Egg&Smolt® 3.3

U.S. Salmon Digest
Volume 3, Issue 3
May/June 1993

Special Issue:
Domsea® Coho A Domesticated Livestock!


"Twenty years from now fish farming will have evolved into a more predictable livelihood, less susceptible to the spasms of disease and environment".
Stephen Newman, Ph.D. Northern Aquaculture, Jan/Feb. 1993.


This issue of Egg&Smolt: U.S. Salmon Digest is based on an E&S interview with Dr. Robert Iwamoto, NMFS and Mr. Greg Hudson, Broodstock Manager for Domsea Broodstock, Inc.

Bob Iwamoto: has worked with the Domsea genetics program since its initiation in 1977. He was instrumental in the development of the selective breeding program and in 1985 he became Domsea's geneticist and Manager of RA&D.

Greg Hudson: started working with the Domesa Farms in 1976 and became its general manager in 1988. Hudson participated in the development of the selective breeding program. He is currently the general manager for Domsea Broodstock, Inc. and is in charge of husbandry, management and the genetics program.

The greatest aspiration of most salmon farmers is to develop a designer fish that is hardier and better adapted to netpen environments than its predecessors. With better growth performance and with genes that express traits which protect them from environmental hazards, these fish are more resistant to diseases. To create such a designer fish, its desirable qualities must be enhanced through inherent selective breeding programs. This in turn enables quality, cost contained production and assists in meeting the increasing world demand for seafood.

One of the pioneering selective breeding programs for salmonids is the Domsea genetic program for coho in Washington state. In an article written for Aquaculture Magazine, Douglas Tave summarized the programs success: "Perhaps the biggest benefit of this program is the development of a prototype selective breeding program that not only yields improvements in important production traits, but also demonstrates that such a program can complement, not complicate, husbandry and production efforts at a commercial aquaculture facility."

Described as 'classical quantitative genetics' by Dr. Robert Iwamoto, Domsea's genetic program was initiated in 1977. The company decided the quality and quantity of its production needed to be improved if it was to become a successful and prosperous operation. Consequently it was essential that Domsea control the entire life cycle of the coho. To depend on erratic returns of wild coho to the hatcheries makes it difficult to develop long-term plans.

Domsea's History
Domsea Farms, Inc. was founded in 1969 by Union Carbide and managed by Jon Lindbergh. At that point it was a saltwater netpen operation rearing pan-sized coho in Manchester, Washington. Later a selective breeding operation was added at Gorst, Washington. In 1979 Domsea Farms, Inc. was sold to Campbell Soup and in 1988 Global Aqua, a group of farmers from the West Coast of Norway, purchased the saltwater operation and hatcheries in Washington to set up an Atlantic salmon operation. Campbell Soup retained the Domsea coho genetic program and it's broodstock.

Following this sale Campbell Soup transitioned its operations to Idaho and Domsea's Puget Sound sites were gradually shut down. The pan-sized coho rearing operation was moved to Blind Canyon Hatchery, Idaho, under the direction of John Hewitt . From here the coho were staged to contract growers. Domsea's selective broodstock was transferred to Scattercreek Hatchery, near Rochester, Washington.

In July 1991 Domsea Broodstock, Inc.(DBI) purchased the Domsea coho broodstock and production from Campbell Soup. In June 1991, DBI,Inc. trademarked and registered the Domsea broodstock in the U.S. and foreign countries. DBI is owned by AquaSeed Corporation and Arnie Einmo of Dory Seafood, a joint venture which strengthened both the future genetic development and the marketing of coho foodfish. AquaSeed Corporation is an international supplier of salmonid seedstock. Einmo, who has built the Washington-based Dory Seafood, is a major marketer in the seafood industry and works with coho contract growers in four states.

The advantage of the Washington-based DBI purchase of the broodstock is that both the genetic and production programs are retained in the state. The program is maintained at a site leased from Swecker Salmon Farms in Rochester, Washington.

Domsea's Genetic Program
Dr. Bob Iwamato managed the Domsea's genetic program since its outset in 1977, initially as a graduate student and in 1985 as Domsea's geneticist and Manager for R&D. In an interview with Egg&Smolt, Dr. Iwamoto recalls his first contact with Domsea Farms, Inc.: "During my studies at the University, Domsea's Jon Lindbergh approached the fisheries department regarding feasibility studies for a coho breeding program. They were interested in identifying specific traits that would be of most economical value for their coho."

In a collaborative effort between the University of Washington School of Fisheries and the Washington Sea Grant Program, Domsea's genetic program was conceived. The University and Dr. William Hershberger, Principal Investigator, were funded to provide technical assistance to Domsea's breeding project. The primary goal of the program was to create and maintain a domesticated broodstock capable of rapid growth and good survival in intensive culture conditions. The methods outlined to support the goal included: a) establishment of brood lines based on family units, b) identifying selection criteria and genetic traits, c) developing an index to rank families, d) identifying cross schemes to minimize inbreeding, and, e) implementing the selective breeding program.

Domsea's research team identified three general characteristics necessary for a successful genetic program: fresh water growth, saltwater growth, and smoltification or survival rate of the fish upon transfer to saltwater. One major problem with coho farms was the high mortality rate, which could reach 40% when an abrupt method of saltwater transfer was applied.

