1a. Objectives (from AD-416)
1: Define phenotypic measures and estimate genetic and phenotypic parameters for commercially important traits such as growth, cold tolerance, fillet color, and fat content in Atlantic salmon. • 1A. Define phenotypic measures and estimate genetic parameters for growth (carcass weight), fillet color, and fillet fat content in Atlantic salmon. • 1B. Define phenotypic measures and estimate genetic parameters for cold tolerance in Atlantic salmon. 2: Develop a multi-trait selection index to produce and release Atlantic salmon germplasm selected for multiple traits.
1b. Approach (from AD-416)
The research program supports the coldwater aquaculture industry with a breeding program developing improved lines of North American Atlantic salmon. Atlantic salmon cultured in research objectives in the breeding program is based on life stage and separation of year classes. An incubation system will be used for eggs and newly hatched fry before first feeding, parr tanks are used for first feeding fry to 30-40 g salmon, smolt tanks are for 30-40 g to 100 g pit tagged salmon, on-grow tanks are for 100 g to 1.0 kg salmon in their second year, 3-yr old broodstock tanks are for 1.0 kg to 3.0 kg salmon, and one 4-yr old broodstock tank is for growing salmon to 3.0 kg to 6.0 kg until spawning. Up to 224 families of Atlantic salmon with 300-500 eggs/family will be cultured each year. Approximately 250 eggs will be saved from each family mating and raised through parr size. Typically 30-40 smolts per family will be saved as nucleus of fish for the breeding program and cultured in biosecure tanks will become broodfish. Additional 30-40 smolts per family will be cultured and transferred to an industry collaborator for stocking into net pens for performance evaluations. Net pen fish will be cultured to market size, harvested from sea cages, and transported to a commercial processing plant. Data will be collected for carcass weight, sex, and stage of sexual maturity. Muscle tissue samples will be collected from each fish for fat and pigment analyses. A separate group of fish from each family will be pit tagged as smolts, cultured to 2-year old sub-marketable size and stocked into replicated fish culture tanks equipped filled with filtered, UV-treated seawater in a recirculation biofilter system. The water temperature will be lowered approximately 1C per day using a glycol-based chiller system capable of chilling seawater temperatures down to approximately -2C. Individual fish will be scored on the basis of temperature and time to loss of equilibrium and death and survival. Data will be analyzed to calculate phenotypic and genetic variation for carcass weight, fillet color, fillet fat, and cold tolerance traits. Heritabilities, breeding values, and genetic correlations for carcass weight, fillet fat, fillet color, and temperature tolerance obtained from performance data will be used to develop a selection index or index of merit for each individual broodfish chosen for spawning in a selected line. Selection of 4 year old fish for spawning will occur when fish are moved from 3-yr old broodstock tanks into the 4-yr brood stock system prior to the spawning season. Relative economic weights for each trait will be determined in consultation with industry collaborators and account for the market value of each trait. Germplasm from an Atlantic salmon line selected for multiple traits will be released to commercial producers and consumers.
3. Progress Report
Pedigreed families were produced by spawning broodstock selected for improved carcass weight from the 2005 year class of salmon already in the NCWMAC breeding program. Fish from the 2005 year class had been cultured in marine net pens in collaboration with industry, and growth data were analyzed to obtain estimated breeding values on broodfish to be spawned as a line selected for increased carcass weight. The mean carcass weight for 2005 year class St. John’s stock fish from the NCWMAC breeding program was 4.87 kg compared to a mean carcass weight of 3.94 kg for industry fish cultured under the same conditions. NCWMAC fish were 24% larger than industry fish and 70% larger than wild Penobscot River fish (2.88 kg) used as a control line. Data was used to calculate breeding values on captive sibling adult broodfish and a line of St. John’s River fish was selected for carcass weight and spawned in the fall of 2009. Breeding values of female (N=123) brood fish ranged from -57 to +913 g (mean=444) and male (N=66) breeding values ranged from +147 to +913 g (mean=606). A total of 122 viable families were produced with mean breeding value of +527 g (+0.48 SD from the population mean) for this select population. Eyed eggs were disinfected and incubated in separate hatching jars or trays. Fry were transferred to separate rearing tanks prior to first feeding and are being raised to parr size. When the fish reach 20-40 grams, individual fish will be pit tagged and cultured communally before being stocked into sea cages for performance evaluations and some fish will also be exposed to superchill temperatures for evaluation of cold tolerance.
1. Atlantic salmon selected for increased growth and weight. Commercial salmon producers in the U.S. predominantly utilize stocks that are not many generations removed from wild, unselected stocks, and are legally required to culture certified stocks of North American salmon. Scientists at the National Cold Water Marine Aquaculture Center in Franklin, ME evaluated the growth of salmon from their breeding program in commercial sea cages in collaboration with industry. A salmon line selected for increased growth or weight was produced and germplasm was released to commercial production. Utilization of improved germplasm will increase the profitability and sustainability of coldwater marine aquaculture in the U.S. and provide a quality seafood product to U.S. consumers.
