7203 - Laserfiche WebLink

Home Browse Search

1 each pond. Subsample s of stocked Colorado squawfish (n = 100) were held in live-cages in each pond for 62 hr after stocking to quantify stress- related mortality that may have resulted from hauling and stocking; all of ' these fish survived through the holding period and were subsequently released. To measure growth and body condition, samples of fish were measured and weighed at the time of stocking and once monthly thereafter from 1986 through 1988 (except during winter months when ice-up prevented seining) to monitor growth and body condition. Condition was calculated using Fulton's coefficient of condition: K = W x 105/L3, where W is weight (g), L is total length (mm) and 105 is a factor to bring the value of K near unity (Tesch 1971). When fish were captured, 10-20 individuals were preserved in 10% buffered formalin for later analyses. In the lab, digestive tracts of preserved fish were dissected and food r i id f tems enti ied and counted; endoparasites were also counted and lengths of individuals of a representative sample were measured. Dissolved oxygen, temperature, conductivity, and clarity of the ponds were measured biweekly throughout the year. More detailed analyses of water chemistry were performed once during summer, fall, and winter 1986 and spring 1987 by Grand Junction Laboratories, a certified testing company. In addition to the fish from Willow Beach NFH, a small group of Colorado squawfish was obtained from Jackson NFH, Wyoming. Researchers there had completed their laboratory investigations of these fish and made available f or our use those that remained. These fish had originally been provided to the Jackson facility as swim-up fry by Dexter NFH. The fish were air- 5