Supersalmon

The broad-beamed chinook salmon were coming home from the sea. Seattle's Lake Union swarmed with the far-ranging voyagers, and when the advance guard struggled up a fish ladder on the campus of the University of Washington, they got an unusually warm reception. Waiting to greet them was Professor (of Fisheries) Lauren R. Donaldson, their breeder, nurse and public relations man. For these were no ordinary salmon. Conceived on the campus, they were the third generation of college-bred chinooks, selected for vigor, meatiness and quick maturing. Dr. Donaldson hopes to develop them into a race of supersalmon that will forage in the northeast Pacific like high-bred beef cattle on the Nebraska sand hills.

Real Mess. Dr. Donaldson has been improving fish for 31 years. Starting with rainbow trout, a salmon relative, he bred ponderous super-rainbows that weighed 6 lbs. when only one year old, 500 times the weight of ordinary yearling rainbows. He still raises some of these juvenile giants and gives them to the state department of fisheries for secret release in lakes near Seattle. Then he drives out in the early morning to watch the fun. "All of a sudden," he says, "someone will yell like hell when he ties into one of these monsters. Fishing rods get broken, and as the word spreads, residents complain about the cars parked all over. It's a real mess."

Salmon are harder to breed than Donaldson's trout. Instead of spending all their lives in fresh water, where they can be fattened like hogs, ocean salmon come to fresh-water streams only to lay their eggs. When the fingerlings are three inches long, they take off for the sea, where they get most of their growth. They come home to deposit their eggs and sperm with unerring accuracy in the stream where they were hatched.

Donaldson began his salmon improvement program in 1948 with fertilized eggs from chinook salmon that run up Soos Creek, well south of Seattle. He hatched the eggs in tanks on the campus and nursed the infant salmon until they grew into fingerlings. Then he washed them down a sluice into Lake Union, and they swam out into the Pacific. After four years, the college-bred salmon returned to the campus full grown, like old grads gathering for a class reunion.

Hereditary Vigor. Each succeeding year Donaldson has graduated groups of fingerling salmon, identifying their class by clipping their belly fins. In 1955 came a startling break; 48 of the fingerlings released in 1952 came back from the ocean full grown. This was revolutionary; chinook salmon normally take four years to reach maturity. Donaldson selected spawn from the best of the 48, nursed the hatchlings into fingerlings and launched them into the sea. The fast-growing trait proved permanent; in 1958 a startling proportion of the class of '55 returned full grown to the hatchery. They were as big or bigger than ordinary chinooks, and their quick growth had saved them from a full year of ocean hazards. Only about 0.1% of ordinary chinook fingerlings survive to return to their birthplace. In Donaldson's class of '53, 3.25% eventually came home.

Donaldson selected the best fish that returned in 1958, and raised 260,000 fingerlings from their eggs. It is these fish that are now beginning to come home. When they splash up the concrete ladder into a big, new holding tank, Donaldson and assistants will treat them unsentimentally. The best of the females will be split open and their eggs mixed with sperm milked from the best males. The fertilized eggs will be incubated, and when the pedigreed fishlings hatch, they will be fed on the ground-up bodies of their parents.

Dr. Donaldson expects to release 250,000 superfingerlings early next spring when Puget Sound is rich in natural fish food. When the class of '62 comes back to the campus in three years, they should be better salmon than their parents. But Donaldson hopes to improve them even more. "Give us another ten or 20 years," says he, "and you'll see salmon like you never saw before."

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