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TNC finds mussel success in Blue River

TNC finds mussel success in Blue River
TNC finds mussel success in Blue River
Two of 1,100 mussels tagged in 2015 in Blue River are checked during a follow-up last September. Researchers noted the mussels had more than doubled in size. Submitted photo

The Nature Conservancy, along with the Duke Energy Foundation and local fourth-grade students, tagged 1,100 baby wavy-rayed lampmussels for release into the Blue River back in September 2015. The mussels were then distributed equally at three different locations in the river.
The freshwater mussel project is one of the strategies in the Blue River Project to improve water quality. The mussels contribute their own brand of water purification by filtering up to eight gallons of water per day.
A year after the initial placement of the mussels, The Nature Conservancy went back to the three locations to see their results. At one of the locations, they were able to recover 80 percent of the tagged mussels placed there.
‘Initially, I was hoping for a 50-percent success rate,’ Cassie Hauswald, freshwater ecologist for The Nature Conservancy’s Indiana Chapter, said. ‘That would’ve been a good mark for us to hit, but 80 percent is fantastic.’
When recovering the tagged mussels, TNC teams also discovered the mussels had more than doubled in size.
‘That was a great sign,’ Hauswald said. ‘It means that the river is actually feeding them more than a lab setting.’
However, the two other locations did not see the same results.
One did show enough success to allocate more mussels, but not at 80 percent. The final location showed no sign of the tagged mussels. This does not suggest failure, Hauswald said. In a location with a strong stream, the baby mussels could have moved farther downstream and not allowed them to be located.
Freshwater mussels are the most endangered group of animals in the United States. This is the result of years of stress on freshwater mussels from the button industry, which harvested mussels for pearl buttons before plastics were widely available to industrial-age sewage going directly into the rivers to poor agricultural practices and leaking septic systems. Indiana originally had more than 75 species of mussels. Today, Hauswald said nearly 20 have been lost.
With the success of the beginning stages of the project, the Duke Energy Foundation has given The Nature Conservancy another grant to expand work in Blue River, as well as taking it to tributary rivers across the state that empty into the Wabash River.
‘We were trying to prove that this technique could work,’ Hauswald said. ‘Now that we’ve seen success in the 80-percent range, we plan on taking this technique to other rivers across the state.’
The Nature Conservancy has expanded its research in Blue River by adding additional mussels above the dam in Milltown. The mussel population above the dam has not done well in recent years, Hauswald said, and The Nature Conservancy is trying to introduce more genetic diversity in a location where that diversity is decreasing.
‘Freshwater mussels are resilient,’ she said. ‘What they tell me about the places where they are still found is that there is hope.’
The mussels will continue to be monitored during the next five years by The Nature Conservancy to track growth and survival rates. With continued success, The Nature Conservancy will help to bring freshwater mussels back to healthy habitats throughout the state.