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Returns from Plantings of Legal-Sized Brook, Brown and Rainbow Trout in the Pigeon River, Otsego County, Michigan

1953; Wiley; Volume: 82; Issue: 1 Linguagem: Inglês

10.1577/1548-8659(1952)82[265

1548-8659

Edwin L. Cooper,

Fish Ecology and Management Studies

A complete census of fishing on 4.8 miles of the Pigeon River, together with population estimates made at the end of the open season, made possible an accurate evaluation of the yield and survival of open-season plantings of hatchery trout. Fishing intensity in this research area for 3 years averaged 2,414 daily trips per year which was equivalent to 278 hours of fishing effort per acre per year. Sections in which hatchery fish were planted attracted about three times as much fishing as did the unplanted sections. Fishing quality, measured by the catch per hour per fishing trip, was generally poor for native fish, averaging less than 1 fish for 5 hours of effort. Hatchery fish made up about 70 percent of the total catch for the 3 years. Planting trout from a live-crate a few at a time (scatter-planting) did not prove to be advantageous over the practice of liberating large numbers of fish in one hole (spot-planting). Trout that had been scatter-planted did not contribute to the catch for a longer period of time, and produced fewer successful fishing trips, fewer total fish returned to anglers, and slightly fewer anglers sharing in the total catch. However, the practice of making several plantings on different dates, a few fish at a time, permitted more individual anglers to share in the catch. Although 4,500 legal-sized trout were planted each year, about half of the fishing trips were unsuccessful. Limiting the daily catch to 5 trout, instead of 15, did very little to reduce the percentage of unsuccessful anglers. Further reduction to 2 fish per day lowered the unsuccessful fishing trips to 36 percent. Plantings of rainbow trout and brook trout gave much higher returns to the fishermen than did equal numbers of brown trout. Rainbow trout also survived over winter as well as did brown trout, although in both species the survival was less than 10 percent. Over-winter survival of brook trout was less than 3 percent. Fin-clipped trout were recovered by fishermen more readily than those which were jaw-tagged. This difference was especially apparent during the first week following planting. Rainbow trout and brook trout, planted when water temperatures were below 50°F., exhibited an immediate downstream movement. Fish planted when water temperatures were above 50°F. showed very little movement. Legal-sized brook, brown, and rainbow trout, planted in a stream subjected to heavy fishing pressure, contributed to the catch for a relatively short time. Brook trout were exploited most readily; only 4 percent of the recoveries were taken after 40 days of liberty. For brown trout and rainbow trout these values were 26 percent and 22 percent, respectively. Planting large numbers of hatchery fish (up to 431 trout per mile) apparently had no effect upon the catch of wild fish in the stream. Although the catch per hour of the planted trout increased greatly at the time of planting, the corresponding weekly data on catch-per-hour of the wild trout showed no similar increase.