In December of 1977, under the leadership of Jon Lindbergh and the research team, the first families of the genetic program were selected and established. Using a random or representative sample of the coho, the first crosses between selected male and female coho were initiated and two 2-year cycles were started: the 1977 odd-year line, and the 1978 even-year line. At the completion of one full cycle, the research team had achieved the desired results to further pursue the genetic program.

Domestication and Selective Breeding
In light of this success, a selective breeding program for the coho was designed. The program utilized "between family selection with individual selection at the time of spawning," according to Dr. Iwamoto. A family is defined as the progeny of the cross between a male and female coho with selection depending on performance of the family in fresh water, saltwater and smoltification. 20 males and 40 females were initially used crossing 1 male with 2 females to strengthen heritability estimates.

Ongoing data was collected on fecundity (gamete production) fertilization rates, survival rates to the eyed stage, in the hatchery and during the swim-up phases. Additional growth data was collected monthly on each family during the 5-month freshwater phase. The coho were then branded and transferred to saltwater. Three months later the pan-sized coho were inventoried to determine growth rate and smoltification survival rates. A selection index was used to rank families and identify the top families to be used as parents for the next generation of coho.

The process of selection and culling (rejection due to facility constraints and/or poor fertilization rates) at the various stages of the life of the salmon was repeated for several generations. Greg Hudson, Domsea's and currently DBI's Manager, recalls: "There were large gains in the growth of the selective fish when compared to the wild coho control right from the start. The gap became even more noticeable in the mid 80's. The selected fish have always grown faster and each year's growth would outdo the previous year".

Data indicates that after 4 generations of selective breeding the average growth increase per generation was approximately 6.7% in the fresh water phase and 10.1% in the saltwater phase. As a result the time needed to produce a marketable fish decreased Nebraska Domsea® coho growers are able to produce pan-sized coho (350 grams) in an eight month period, while in Washington, due to colder waters, pan-size coho are produced in 10 months. Coho families not used in the selection process were used as production broodstock in other hatcheries (Scatter Creek and Black River hatcheries in Washington). Since these coho came from a breeding program, their growth was better than coho grown for market and consequently improved the growth rate of the production coho.

Year Round Supply
One of the main goals of Domsea's genetic program in the mid 80's, according to Hudson, was "to have a year round supply of eggs so that we could stage the fish out to saltwater for pan-size grow-out and harvest every month of the year. This strategy would supply coho to restaurants and customers year round." Domsea's genetic team decided to take the first step in that direction by attempting to produce a second coho spawn. The team experimented for almost 7 years. "We played with a lot of ideas that did not work. Through a long process of trial and error we finally came upon the current method which lead us to the most successful results" said Hudson. "The success of the program makes Domsea coho the only broodstock to spawn at six month intervals".

Marketing
The eggs currently produced by the Domsea broodstock are, for the first time, available to customers and coho farmers around the world. Under Domsea's old management the company's policy was to retain the eggs and brood for in-house grow-out and production operations. Today, approximately 5-8 million Domsea eggs are sold to farmers in the U.S. and several other countries such as Chile, Japan, and Israel. DBI works jointly with AquaSeed Corporation and Dory Seafood. The main goal of the DBI operation is to continue the genetic program, spawn the broodstock, secure and ship the eggs to customers and salmon farmers worldwide. DBI, through AquaSeed Corporation, provides Domsea coho eggs to contract growers and Dory Seafood buys back the finished product.

Advantages of Farmed Broodstock
When asked about the advantage of farmed coho, Hudson explains: "Our farmed coho is a domesticated livestock like a broiler chicken. Domesticated coho are less stressed by the hatchery environment, more friendly and more willing to feed on a regular basis, which translates into faster growth rates than its wild counterpart. The result is a better and more affordable product for both farmers and consumers. Additionally, "...with selective breeding we can gage production to customer needs. We can work better with customer on timelines, specific traits, size, weight. However with wild coho, you take what you get".

Health Issues
When it comes to health issues, domestication and isolation have the added advantage of better disease control. Unlike saltwater pens, well-water fish farms are not generally exposed to severe cases of bacteria and viruses. At this isolation facility the coho is maintained in individual tanks and monitored closely. Well-water pumped into the tanks is relatively pathogen-free. In addition fish farms abide by numerous regulatory standards issued by such agencies as the EPA and FDA. "Between the Food and Drug Administration and the Department of Ecology," reports Hudson, "fish farms are regulated quite stringently, and much more so than the poultry or dairy industries." Levels of antibiotics or other chemicals that are allowable in the poultry or dairy industry are not permitted in farmed fish.

Domsea Coho; what's next?
Dr. Iwamoto was asked about what the future can hold for Domsea coho. He explains: "In addition to reaching a growth plateau, future goals for the Domsea coho include: maximizing the fecundity and hatchery performance of Domsea coho to increase the number and survival rate of the eggs." Another goal is to increase the egg size. Farmers prefer larger eggs due to the misconception that the resulting progeny's growth and survivability will be greater. Data indicates, however, that Domsea® coho stock grows faster and the resulting end product is 30-40% larger (see table 2). DBI is however, focusing some of its selection efforts on egg size to increase marketability.