Fisheries Division works to protect endangered mussels
Nov. 7, 2013
Bring up the Department of Natural Resources' Fisheries Division and most people immediately conjure up images of high-profile game fish -- Chinook salmon, muskellunge, walleye -- and what it takes for the hatchery section to churn out enough fry to keep those fisheries booming in Michigan.
But Fisheries Division is also concerned about aquatic species that are not quite as visible on anglers' radar. Resource managers will go to great lengths to ensure the well-being of those critters, too.
Need an example? How about the snuffbox mussel, for starters.
A smallish (up to about 2 inches) freshwater bivalve that inhabits sand, gravel and cobble substrates in swift-flowing, small- to medium-sized rivers, the snuffbox mussel (Epioblasma triquetra) is sensitive to siltation and disturbance. It has been on the state's endangered species list for a number of years and has recently become a major player in some of Fisheries Division's long-term management plans.
For many years, Fisheries Division has had removal of the Lyons Dam on the Grand River on its wish list. The 156-year-old Ionia County dam, which generated electricity until 1959, has been owned by the village of Lyons since it went out of commission and was deeded over by Consumers Energy.
Considered to be at risk for failure, the village has targeted the dam for removal for years, seeking grants to facilitate the work.
"We funded the design work for removal at least five years ago," explained Scott Hanshue, a fisheries biologist who has taken the lead on the Lyons Dam removal. "The Ionia Conservation District, working with the village, got the grant and hired an engineering firm."
The original removal plan, however, had to be modified because of some potential erosion issues. The plans have changed a couple of times, Hanshue said, but ultimately it was decided to remove about two-thirds of the height of the dam and build a rock ramp that would allow for fish passage and eliminate the need for the fish ladder.
Just under a million dollars has been appropriated from the state's dam removal fund to pay for the work.
Hanshue went to the site and surveyed it with Daelyn Woolnough, a freshwater ecology professor at Central Michigan University. They found a couple of species of mussels that are on the state's endangered list -- Lilliput and black sandshell mussels -- though neither is federally listed. But they also found the snuffbox mussel, which was added to the federal endangered species list in 2012.
"That's a huge hurdle to jump over," Hanshue said.
As a result, the DNR contracted with CMU to do a much more extensive survey. Survey crews grubbed through the sediment by hand as well as used snorkel and scuba gear to search for the snuffboxes. They located 71 live snuffbox mussels, all of which were marked with PIT (pass integrated transponder) tags and replaced where they were found in the river. The PIT tags will allow workers to locate them again in the future.
Researchers are currently crunching CMU's survey numbers to develop a population estimate for the snuffbox mussels. Once that process is completed, the population estimate will be submitted to the U.S. Fish and Wildlife Service, which will permit the dam removal to continue.
"Prior to constructions, the mussels will be found and relocated," Hanshue said. "We knew it was likely that we would have to relocate all the mussels within the footprint of the project, so we've been looking for suitable locations for the relocation effort. We thought we'd go upstream from the dam, but that habitat is not conducive to snuffbox mussels. But we have now found some suitable habitat downstream, so we know we'll be able to put them there."
In addition, it's likely the Fish and Wildlife Service will require some monitoring activities as a condition of the dam removal, Hanshue said. That will further add to the cost of the project, but worth the effort to protect an endangered species.
Despite the delays and cost overruns associated with this dam removal, state fisheries officials are taking the Monty Python approach -- always look at the bright side -- to the situation.
"We're going to get some valuable data on the mussels," Hanshue said. "The Grand River is one of the strongholds for the snuffbox mussel in the country, particularly between the Lyons Dam and just downstream of the Sixth Street Dam in Grand Rapids.
"The listing of this mussel is going to affect a lot of future projects."
And that is all part of Fisheries Division's mission. Once the dam removal is complete, the river will function better and fish will be able to move up and downstream more easily. But the endangered snuffbox mussel will also have a better chance of thriving in one of its last remaining strongholds in North America.
To learn more about Fisheries Division's production, management and research work, visit www.michigan.gov/fishresearch.