9328

• UCREFRP Catalog Number: 9328
• Author: Miller, W. H.
• Title: Analysis of Salmon and Steelhead Supplementation.
• USFW Year: 1990.
• USFW - Doc Type: \
• Copyright Material: NO

adults BC concluded that if you have the habitat, parr are more cost effective over fry or
smolts.
- BC stocks steelhead fry for two primary reasons: colonization -defined as releasing
fry above anadromous barriers, and supplementation -stocking fry in underseeded
stream reaches.
From the 1987 brood year BC released 1.2 million; 2.0 g fry (200/lb) into 28 systems. A
typical release method is by helicopter to enhance dispersal. BC fry stocking began in
the early 1980s. Criteria used for survival of fry-to-smolt are largely dependent on:
1. age at smolting, 2. amount of physically suitable habitat for all life history stages,
3. size of fish released, 4. productivity of different streams, (i.e., total alkalinity can very
from 4 to 200 mg/1), and 5. presence of competitors or predators. Biologists we
interviewed stated that in the early fry programs they overstocked. They used no
prescribed stocking formula in these early programs and the results were disappointing.
BC biologists went back to streams, developed site specific biostandards for stocking
densities, and now release fish at more conservative stocking densities. Now they
consider total usable area rather than the older method of total wetted area. They -cite
many examples of overstocking resulting in decreases in growth performance of both
hatchery and wild juveniles. The results from the Coquihalla River are encouraging with
fry-to-adult survival ranging from 0.4 to 1.3 percent. Expected survival was estimated at
1.3 percent (Ptolemy 1986). They measured a fourfold increase in standing crop of
juveniles following the fry released.
Salmon
In release year 1988, -the Department of Fisheries and Oceans (DFO) recorded releases
of approximately 530 million pink, chum, coho, sockeye, and chinook salmon (Table 6).
DFO biologists use indigenous broodstock to ensure against stocking maladapted fish.
They release the progeny from wild fish into- the parent watershed after adipose clipping.
Broodstock are spawned (streamside) 1:1 male/female ratio and gametes taken to
hatcheries. Biologists verify carrying capacities of life stage to be stocked in terms of
usable habitat before outplanting progeny.
Chinook
In 1988, DFO released 63.6 million chinook salmon of various life stages. Production of
chinook salmon (stream and ocean types) for stocking is primarily through hatchery
operations (federal, provincial, and community economic development programs). These
hatcheries do not recycle broodstock. DFO biologists also develop groundwater side
channels with upwelling incubation for chinook production. These groundwater channels
also provide critical rearing habitat.
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