Federal hatchery raises a mountain of trout

The Fish Site
by The Fish Site
16 April 2007, at 1:00am

US - In Arkansas, they coddle a lot of trout. In one federal hatchery alone, 1.3 million, or 500,000 pounds, of trout are reared each year.

Situated below the humongous dam at Norfork Lake in the Ozark Mountains, the Norfork National Fishery Hatchery boasts some other big numbers and features.

The main configuration is a straight field of 96 raceways, each a couple of feet wide and some 30 feet long. The raceways, where young trout swim, are infused with 24,000 gallons of water a minute - which comes at that speed from 100 feet below the surface of Norfork Lake.

On the top of the hill overlooking the net of raceways are two aerator buildings. The cold lake water (44 F.) is gravity fed into the aerators and the oxygen-rich flow slides down massive outdoor pipes - like those used to transport oil across desert fields. The rejuvenated water is what the young trout rely on.

And there is more. In the main building are indoor incubation tanks - at least I’d call them that. Tiny fish are put into long rectangular spas and allowed to grow to about two or three inches before being thrown in the foremost flume at the tender age of four months.

But the weird science show is actually in another room, the egg hatchery room.

In a darkened space, three giant, glowing jars sit by a cold wall above a moist cement floor. In each two-foot high ewer is a swirling mass of eggs, like some kind of living lava lamp. The eggs are orange, like old-fashioned creamsicles, and if you bend down close to the glass, you see the individual living pellets.

But the awe of a miracle doesn’t stop there. Inside every viable egg are two black dots - each half the size of a pepper flake. The dots are the embryos’ eyes.

All at once, you realize thousands of eyes are looking at your glass-distorted face. The mind boggles at the thought of how all this unformed life might be reacting.

After showing me around the more visited features, Kenneth W. Boyles, the manager of the U.S. Fish and Wildlife Service Hatchery at Mountain Home, takes me up to the aerator buildings. Even before he completely opens the door to the larger of the two, the noise is overwhelming. It’s the unmistakable sound of rushing water, but overgrown like a giant waterfall, like the sound heard at the bottom of Niagara Falls. Strange, too, because as Boyles tells me, there are no generating motors in the aerator buildings. Electricity is not part of the process. A series of large vertical pipes are cut with open bottoms and the water foams in powerful torrents to huge drains across the grated floor. Put together the open pipes look like the exhaust of a powerful rocket, except it’s not fire being emitted, but water. In this process, ox ygen is added and the cold, reinfused water serves the system’s growing trout.

Source: The Mercury