The James River gained over a thousand new mussels Wednesday and no it hasn’t been hitting the gym. The James spinymussel hadn’t been seen in its namesake river since the 1960’s, until a collaboration between the Virginia Department of Wildlife Resources and the U.S. Fish and Wildlife Service culminated in the release of about 1300 of the freshwater mussels.
The release is an effort to restore part of the river’s ecosystem function and recover this rare species, said Brian Watson, the state malacologist for the Department of Wildlife Resources.
“[The] James spinymussel has been a priority species I’ve been working with for my 20 years at the Department of Wildlife Resource. It’s been a goal of mine to try to reintroduce them to the main stem James,” Watson said. “Without being able to do that we probably can't really recover the species.”
Freshwater mussels work as a sort of purification system for the river. A single mussel can filter up to about 1/2 gallon of water an hour or 10 to 15 gallons a day. While there have been as many as a dozen species of freshwater mussels in the James river, surveys conducted in 2011 and 2012 found only seven.
The mussels being introduced to the river have been growing at Harrison Lake National Fish Hatchery since 2019 where efforts have been made to enhance propagation methods. Project leader Rachel Mair has been working on those methods since 2008.
“It's a very difficult species to grow because they require host fish that are very sensitive that you have to go out and collect, and they don’t like to be collected and they don’t like to be in captivity,” said Mair. “It’s taken us many years to get the technique down to where we can grow a lot of them, and grow them large enough to be able to put a tag on them and to release them.”
Each of the James spinymussels that was released is labeled and tagged with Passive Integrated Transponders, or PIT tags, so that the population can be tracked. Once found, the mussels will be measured to see if they have grown. The hope is that mussels without tags are found which would indicate that the population is growing on its own.
Mair is optimistic.
“Having an opportunity to release in the main stem of the James river for this mussels species is huge. It opens up a ton of available habitat that we wouldn’t have had otherwise,” she said.
Part of the reason that the mussels are able to be reintroduced to the river recently is because of the good water quality.
“Being able to put mussels here does speak volumes as to the condition of the river,” Mair said. “Mussels aren’t usually found in streams that have bad water quality.”
According to Watson, industrial discharge from the mid-1900’s is responsible for poor water quality that led to the near demise of the James spinymussel. While the water quality has improved over the past few decades, the efforts of this collaboration to increase the freshwater mussel population should help raise it even higher.
“It’s definitely exciting to release these mussels out to the river today. This is definitely not by any means the end of the story. This is a big hurdle [overcome] to get them back in the river,” said Watson.