Lake Tahoe native mussels being relocated to protect species

Quagga mussels have been getting all the press lately because of the looming threat to Lake Tahoe but this week it was the river mussel's turn for some attention.

Native to the western U.S., the river mussel is now a protected species due to their population being threatened by dams, habitat modification due to the disappearance of Lahontan Cutthroat Trout from the Upper Truckee and other river habitat changing occurrences.

There are only about 12,000 river mussels left in the Tahoe Basin, and they are all living in South Lake Tahoe along the Truckee River. The mussel is an important part of the aquatic food chain as they are filter feeders who's waste works into the sediment of rivers.

Humans are also a threat to the river mussel. According to Sarah Muskopf, biologist with the U.S. Forest Service, people are pulling the fresh water river mussels out, thinking they're doing the right thing and removing an invasive species. Problem is, the river mussel is not invasive.

There is a big difference between the native mussel and the invasive mussel. River mussels are larger and adults can be 3.5" to 4" in size, while while the quagga mussels are about the size of a finger tip.

"They shouldn't be confused since they have a much different size," according to Muskopf.

River mussels can have a life span of 80-100 years. As a larvae they live for about a month attached to fish gills. This is where the demise of the Lahontan Cutthroat Trout has been so detrimental to the mussel population as their flowing through the cold fresh water of the Truckee River allowed for a healthy beginning. Now they attach to any fish gills they can find, which is hard currently in the river. After a month, the mussels live in the substrate until big enough to intake food.

In a healthy river system there should be 100 river mussels per square meter. In the Upper Truckee there are about 20 per square meter.

The Brown Trout that exists in the basin today can be very territorial, and while they won't bother the larvae on their gills, their behavior causes fewer fish to be around for them to attach to. There will be a pair of Brown every 50-60 meters of river while the Cutthroat existed in large numbers along the whole river. (Scientists are trying to bring back the Cutthroat in experiments in Fallen Leaf Lake, which would present another problem if successful in that they threaten the Rainbow Trout).

The Forest Service is currently moving 7,400 feet of the river channel is being moved in order to restore the Upper Truckee River and the surrounding terrain and bring it back to being a thriving stream zone. There has been erosion along the river for years, causing steep banks and preventing flood waters from cresting over the bank.

Because the water will be cut off to the current stream in 2016 (and dirt going in), what to do with the only surviving native mussel population in Lake Tahoe had to be decided.

A pilot project is going on at the Truckee River project near the Lake Tahoe Airport. Some 900 river mussels are being removed from a portion of the river near the airport and being relocated to different spots along the Truckee River and Trout Creek.

To remove the mussels, divers go into the water, remove 20 mussels at a time, then bring them to shore. There, a team sands down the shell a bit so they can apply super glue, then a number is placed on the glue. The mussel is weighed and measured and placed in a bag in the river. Once all 20 go through this process the bag is tied up and they move onto the next location.

At the end of the day, the bags are collected and moved to their new home.
The team demonstrating the process Wednesday were Mason Bindl, the diver, Erin Miller who normally goes into the water but took time out of the water to explain the process, recorder Maura Santora, Cody Bear from the California Tahoe Conservancy and Phil Metting Van Rijn who is a volunteer and developed an app to aid in the tracking of the mussels. He owns a second home in South Lake Tahoe and traveled form his San Francisco home where he is a software engineer with People Soft.

Starting in October, staff will go to the mussel's new homes and monitor their progress. Next spring, weight and size will be recorded to see how they handled the move.

If successful, next summer the Forest Service will move the whole population (12,000) ahead of the river project completion. According to Theresa Cody, the U.S. Forest Service Project Leader for the restoration project, there will be a large scale relocation next year and many volunteers will be needed.

If the project demonstrated today isn't successful, then the Forest Service will have to decide the next step.The river mussel relocation project is being funding through SNPLMA, the Southern Nevada Public Land Management Act.