Mobility of riverine smallmouth bass related to tournament displacement and seasonal habitat use

Mobility of tournament-caught and released smallmouth bass Micropterus dolomieu was monitored in the Grand River, Ontario, between 1995 and 1999 using radiotelemetry and mark-recapture. Smallmouth bass (n = 18, size range 313-486 mm TL) captured and radiotagged following the tournament remained in the. immediate release vicinity for extended periods (mean 54 days, median 30 days). Four fish released at the site of original capture generally remained sedentary for the duration of the study (i.e., 11 months). Five of fourteen displaced smallmouth bass with radio tags returned to their original site of capture and-one bass with an external numbered plastic tag returned over a distance of 26 km. Smallmouth bass moved upstream and downstream to overwintering areas, characterized as low velocity pools, where numerous fish aggregated. Anglers recaptured twelve percent, or 13 of 108 externally tagged smallmouth bass. Maximum, distance between release and recapture was 84 km for externally tagged fish. Over half of recaptured fish were caught at the release site, and most were recaptured within one week of release. Organizers of competitive angling events in river systems should consider releasing fish near sites of original capture or in areas that are not readily accessible to minimize angling vulnerability immediately after tournaments.