Abstract: Alewives (Alosa pseudoharengus) are anadromous fish that often encounter fishways when migrating upstream to their spawning habitat. In partnership with Ducks Unlimited Canada, we are quantifying attraction efficiency, passage efficiency and time of movement of alewife through fishways. To do this we tagged 790 fish with Passive Integrated Transponders (PIT) and tracked their movement through two Denil style fishways. Overall attraction efficiency to fishways was 44%, but passage efficiency was ≥74%. Tagged fish were most active at dawn and dusk. Tagged alewife detected at the base of the fishway were significantly longer than undetected individuals, and may have been experienced migrants. Our data suggest that quantification of the number of migrants that are motivated to attempt passage of fishways has implications for measures of true fishway attraction and passage efficiency for defining “effective fishways”.