Atlantic populations are highly significantly differentiated from a NE Pacific population so an unique biological stock in the NW Atlantic is considered to exist (Cassista and Hart 2007). The Department of Fisheries Canada (DFO) assesses the species in two units: Banquereau (Nova Scotia) and Grand Bank (Newfoundland) but both are managed under the Offshore Clams Integrated Fishery Management Plan, Maritimes and Newfoundland and Labrador regions (DFO 2010).