Salmon Hybrids May Hold Promise for Commercial, Sports Fisheries
KAMILCHE, Wash. (AP) _ What do you get when you cross a chum salmon with a chinook salmon?
That’s not a lead-in to a joke, but it is a fish story.
For Jim Seeb, research fisheries biologist at the University of Washington, and Tim Tynan, fisheries biologist for the Squaxin Island Indian tribe, the answer could revamp a big part of the fishing industry.
They are trying to develop a good-eating, high-quality salmon that can be raised in commercial fish-farming net pens economically.
″We’re looking for the best of both species,″ said Tynan. ″Our goal is to get a chinook-like fish that will require very little time in fresh water.″
Seeb, who has been working on crossing salmon from the five species found in the Northwest - chinook, coho, chum, pink, and sockeye - said his best results so far have been with the female chum and the male chinook.
″They have the salt water characteristics of the chum salmon, which is extremely useful,″ said Seeb, whose work is being done at the Zoology Department at Washington State University in Pullman.
The salmon crosses, which are sterile, also appear to have intermediate characteristics, including flesh quality and color, of both species, Seeb said.
The resulting fish - perhaps a ″chumook″ - would combine high-quality flesh of the chinook with the abilities of chum to adapt quickly from fresh to salt water. The latter would be a big economic advantage for pen-raised fish, since fresh water handling is relatively expensive.
A chinook spends about a year in fresh water before smoltification occurs, allowing the fish to enter salt water. That is six times longer than the chum needs.
The sterility of the hybrid salmon - a ″triploid″ since it combines two sets of female chromosomes with one male set - is a further advantage since its energy is spent growing rather than on maturing sexually.
Seeb’s work on hybrids also might have implications for sport fishermen.
He said coho female crossed with chinook male appeared a viable hybrid, and could produce ″a robust, sterile fish″ lacking the migratory instincts of native and hatchery raised salmon.
Thus the resulting salmon cross could provide a good fighting fish for local areas.
Bill Hopley, assessment and development officer with the state Department of Fisheries, which provides Seeb with eggs for his experiments, said the department was interested in his work, but only as an outside party.
If some promising hybrids were developed, he said, much work would remain to determine whether they would be beneficial for the department’s commercial and sports programs.
Seeb said his work on a sport fish was on the back burner at the moment, while he concentrates on an ideal pen salmon.
However, he noted a brown trout-brook trout hybrid, dubbed a ″tiger″ trout, is planted in some Midwest streams.
Financial advantages for a chum-chinook cross, if successful, are obvious, Tynan said.
He said fresh water hatchery operations in south Puget Sound, where the Squaxin tribe is located, are expensive because of required pumping operations.
In salt water, ″you just put them in the water (in pens made of nets) and the tide does the rest.″
And financial rewards provided by hybrid salmon could be great, Seeb said.
″The chinook salmon sperm is virtually free,″ he said. ″If we can use these salmon eggs that are free, and fertilize these (chum) eggs that are of little value, then I can see all kinds of potential.″
He said that if a fisherman could sell a chinook for $1.50 a pound, and a chum brought perhaps 50 cents a pound, ″conceivablely, we could turn a 50- cent-a-pound fish into a dollar-a-pound fish with little effort.″
Seeb, a graduate student from the University of Washington’s School of Fisheries, has raised some of the chum-chinook crosses to fingerling size in salt water aquariums at the school.
He cautioned that due to lack of space, his work has not had a chance to grow to where the results are proven. ″These are all potentials. We haven’t raised any to market yet,″ he said.
With the net pens of the Squaxin tribe, however, Seeb and Tynan hope to combine their separate ambitions - providing Seeb a place to test his hybrid work and giving the tribe with a new type of fish for its growing aquaculture interests.
The tribe has 53 net pens in operation now, some of them dedicated to raising pan-size coho that can bring $4 to $5 per pound at supermarkets around the country.
The tribe plans an additional 20 net pens to raise hybrids, more pan-size coho, Atlantic salmon and steelhead trout for a growing consumer market in quality fish.
End Adv Weekend Editions Aug. 30-31