Results from Plantings of Marked Fingerling Brook Trout (Salvelinus f. fontinalis Mitchill) in Hunt Creek, Montmorency County, Michigan

Abstract

Fin-clipped fingerling brook trout (Salvelinus f. fontinalis Mitchill) both hatchery-reared and wild, were released in Hunt Creek in late summer or fall of 1939 and 1940. Their contribution to the catch in subsequent years was determined by creel census and anglersˈ reports. The extensive experiments involved release of 35,109 and 17,635 marked fingerlings, respectively, throughout the length of Hunt Creek. Marked fish entered the anglersˈ catches in 1941 and 1942, and made up from 0.27 to 2.56 percent of the observed catch of legal brook trout in various years. The total known percentages of recovery were 0.07 percent (26 fish) of the 1939 release, and 0.28 percent (49 fish) of the 1940 planting. Intensive experiments with both wild and hatchery-reared brook trout fingerlings marked by different fin combinations were carried on simultaneously in Section C of the experimental waters of Hunt Creek. Marked hatchery-reared fingerlings released in 1939 contributed from 0.0 to 0.26 percent of the total observed catches of legal brook trout in later years; 1940-marked hatchery fingerlings made up from 0.00 to 0.45 percent of total observed catches in later years. Wild fingerlings marked at the same time made up from 0.00 to 1.80 percent of catches recorded in subsequent seasons. Larger percentages of recovery were noted for the smaller of the two releases (1940). Through the use of the formula M = 1,000 A/BC where M = migration or abundance index from a release locality to a recovery locality, A = number of marked fish recovered in a given locality, B = number of fishing units of effort in a given locality, and C = total number of marked fish released in a given locality, it was demonstrated that the majority of wild and hatchery-reared marked fingerlings in the intensive experiment stayed within the limits of the experimental sections, although they did move out of Section C, except for the hatchery-reared fingerlings recovered in 1942, which were farther downstream than usual. General growth data on marked fingerlings of both types indicated that probably those fish which were largest at the time of marking and release came into the legal catch first. It was concluded that brook trout fingerling planting is a wasteful procedure because a low percentage reaches the anglersˈ creels. Creel census data demonstrate that despite the elimination of fingerling stocking in Hunt Creek following 1940, angling quality has not deteriorated.