(ABC 6 News) – For the past five years, two organizations have been reintroducing two species of mussels – a type of mollusk similar to clams – back into the waters of the Cedar River in Austin, and they’re finally seeing results.

The project started in 2019, when the DNR began growing and harvesting several species of native mussels to replace the populations that had been lost over time.

In the Cedar River, that means black sandshells and muckets, both of which disappeared from the area over the last few decades.

“Essentially, over the years, they got over-harvested and their populations just didn’t rebound fast enough,” said Lindsay Ohlman, senior propagation biologist for the DNR’s Center for Aquatic Mollusk Programs.

In the late 1800’s and early 1900’s, native mollusks were a popular material to use for buttons in clothing, which led to their decline.

But pollution and dams built along the river also spurred along the process.

It’s not just bad for the mussels, but for the water itself.

“Their main job is to filter water,” said Ohlman.

They do that job well, each filtering a gallon of water every hour.

“These mussels out in nature, they normally exist in big clusters, big mussel beds,” said Ohlman. “So there’s thousands and thousands of them all together. That’s a big help for cleaning the water.”

That partnership is also seen in the people that care, especially when it comes to the Cedar River Watershed District and the DNR.

“We do what we can on our end but the DNR coming in with this kind of project, which is literally reviving the natural mussel population in the Cedar River, is incredible,” said Outreach & Water Plan Coordinator for the CRWD, Tim Ruzek.

Along the Cedar River, these mussels play just a small part in bringing the environment back to a health and stability it hasn’t seen in a long time.

“We hope the mussels along with some of the various practices that we’re working with farmers and landowners on in the countryside all help improve the water quality, reduce erosion (and) reduce the amount of pollutants in the water,” said Ruzek.

That means a better river for anyone to use.

“(The mussels) are attracting other invertebrates and other fish, and that equates for better fishing opportunities for people and cleaner water for people that use the Cedar River,” said Ohlman.

Though it may take some time, the benefits will be well worth the wait.

The entire project has seen over 7,000 individual mussels re-enter the Cedar River over the last five years.

Ohlman and her team say they are already seeing mussels they’ve introduced in previous years reproducing, which will go a long way towards establishing these vital pieces of the ecosystem.

“What we are doing now for mussel conservation will have lasting effects into the future,” Ohlman said.