Grand River Smallmouth Bass
Bunt, C.M., S.J. Cooke and D.P. Philipp. 2002. Mobility of riverine smallmouth bass related to tournament displacement and seasonal habitat use. Black Bass 2000 Symposium. American Fisheries Society Symposium 31: 545-552.
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 of 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.
Cooke S.J., C.M. Bunt and R.S. McKinley. 1998. Derby-determined vital statistics and trends of the smallmouth bass, (Micropterus dolomieu), recreational fishery in the middle reaches of the Grand River, Ontario. Canadian Field-Naturalist. 112: 451-458.
Data from Grand River Bass Derbies (1988 – 1997) documents trends in relative abundance and provides information on vital statistics of smallmouth bass (Micropterus dolomieu) in the recreational fishery on the Grand River, Ontario. The length-weight relationship for all fish entered in the derby was described as weight (g) = (2 x 10-5) x total length (mm)2.95. A significant declining trend in mean length existed for the 10 longest fish entered in the derby each year over the 10 year period (r 2 = 0.071, p < 0.05). Relative weights observed were consistently below the length specific standard of 100, similar to other riverine smallmouth bass populations. Age and growth rates were similar to other northern riverine smallmouth bass populations, and the oldest fish observed was 16+ (441 mm TL). Trends in the middle Grand River Catch Per Unit Effort (CPUE) data suggest that the relative abundance of smallmouth bass has decreased significantly since 1988 (r2 = 0.552, p < 0.05), although the 10-year derby CPUE (0.36) is similar to CPUE from other riverine populations. The derby data suggest that the population size and structure require further investigations to determine exactly where problems and management opportunities exist.[/cs_content_seo]