Fish Hatchery at Willow Beach

The sound of a sudden splash shattered the silence as a rainbow trout, trying vainly to shake loose the hook which held it captive, leaped high from the waters of upper Lake Mohave. It battled gamely in the tradition of its famous fighting species but was soon on the stringer of a proud fisherman. And thus did it fulfill its intended destiny which had begun many months before in the Willow Beach National Fish Hatchery.

This outstanding rainbow trout hatchery, which will be one of the largest producers in the federal system when it reaches full capacity, began operations in April, 1962. Willow Beach is in Black Canyon on upper Lake Mohave about eighteen miles south of Hoover Dam by automobile (including a paved, four mile side road from U. S. 93).

This area, which also includes a fine fishing and boating resort, was chosen as a hatchery site for two principal reasons: its accessibility and the canyon's ideal water temperature for trout an almost unvarying 55 degrees. This constancy is accounted for by the fact that water being released into Black Canyon from Hoover Dam is drawn from the lowest depths of Lake Mead.

An invitation to the public is extended by superintendent George Mapes to visit the hatchery and view its aquarium and rearing facilities first hand.

This is a tour you will certainly enjoy and perhaps will find even more interesting if we review the hatchery's activities before your visit.

To do this, let us go back to our fighting rainbow trout, which we had observed in its fruitless battle for freedom, and follow it through its previous months of life in the hatchery.

It first arrived at Willow Beach from another hatchery or commercial egg producer as a fertilized egg packed in moss and melting ice with perhaps a million companions. At this point they looked like small opalized pearls with a plainly visible dot in each. These dots are actually eyes which take from two to three weeks to develop after the eggs are fertilized.

Before reaching this "eyed stage" they are extremely delicate and cannot be shipped. A blow on the side of the trough or even a loud noise can literally kill them by the thousands.

However, when they have “eyed-up” and are durable enough for shipment they are purposely subjected to severe jolting. This “shock treatment” kills the weak and partially fertilized eggs, leaving only those with a much higher survival potential. After being received at Willow Beach our trout-tobe and his contemporaries were placed in their first hatchery homes; the incubator boxes. These simulate as closely as possible natural spawning areas.

However, despite the most diligent precautions many

PHOTOGRAPHS BY THE AUTHOR By Darwin Van Campen

However, despite the most diligent precautions many eggs will die before hatching. And, as a fungus develops almost immediately on the dead spawn, fishculturists must remove them constantly to prevent its spreading to the live eggs. When the eggs have absorbed a sufficient number of heat units the length of time depending upon the water temperature the tiny one-half inch trout hatch out. For about ten days each fish lives from the food in the yolk sac which forms a part of his body. During this period the sac diminishes and eventually forms the fish's belly. When our young rainbow and the others in his lot had sufficiently absorbed their yolk sacs they were transferred to troughs and began to receive food for the first time. The bill of fare consisting of small fish granules might have been a little monotonous to them at times but they certainly couldn't complain about the service which included a regular feeding every twenty minutes. After about two weeks in the trough when they had grown to a full inch, it was moving day again. Their new quarters, longer and deeper, were called tanks, and here they remained until they were about two months old and two inches long. Then came a big day in our little trout's life. He and his fellows were taken from the main hatchery building and placed in large outdoor raceways measuring eight feet wide and a hundred feet long. There are forty of these four feet deep structures at Willow Beach which are divided into two banks. The newcomers were kept in the upper bank for nearly three months until they had reached four inches in length. They spent their next two inch growing period (about forty days) in the lower set of raceways, and were then divided into two groups and held until they had become plantable trout eight to nine inches long.As they had grown larger their feeding rate was decreased to three times a day and their new diet consisted of pellet sized dry food and ground liver.

Frequently the growing fish were graded according to size and the larger ones removed. Trout are cannibalistic in their feeding habits, and the small fish would soon have been devoured if such precautions had not been taken.

The hatchery goal for plantable fish from each new group of eggs is seventy percent. To come even close to its attainment constant vigilance must be kept against the possibility of disease spreading through the heavily populated raceways. To guard against this a laboratory, staffed by two hatchery biologists, is maintained to diagnose and provide cures for such problems as they arise.

The hatchery's water supply (12,000 to 18,000 gallons per minute) comes directly from Lake Mohave. This means that its trout are raised in water having almost exactly the same characteristics as that into which they will be planted. This has proved extremely beneficial.

The growth rate of trout planted by the hatchery is amazingly high. An example of this is provided by a tagged trout that was only nine inches long when planted. Just thirteen months later when it was caught, it had grown to twenty-four inches and weighed over five pounds.

The hatchery is responsible for stocking Lake Mohave, the Colorado River from Needles to Davis Dam and the Colorado between Lees Ferry and Glen Canyon Dam. That it is doing an excellent job in all of these areas is readily evidenced by the full creels and happy smiles of fishermen who "never had it so good."

Two hundred and ten thousand pounds of trout, which is approximately one million fish, will be planted by the Willow Beach hatchery in 1964.

When the trout are ready to be planted they are forced into one end of the raceway with a screen and dipped out in nets to be weighed. They are then placed in the two thousand pound capacity fish distribution truck which plants them in the remote river locations by means of a large pipe that guides them safely into the water.

For lake stocking a specially constructed barge is used. After being filled by the truck it moves back and forth over the planting area releasing the trout through a gate.

One of these trout released somewhere in Lake Mohave's waters was the hero of our story, freed at last after ten months of hatchery life and ready for a destiny which would eventually pit his fighting spirit against a fisherman's pole.