In Canada, the western ridged mussel (WRM; Gonidea angulata, Lea) is only found within the Okanagan Valley, British Columbia, and is listed on both provincial and federal levels. A possible threat to this species is invasive plant (Eurasian watermilfoil, Myriophyllum spicatum, L.) control, through rotovation of the lake bottom. We investigated the impact of rotovation and found that: 1) Experimental rotovation resulted in WRM being crushed at the rotovation site while no mussels were crushed at the control site. One day after rotovation, we found significantly more dislodged WRM at the experimental than control site, which disturbs the natural behavior of the mussel. At the same time, we recovered significantly fewer live WRM at the experimental than the control site. This difference was likely explained by the burial of WRM, which we argue has a negative impact on mussel survival. Four months after rotovation, we recovered significantly fewer WRM at the experimental than control site, indicating that the rotovation had a long term negative effect on the mussel. 2) Surveys of WRM habitat showed that the mussel was more common at non-rotovation sites. At rotovation sites WRM was only found in areas that had not been rotovated recently or that are inaccessible to the rotovator. Overall, the experiment shows and the surveys indicate that rotovation has a negative impact on WRM. Based on these findings, resource managers should avoid using rotovation in areas where freshwater mussels are present.