City required to relocate river creatures before any renovation work can take place.

Contributing to the multimillion dollar cost of the riverfront project that is planned in Hannibal will be a roughly $60,000 expense for the relocation of mussels.

The mussel-moving information was shared with the city council Tuesday night by Mark Bross of Klingner and Associates, the engineering firm that is assisting the city on the project.

Bross reported that moving the small river creatures will have to occur before any construction on the riverfront can begin.

“Some mussels are protected and they want them moved so they are not destroyed during construction,” he said.

According to the Missouri Department of Conservation, the state has nearly 70 species of freshwater mussels. Like all bivalves (such as clams, oysters), there are two protective shells, which are secreted, over time, by the soft, boneless animal inside. They range in size from only about 2 inches to a maximum size of 10 inches or more. As a general rule, larger rivers and streams support more species than smaller creeks. Nearly half of Missouri’s mussels are species of conservation concern.

Concern over the mussels was raised by the U.S. Fish and Wildlife during the comment period, which is part of the permitting process.

“That (comment period) is usually open about 30 days. Any comments the Corps of Engineers receives, they will provide to us. We have to either answer the questions and clarify things or provide additional information to address questions and satisfy the concerns of those agencies or the public. We’ve only received two comments so far and we have pretty much agreed on how those will be resolved,” said Bross, adding that the other inquiry was regarding information about the history of Nipper Park which came from the Missouri Department of Natural Resources’ State Historic Preservation Office.

From what Bross has learned about mussels they are not in short supply.

“They are along the entire length of our riverfront wall, about 1,100 feet,” he said.

A suitable site has been determined on where to put the mussels once they have been rounded up.

“We have agreed to an area that is south of Bear Creek where we will create a habitat for them using the boulder clusters that they require,” said Bross. “Boulder clusters are large boulders. The mussels like to sit down stream of those boulder clusters because they create a protective zone for them.”

Rounding up mussels is a unique skill. Because of that the city is carefully searching for the right contractor.

“We are actually getting some bids on that work right now. There are several environmental agencies that do that type of work,” said Bross, who estimated the cost of relocation will run between $60,000 and $70,000.

According to Bross, the work will be done later in the year.

“They don’t like to do it when it’s cold. It will be prime time to do it this summer. Late summer would be perfect,” he said, adding that once the work begins it will take approximately two months to complete.

Having to relocate mussels did not come as a shock.

“It was kind of expected,” said Bross. “There were some other concerns we had because we’re taking the old marina and filling it in and creating a new marina. We were worried that they might get comments about fill in the floodplain, but they didn’t comment on that.

“We actually felt that the process went better than expected to be honest with you.”

Reach reporter Danny Henley at danny.henley@courierpost.com