The speed that water moves impacts settlement and attachment of zebra mussels and plays a role in their ability to feed.
Settlement and Attachment
Juveniles will settle in internal piping and along any submerged area with a flow rate of less than 1.5 m/sec (Claudi and Mackie 1994). Zebra mussels avoid such high-velocity flow locations and typically will detach from such a poor settlement location and move (e.g., crawl, float) to a more suitable site.
Feeding
The laboratory feeding studies of Ackerman (1999) have indicated that the ability of dreissenid mussels (both D. polymorpha and D. bugensis) to clear plankton can be affected by water velocity. Increasing ambient velocity up to approximately 10 cm/sec led to increased clearance rates by the mussels, but the higher velocity of approximately 20 cm/sec was inhibitory and resulted in reduced clearance rates. Although there were no detectable differences in the clearance rates of D. polymorpha and D. bugensis of equal size tested at approximately 10 cm/sec, large mussels of both species had greater clearance rates than small ones.