MUSSEL RELOCATION
Mussels are an important part of a strong ecosystem
After 15 years of planning and consideration, we are finally taking the first steps to restore our namesake rapids. Mussel relocation is a monumental milestone for the project!
Up to four dive teams will be searching an area about the size of eight football fields for snuffbox and other common mussel species during the late summer and early fall months of 2024.
Mussels will be recovered, identified, counted, and marked for future monitoring before being relocated to alternative locations nearby that offer suitable habitat based on the species’ water flow and substrate type needs.
Why is this work necessary?
First and foremost, relocation of Federally Endangered mussels is required prior to the start of in-river construction. The project design has reduced the impacts to the endangered mussels to the greatest extent possible, but relocation is still required.
Secondly, improving the aquatic habitat for threatened and endangered fish and mussels species has always been a key goal of this project. Mussel relocation is one of the ways we’re doing just that.
Relocation Process
This is a very large and complex mussel relocation effort. The project area is larger than 45,000 square meters, roughly the size of eight football fields, and could require over 100 days of searching and relocation.
Four or more dive crews could be in the river from August through October collecting as many mussels as possible while diving and snorkeling. Collected mussels are identified, counted, and marked.
After processing, mussels are in mesh bags in flowing water until they are transported to recipient sites at Ada, Riverside Park, and Plaster Creek. Most mussels will go to Ada, as this bed has similar species, habitat, and evidence of recruitment.
Some species require special habitat these species need slower flowing areas and softer substrate available at Riverside Park. Other species are host specific and the fish host is not abundant upstream of the 6th Street Dam. These species will be placed in a bed near Plaster Creek.
Within the relocation sites, Michigan and federally endangered species are placed within a grid for future monitoring to ensure they survive. All other common species are spread throughout the mussel bed.
UPDATE: After 15 years of diligent and meticulous planning, the city of Grand Rapids and Grand Rapids Whitewater project team working to restore the Grand Rapids’ namesake rapids in the Grand River, has announced a monumental milestone. As of August 22, 2024, divers and biologists will being mussel relocation in the Grand River through October.
During the operation, up to four dive teams will search an area about the size of eight football fields for federally endangered Snuffbox Mussels (Epioblasma Triquetra), State threatened and endangered mussels, and other common mussel species. Mussels will be recovered, identified, counted and marked for future monitoring before being relocated. Crews will move each to nearby locations in the Grand River that offer suitable habitat based on the species’ water flow and substrate needs.
Learn more in the press release here.
Common Questions & Fun Facts
Can you eat them?
Native Americans used mussels as a food source. Young mussels may be edible. However, most mussels are several years old (2 to 100) and have been siphoning river water for some time. They would basically taste like rubberbands.
What are mussels good for?
When they were abundant in our rivers (100s/m2), they acted as the livers of the river. They siphon water, taking out algae, bacteria, and soil particles. What they don’t eat is packaged into pseudofeces. Pseudofeces are deposited on the river bottom and available for other aquatic animals to eat.
They in turn are eaten by fish species such as freshwater drum and river redhorse. Also eaten by mammals such as river otters, raccoons, and muskrats. The shells provide a solid surface for snails and other invertebrates to colonize, these are eaten by fish. The also act as “biological rocks”, to stabilize the river bottom.
Are these zebra mussels?
No! Freshwater unionid mussels are native to our rivers and lakes. They have been here since the dinosaurs. They have evolved with the river system, including the fish. Their life cycle includes a parasitic stage on fish. They live from 1 to hundreds of years, and some do not reproduce until they are 5 to 10 years old.
Zebra mussels are invasive. They come from Eurasia. They also siphon river water. However, they have not evolved with our river systems. They tend to overpopulate, die off, and cause fish kills. The good news is, if we allow our rivers to follow natural processes, unionid mussels will persist and zebra mussels will not overpopulate.
Fun Facts
- The Grand River historically supported diverse unionid assemblages, with at least 32 species reported in the Grand River. There is 1 federally threatened and endangered species (Snuffbox Mussel) that has been found in the project area. There are 15 Michigan threatened and endangered mussel species
- The project is also anticipated to have other benefits for state listed species of concern such as Lake Sturgeon and River Redhorse
- Mussels have no head, eyes, ears, or appendages—with the exception of a single foot, which they use to burrow down into mud or sand.
- Mussels use internal gills to filter food and oxygen from water.
- Mussels need a host fish to reproduce. Mussels release their larvae into the gills of host fish. After several days or weeks the juvenile mussels release from the fish and settle into their new home in the stream bottom.
- Mussels provide vital ecosystem services. One mussel can filter up to 15 gallons of water in a single day!