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Title: Protection of Wild Adult Steelhead in Idaho by Adipose Fin Removal: 1984-1985 Annual Report.

Technical Report ·
DOI:https://doi.org/10.2172/6333028· OSTI ID:6333028

All Idaho hatchery-reared steelhead released in the spring of 1985 received an adipose fin clip to differentiate between natural or wild and hatchery, fish, thus allowing for protection of wild fish in the sport harvest. Between 25 September and 14 December 1984, 6,360,542 steelhead trout (Salmo gairdneri) were marked by excising the adipose fin. A total of 10,336 man hours were required to complete the operation. Clip quality and healing, mortality, and adipose fin composition were determined. Quality checks indicated less than 1% of the fish had more than 25% of the fin remaining. Combined mortality at all three hatcheries was 0.3% of the total fish marked. Observed and in vivo test showed complete healing of the excision within 3-4 weeks (observed) and 22 days (in vivo). Bibliographies were compiled for fin regeneration, marked fish survival, hooking mortality, and related catch-and-release studies.

Research Organization:
Idaho Department of Fish and Game (IDFG)
Sponsoring Organization:
United States. Bonneville Power Administration.
DOE Contract Number:
AI79-84BP14903
OSTI ID:
6333028
Report Number(s):
DOE/BP-14903-1; ON: DE87010556
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English