Wildlife experts are relocating nearly half a million mussels to make way for the new I-74 Bridge.
The massive project, which began on Monday, August 1, 2016, is expected to take until mid-October to complete.
"It's a very huge project," said Heidi Woeber, a biologist with the U.S. Fish and Wildlife Service.
Over the next two-and-a-half months, crews will remove approximately 450,000 mussels from the direct impact zone of the new bridge piers. Construction of those piers is scheduled to begin in Spring of 2017.
In order to retrieve the mussels, a team of commercial divers must work from a barge off the Moline shoreline. The divers work in almost total darkness, staying underwater for four hours at a time.
"The visibility's probably about 3 to 6 inches down there, so you could put your nose on the ground and not see anything. What we're doing is basically diving by braille -- we're down there feeling and seeing what we find," explained the dive captain.
Above water, other people separate the live mussels from the empty shells. A malacologist, or mussel expert, then transports the mussels by boat to a crew on the riverbank.
On shore, crews work quickly to identify and mark all of the mussels with an engraving tool. Based on previous surveys, experts expect to find five protected species among the mix.
However, all mussels -- regardless of species -- will be relocated.
"They're excellent indicators of water quality. They're one of the few species that actually filters and cleans and improves water quality," said Woeber. "Mussels have been used for medical research actually. So every time we lose something like that, we lose the potential for that species to improve our lives."
The mussels will then be relocated to one of three different beds of equal or better quality within 24 hours.