Mussels Help Clean Up Chesapeake Bay

SCOTTSVILLE, Va. (AP) — It was only 3 inches long but one of the little James Spinymussels that moved from Charles City County far up the James River to Scottsville this summer can filter up to 15 gallons of water a day.

That’s a volume of water roughly a thousand times the size of that mussel, one of nearly 1,300 shipped from the Harrison Lake National Fish Hatchery this summer — and it’s why environmentalists now see the small shellfish as big helpers in their efforts to clean up the Chesapeake Bay.

To make sure the little guys find safe spots to settle, the Chesapeake Bay Foundation is using a new $73,800 grant from the National Fish and Wildlife Foundation’s new Chesapeake WILD program, along with $12,000 of matching funds to map stretches of bay tributary rivers and streams that provide good mussel habitat, to guide conservation efforts for Virginia’s 23 species — including the endangered James Spinymussel, Atlantic Pigtoe and Dwarf Wedgemussel as well as the threatened Yellow Lance and Green Floater.

The “Mussel Richness Map” will show where buffers of trees can best protect the shellfish from the pollutants in rain and snow runoff that can prove so deadly to them.

The map will serve a double purpose of helping target stretches of rivers and streams where planting buffers could be especially helpful to trap the sediment that clouds waters and kills plant life, as well as the phosphorus and nitrogen that feed the algae blooms that create dead zones in the bay.

“Eroding stream banks can bury mussels too deeply to dig out of, and trees provide shade — mussels are sensitive to temperature,” said Erin Reilly, senior staff scientist with the James River Association.

In tandem with the Chesapeake Bay Foundation’s mapping, the James River Association will develop a mussel restoration plan for the James watershed, with a $51,800 WILD grant and $25,000 of matching funds.

Mapping and planning will help the foundation and association identify the right kinds of river bottom and vegetation that different kinds of mussels prefer — generally, clayey ground doesn’t work, since freshwater mussels, unlike the edible blue-shelled mussels of the seashore, like to bury themselves.

“For some, sandy soil is good, others like pebbly or gravelly bottoms,” Reilly said.

Wherever they plant themselves — from way up in the mountain headwaters of the bay’s tributary rivers to just a bit downstream from Richmond, freshwater mussels can help clean the Chesapeake in a major — and until recently unexpected — way, said Joe Wood, senior Virginia scientist with the bay foundation.

Biologists’ latest research found that mussels accumulate significant amounts of nitrogen in their bodies, keeping it out of the water and from flowing downstream to the bay, he said.

Pollution and dams, the warmer water that climate change is bringing, as well as loss of habitat and disease have slashed freshwater mussel numbers in the Chesapeake Bay watershed. Scientists estimate the population is down 90% from the days European colonists arrived in the 1600s.

But the U.S. Fish and Wildlife Service’s Harrison Lake Fish Hatchery has released or given others to release about 86,000 mussels this year, including 2,437 James Spinymussels.

That summer trip to Scottsville for 1,300 James Spinymussels, though, marked a significant milestone.

They were the first to be planted in the James River itself — and the James Spinymussel hasn’t been found in the James for more than 50 years. They’re mainly found, when they can be found, in small streams in the James River watershed in Virginia and West Virginia, and in the Dan River watershed in Virginia and North Carolina.

A joint effort of the Virginia Department of Wildlife Resources and the U.S. Fish and Wildlife Service had been working toward that release in the James for more than two decades.

The two agencies are hoping the planting will be a step toward bringing the species back to its namesake river.

“It’s believed to have been lost over about 90 percent of its historic range, including the main stem of the James River,” Brian Watson, Virginia’s State Malacologist (mollusk scientist) has said.

“A lot of it probably had to do with pollution due to historic uses on the James River,” he said.

And that’s another bit of good news about mussels, said the James River Association’s Reilly.

“There’s no point in planting them if they aren’t going to survive,” she said. The fact that planted mussels are making it is a sign that the James is getting cleaner.

“We are making progress,” she said.