Author
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Wolters, William |
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Submitted to: Aquaculture America Conference
Publication Type: Abstract Only Publication Acceptance Date: 11/15/2004 Publication Date: 1/15/2005 Citation: Wolters, W.R. 2005. Early growth evaluation of five selected atlantic salmon stocks for inclusion in a north american breeding program. (abstract).Aquaculture America Conference. p. 496. Interpretive Summary: Technical Abstract: Atlantic salmon aquaculture is one of the most successful global aquaculture enterprises, and has wide acceptance as a main food item by American consumers. The Northeastern U.S., and particularly the state of Maine, has the ideal location and unique opportunity to further increase salmon production and be the leader in cold-water marine finfish aquaculture. However, problems and regulations on environmental issues, mandatory stocking of 100 percent native North American salmon (in an effort to protect populations of federally endangered wild Atlantic salmon), and disease have seriously impacted economic viability of the U.S. salmon industry. In response to these problems, the Agricultural Research Service (ARS) is developing a breeding program utilizing North American stocks at the National Cold Water Marine Aquaculture Center (NCWMAC) in Orono and Franklin, Maine. In the first year of the breeding program, individual families and pooled family groups were obtained from two St. John’s River sources, Penobscot River, Gaspe' (all-female and triploid all-female), and landlocked salmon stocks. Eyed eggs from fall 2003 spawns were obtained from commercial, federal, and state hatcheries, disinfected upon arrival, and incubated in separate hatching jars. At approximately 30 days after initiation of feeding, fish densities were equalized to 250 fish/tank, fed 5% of the tank’s total biomass in 3-4 daily feedings and evaluated for growth over a 30-day period. Because not all eggs hatched nor began feeding at the same time, growth was calculated using the thermal-unit growth coefficient formula: TGC = [(W2 ' - W1 ')/T x D)] x 1000; where W2 is the final weight (grams), W1 is the initial weight (grams), T is the temperature (Celsius), and D is the number of days between measurements. Significant differences were found between stocks for growth (p<0.01). Thermal growth coefficients (mean+SE) for Penobscot, both St. John’s river, Gaspe, and landlocked stocks were 5.7+.03, 6.6+.03, 6.9+.04, 8.0+.06, and 8.1+.07, respectively. Smolts will be stocked into sea cages in the spring of 2005 and evaluated for growth and sexual maturity under commercial culture situations. Following performance evaluations in sea cages, a selected group of fish will be retained and spawned at 4-years of age. |