2. Arctic charr selected for increased growth. Arctic charr have a flavor many consumers feel is superior to trout and salmon, and interest in charr aquaculture is increasing with the growing trend of producing seafood grown in sustainable production systems, however, expansion of arctic charr culture has not been rapid because of many production problems. Scientists at the National Cold Water Marine Aquaculture Center in Franklin, ME evaluated the growth of two different arctic charr stocks for culture in recirculating aquaculture systems. Development of a breeding program for US arctic charr stocks could alleviate some of the production problems limiting expansion of arctic charr culture and provide a source of germplasm with improved production traits, and a charr line selected for fast growth and delayed sexual maturity will be released for cooperative research evaluations and commercial production in the fall of 2009.
3. Developing sustainable commercial feeds for Atlantic salmon. Sustainable aquafeeds for Atlantic salmon (Salmo salar) are being developed by scientists at the National Cold Water Marine Aquaculture Center in Franklin, ME using plant-protein concentrates in collaboration with the University of Idaho (UI) on a marine aquaculture research grant funded by NOAA. Two alternative soybean and wheat protein sources were evaluated for use in juvenile Atlantic salmon diets. Atlantic salmon had lower growth and had to consume more of the plant protein diets in order to achieve the same growth when fed a typical fish meal feed. Data from these trials have been requested by a commercial feed company for consideration of these ingredients in commercial salmon diets.
4. Atlantic salmon germplasm selected for increased growth transferred to the Maine Aquaculture Association (MAA) for commercial distribution. The objective of the cooperative research project is to facilitate technology transfer from the NCWMAC Atlantic salmon breeding program to industry stakeholders. The NCWMAC transferred approximately 500,000 eggs from the USDA ARS National Cold Water Marine Aquaculture Center’s Atlantic salmon breeding program to the Maine Aquaculture Association. The germplasm originated from St. John’s River stock and was named “USDA NCWMAC 2009 Year Class Atlantic Salmon Select Line”. The MAA distributed the disease certified North American salmon germplasm to private industry under the direction of its stakeholder committee. Utilization of the improved germplasm will increase the profitability and sustainability of coldwater marine aquaculture in the U.S. and provide a quality seafood product to U.S. consumers.
5. Atlantic salmon genetics and breeding research with Atlantic Salmon of Maine (ASM) LLC. This research project develops and facilitates research collaboration with an industry partner conducting evaluations of salmon germplasm from the USDA breeding program under commercial culture conditions. A meeting was held to discuss yearly research objectives in salmon breeding and discuss plans for germplasm evaluation. The NCWMAC provided ASM with salmon smolts from two different sources. ASM is culturing the salmon to marketable size using standard Atlantic salmon culture methods in a marine environment. ASM will harvest the salmon when they reach marketable size, transport them to a processing plant, and NCWMAC scientists will collect data on carcass weight, stage of sexual maturity, and survival. The data will be used in the NCWMAC salmon breeding program to develop and ultimately release new lines of Atlantic salmon. Utilization of the improved germplasm will increase the profitability and sustainability of coldwater marine aquaculture in the U.S. and provide a quality seafood product to U.S. consumers.
6. Atlantic salmon genetics and breeding research with Cobscook Bay Salmon (CBS). This cooperative research project was initiated to develop research collaboration with an industry partner that will conduct evaluations of salmon germplasm from the NCWMAC breeding program under experimental conditions at commercial land-based facilities. ARS scientist at the National Cold Water Marine Aquaculture Center in Franklin, ME provided CBS with salmon smolts from different families from the St. John’s River stock. CBS stocked the fish into replicate culture tanks and will feed experimental diets formulated with plant proteins replacing fish meal and grow the salmon to 1-2 kg size. NCWMAC scientists will collect data on weight gain and feed conversion on the different diets and determine family and diet variation on growth. Utilization of the improved germplasm will increase the profitability and sustainability of coldwater marine aquaculture in the U.S. and data from these trials have been requested by a commercial feed company for consideration of these ingredients in commercial salmon diets.
7. Atlantic salmon genetics and breeding research with Phoenix Salmon US (PS). This cooperative research project was initiated to develop research collaboration with an industry partner that could provide eyed eggs from experimental families of Atlantic salmon from fish in the breeding program that had been evaluated and cultured to broodstock in commercial net pens. The NCWMAC and PS held a meeting to discuss the results of the annual growth trial of salmon from the NCWMAC breeding program. Phoenix Salmon agreed to provide some eggs from their industry pool for evaluation in the NCWMAC breeding program. These fish will be included in the commercial evaluations. NCWMAC scientists will provide data to PS which broodfish are spawned. Utilization of the improved germplasm will increase the profitability and sustainability of coldwater marine aquaculture in the U.S. and provide a quality seafood product to U.S. consumers.
Wolters, W.R., Barrows, F., Burr, G.S., Hardy, R.W. 2009. Growth Parameter of Wild and Selected Strains of Atlantic Salmon (Salmo salar) on Two Experimental Diets. Aquaculture. 297:136-140.