Evaluation of stocked game fish in the Tanana Valley, 1994

Description

Gill nets and fyke nets were used to sample the populations of game fish age 1 and older in Birch, Quartz, and Chena lakes. The sample compositions for all lakes were 63% to 74% rainbow trout, 17% to 34% coho salmon, 6% Arctic grayling, and 2% to 3% Arctic char. The CPUE for rainbow trout was highest near-shore in Birch Lake and Chena Lake but highest off-shore in Quartz Lake. For coho salmon the highest CPUE was off-shore in Birch Lake and Quartz Lake but highest near-shore in Chena Lake. Arctic char, however, had the highest CPUE off-shore in all three lakes. The CPUE for Arctic grayling was highest off-shore in Birch Lake but highest near-shore in Chena Lake. Generally, the largest individuals of each species were captured in Quartz Lake. The size of the fish captured in Birch and Chena lakes were similar. Studies in 1993 and 1994, along with mail out surveys and historical data provided information to assess how well ADF&G was progressing toward achieving management objectives. In 1992, none of the management objectives were achieved and only two objectives were achieved in 1993. However, recent changes made to the stocking program are having an effect and progress was made towards achieving more objectives. The total cost of the stocking program decreased from about $605,000 in 1992 (a historic high), to about $512,000 in 1993, and to about $293,000 in 1994. The number of days fished for stocked game fish in 1992 (about 49,700) was the lowest since 1986, but, in 1993 the number of days fished increased to about 68,300. The cost-per-day of fishing decreased from a historical high of about $12 in 1992 to about $7.50 in 1993. From 1989 through 1992 the percent of the total annual stocking cost by location was highest for Harding Lake (42% to 68%) and by species was highest for Arctic char (43% to 61%). Since 1992 the percent of the total annual stocking costs for Harding Lake dropped to about 5% and stocking costs for Arctic char dropped to 25%. Most of the cost reduction in the stocking program was the result of reducing the number of Arctic char that were stocked. Small lakes now account for about 50% of total annual stocking costs by location and rainbow trout account for about 40% of the total annual stocking costs by species. In 1993 the small lakes accounted for the most number of days fished on populations of stocked game fish (about 22,500 or 33% of the total number of days fished). The percent return to the creel in Quartz and Chena lakes for rainbow trout was 4.9% and 23.4%, respectively. The cost-to-the-creel for rainbow trout stocked as fingerlings ranged from $0.35 to $1.47; subcatchables ranged from $0.63 to $4.61; and catchables ranged from $0.42 to $12.11. Usually only one size cohort was stocked in a lake and a different size cohort was stocked in each lake. Previous studies showed that the cost per survivor to a certain size or age was lowest for fish stocked as fingerlings in Quartz Lake, subcatchables stocked in Birch Lake, and catchables stocked in Chena Lake. Coho salmon stocked as fingerlings provided a 14.8% return in Birch Lake, a 21.0% return in Quartz Lake and an 8.0% return in Chena Lake. The cost-to-the-creel for coho salmon that were stocked as fingerlings in all three lakes were variable through time ($0.29 to $3.36) but cost-to-the-creel between lakes for the same year were usually similar.

Subjects

Genres

• Statistics

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