prince George’s and Montgomery counties and the District of Columbia to enact water quality legislation, reduce polluted stormwater overflows and add green infrastructure throughout the river’s watershed.
But those efforts are often hard to see after a heavy downpour, which not only washes trash and sewage into the river but also cranks up erosion and churns up sediment — turning the river water brown.
Such a rain would be a death sentence for SAVs if they were in certain parts of the river. Pleva said the river’s uncertainty is one of the reasons they decided to use wild celery, or Vallisneria americana, a robust native species.
But deciding where to plant these batches was the hardest part, she said.
Boat drivers don’t want SAV, which sends flowing fronds to just below the water’s surface in the middle of the river, where they guide their boats. Tributaries are a logical place for such plantings, but they are often the cloudiest portions of the river.
Pleva said the plantings needed to take place near the shores of the river’s mainstem that have mostly clear water and depths of 1–4 feet, depending on the tides. She worked with bathymetry maps produced by the consulting firm Tetra Tech to zero in on suitable spots.
“We landed at Kenilworth, because that’s where we do a lot of our emergent plantings, so we know that the SAV can thrive off the filtering from those restoration efforts,” Pleva said of the first smaller clusters of wild celery plantings, which were also planted in the marsh near Kingman Island.
A similar synergy led her to the site near Buzzard Point, where DC’s Department of Energy & Environment (formerly DDOE), had planted two small batches of wild celery in recent years.
Pleva also looked to the department’s planting methods for cues to protect the grasses from predators — namely the canvasback duck that likes to eat the grass so much, it shares its name (Aythya valisineria).
She borrowed the DOEE’s idea to build floating cubes of protection out of PVC pipe. Before planting the wild celery, she and a few other AWS staff members snapped the plastic “cages” into place and carried them through a small opening in the trees.
Each cage measured 5 cubic feet, and four were linked to accommodate the large planting. Pleva planned to plant about 200 square feet of wild celery that day, or 500 plants, by hand-digging small holes and inserting the root clusters at low tide. The cages were then covered with orange snow fencing to both keep the birds out and make them visible to boaters.
This planting near Buzzard Point was Pleva’s third this summer. She moved quickly to get the crew into waders and into the water while the tide remained low. She pulled a root cluster from a plastic bucket that held the wild celery — which still looked vibrantly green despite being a fish out of its native waters — and reminded her fellow staffers about how deep to plant them.
The plantings were funded in part by the National Fish and Wildlife Foundation, and the AWS will be back to monitor their progress in coming months. Success, Pleva said, would be measured in the number of plants that survive and multiply and in clearer water with more dissolved oxygen.
“If the project is successful, we will be on to something really exciting for the river,” she wrote in a blog post about the project.
Bob Murphy, fisheries ecologist at Tetra Tech, Inc., observed the planting with Hammerschlag from the shore and was optimistic about its prospects.
“It’s not going to be possible to plant the entire Bay or the entire river” with underwater grasses, Murphy said. “We do projects like this to establish seed sources, and if you get a smaller population established, it will expand.”
“You’re giving the river system a jump-start.”