-Two areas used in Davis' DNR mussel survey (1994) IC and ID were selected because of their proximity to the Northfield Dam.
-Sites for sampling within each of these two areas were determined using a random number generator prepared with PASCAL computer programming.
- Survey sites were classified by their distance from the dam, as well as their distance from the shore.
-The sites' proximity to either bank were designated qualitatively: right, middle or left part of the river (facing downstream).
-In this survey quadrats constructed from PVC piping were used to limit searches. (Quadrats were 1 m2 and joined together in a grouping of four, allowing divers to search 4 m2 at each location)
-Survey sites in each area the Cannon River were found using a Bushnell laser sighter and marked with flags.
- Upon reaching a given site via flat-bottom boat, anchor was dropped and search preparations were made.
-The temperature of air and the water were measured.
-Two divers wearing SCUBA gear entered the water, placing the quadrats on the substrate of the river.
-The quadrats were stabilized at the corners by small mushroom anchors; in areas of rapid current, anchors with ropes were dropped in front of the quadrats to support the divers while searching.
-Divers thoroughly searched all 4 m2 quadrats by hand and sight. Any mussels found were removed from the sediment.
-Specimens were put in mesh bags and given to a worker in the boat who quickly measured the mussels and returned them to the divers.
-Mussels were replanted in their quadrat of origen by inserting them in the substrate with the umbo facing downstream and the siphons up.
Note: Permits are required for this type of survey work. We acquired our permit from the Minnesota DNR through Bonita Eliason