Collaborative Mussel Project

Hatchery staff and TWRA Cumberland River Aquatic Center (C-RAC) are working to fill the Dale Hollow NFH boat house with as many grow-out populations of wavy-rayed lampshell, birdwing pearlymussel, and round hickorynut mussels as possible. The grow-out cohorts this year are progeny derived from the intensive culture efforts rather than the captured manual fish infestation previously employed to populate the rearing structure.

The controlled approach has a number of advantages:

• Eliminate potential introduction of invasive vertebrates
• Eliminate potential introduction of unmonitored genetics
• Removes all horizontal disease transmission potential
• Shifts stu dies from random to fixed/monitored allowing for real-time introduction of different control elements
• Adds predictability and structure to support, cleaning, inventory, and stocking requirements
• Increases potential future rearing capacity

TWRA conducted a full inventory this month and decided to hold the remainder of the mussels at Dale Hollow through the winter. The goal at Dale Hollow remains to try to fill the boat-house to max capacity, but we only reached 25% fill this year.

Next year’s plan is to:

• Request some central coordination assistance
• Collaborate with the growing friend’s group and local US Army Corps of Engineers to build some infrastructure improvements
• Power supply line repair (240v)
• Working plank expansion
• Small sampling craft
• Completion of winch suspension system
• Building out more cages

End of Year Retention Summary

2023 Mussel Update

This year's list of the newly added or new rearing method experimental mussel lots:

29 - Duck River dartersnapper (Epioblasma ahlstedti)

40 - Sheepnose (Plethobasus cyphyus)

110 - Round hickorynut (Obovaria subrotunda)

2,388 - Pale lilliput pearlymussel (Toxolasma cylindrellus)

6 - Rough pigtoe (Pleurobema plenum)

15 - Pink mucket pearlymussel (Lampsilis abrupta)

271 - Cumberland moccasinshell (Medionidus conradicus)

6 - Purple cat’s paw pearlymussel (Epioblasma obliquata)

Tennessee Wildlife Resource Agency mussel crew with station staff labor assistance had double the walking and working space this year making the mussel work far easier, safer, and faster. The deep clean and organizing really helps the process and having a pressure washer and tools to clean/repair cages on site allowed for immediate turnaround re-use easily saving two days of labor hauling everything back and forth, setup, and cleanup. The majority of the mussels initially planted this year are the result of the invitro rearing at the Cumberland River Aquatic Center using fish blood from a number of host species. This was followed up by the rapid building of a new cage and planting some infested host fish a few days later.

We have a few thousand specimen on station being reared for grow-out that we will harvest, count and return to rivers in mid/late September.

The Boat house upgrades where done using mostly physical labor and as little money as was reasonable - we had to buy a low cost 110v sump pump and electric pressure washer to clean the cages, but most of the fabrication for the new working plank, barge, hoist rail system and building organization was done with on-station supplies or donations from the hatchery friends group.

The cages at Dale Hollow have been on the repair list for over a year as the original cage metal is rusting out and dangerous to handle, cutting anyone that touches the material with bare hands. We’ve been re-building cages every couple weeks and trying out a number of pre-made alternatives. So far nothing compares to quality available with using the aluminum frames. The perforated screen material makes lifetime quality cages but is costly to produce. The station is using a combination of short lifespan siding materials and as funds and spare aluminum is available building the higher quality perma-cages. Staff will continue to experiment if fabrication, innovation, and off the shelf alternatives and has generated a combination cage inventory summary and funding assistance solicitation.