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Relative Return to Creel of Triploid and Diploid Rainbow Trout Stocked in Eighteen Idaho Streams
Author(s) -
Dillon Jeff C.,
Schill Daniel J.,
Teuscher David M.
Publication year - 2000
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(2000)020<0001:rrtcot>2.0.co;2
Subject(s) - rainbow trout , hatchery , biology , stocking , fishery , trout , fishing , ploidy , fish <actinopterygii> , zoology , ecology , biochemistry , gene
s of fertile nonnative hatchery trout have led to interspecific and intraspecific hybridization of native salmonid stocks throughout North America. Use of sterile triploid hatchery trout in stream‐stocking programs could reduce genetic risks to native stocks while addressing public demand for consumptive fishing opportunity. Techniques to produce triploid salmonids are well developed, and triploid rainbow trout Oncorhynchus mykiss are readily available from commercial sources. However, there is no published information on the return to creel of triploid trout in stream recreational fisheries. We purchased mixed‐sex triploid and diploid rainbow trout eggs from a commercial supplier and reared the resulting fish to catchable size. Flow cytometry was used to verify triploid induction rates in the triploid group. Estimated cost to produce a triploid catchable rainbow trout was about 15% higher than for a diploid fish. We jaw‐tagged and stocked 300 triploid and 300 diploid fish into each of 18 streams throughout Idaho and used tag returns to assess relative return to creel and timing of returns for the two groups. In all, 1,849 tags were returned by anglers, 931 from triploid fish and 918 from diploid fish. Overall returns were not significantly different between groups (paired t‐test; P = 0.80). Mean time to harvest also did not differ between groups (paired t‐test; P = 0.35). These results suggest that triploid rainbow trout can provide stream angling opportunity equal to that provided by fertile diploid fish. Although there are other concerns regarding the stocking of hatchery trout in streams containing native trout, we suggest that using triploid rainbow trout in stream‐stocking programs can help balance the demands for both consumptive fishing opportunity and conservation of native stocks.