Michigan Department of Natural Resources
Fisheries Research Report No.1807, 1973

The Effects of a Flies-Only Fishing Regulation Upon Trout in the Pigeon River, Otsego County, Michigan


W. C. Latta


       Abstract.-The effects of a flies-only fishing regulation on the catch and standing crop of brook (Salvelinus fontinalis) and brown (Salmo trutta) trout were measured in experimental sections C and D (2.3 miles) of the Pigeon River in 1958-64. During these years the minimum legal size was 9 inches total length and the creel limit was 5 trout. For the years 1951-57, before the flies-only regulation, any lure was permitted, and the creel limit was 2 trout in 1951-54 and 5 trout in 1955-57. The size limit was also 9 inches throughout the period 1951-57. Because of environmental variability, a ratio was used to relate experimental sections C and D to control section B,, the river section immediately downstream. In Section B (1. 2 miles in length) the regulations were a minimum length of 7 inches, a creel limit of 5 trout, and no restriction as to lure used for the test years 1951-64. Of the various aspects of the catch and standing crop analyzed, only the catch of brook trout (in numbers and pounds) and the number of young-of-the-year brook trout were statistically significant. None of the brown trout parameters was significant. For the brook trout, fewer fish were caught during the years of flies-only, 1958-64, than during the before years, 1955-57 (or the combined years, 1951-57), probably as a result of the decreased fishing pressure. The young trout were fewer in number during the years of flies-only, 1958-64, and during the years 1951-54 (under a 2-trout limit, any lure), than during the years 1955-57 (under a 5-trout limit, any lure); there is no obvious explanation. Fishing pressure in hours in sections C and D declined 44% under the flies-only regulation from 1955-57 to 1958-64. The slight increase in the catch per hour per trip, from 0.06 to 0.07 trout, was not statistically significant. The increase in the creel limit from 2 trout to 5 did not increase the total catch nor significantly decrease the percentage of successful anglers.