Abstracts of Fisheries Management Reports, Technical Circulars
and Project Reports of the Fisheries Branch

Daiva O. Zaldokas & Debra L. Aird

B.C. Fisheries Branch, 2204 Main Mall, U.B.C.,
Vancouver, B.C. V6T 1Z4

Fisheries Technical Circular No. 91


LIRETTE, M,G.  1988.  Telemetric Studies of Summer and Winter 
Steelhead in the Stamp and Somass Rivers, 1984-85.  Fish. Rep. No. VI 

The freshwater migration behaviour of summer- and winter-run steelhead 
(Salmo gairdneri) were studied on the Somass River system between 
August, 1984 and May, 1985.  Radio telemetry techniques were employed 
to monitor instream movements of steelhead and to determine time and 
location of spawning.  Between August 21, 1984 and March 19, 1985, 271 
steelhead were captured by angling the Stamp and Somass Rivers.  Fifty-
nine fish were held for broodstock, thirty-three were radio tagged, one 
hundred and sixty five were anchor tagged, six (8%) summer-run and 8 
(4%) winter-run steelhead died from angling injuries.  Tagged fish were 
comprised of summer-(n = 70), early winter- (n = 94) and late winter-run 
(n = 34) steelhead.  Thirty-two tagged steelhead (16.2%) were recovered at 
Robertson Creek Hatchery.  Seventeen tagged fish were recaptured by 
sport anglers.  Angling recaptures varied between summer (7.5%), early 
winter (10.8%) and late winter (3.4%) tag groups.  Wild steelhead were 
recaptured at over two times the rate of hatchery produced fish.  One of 
the ten steelhead radio tagged in August (10%), five of the seven tagged in 
October (71%), seven of the eleven tagged in December (64%), and five of 
the five radio tagged in January/March (100%) were monitored to their 
spawning location. The average migration rate varied between radio and 
anchor-tagged groups of summer- (0.24 and 0.77 km/week), early winter- 
(0.42 and 1.12 km/week) and late winter- (0.64 and 2.44 km/week, 
respectively), run steelhead.  Summer- and winter-run hatchery produced 
steelhead utilized the smolt release site (7-9 kms) and Roberston Creek 
Hatchery 25-27 kms) for spawning.  Wild winter-run steelhead utilized 
areas above and below Stamp River falls for spawning (9-11 and 19-21 
kms).  The spawning location of wild summer-run steelhead was not