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. . JULY 1986 . FEASIBILITY OF A SQUAWFISH FACILITY AT THE COLORADO-UTE POWERPLANT AT CRAIG, COLORADO Tom Mandis and Neal Ward The location of a hatchery and rearing facility at this site h~s both possibilities and problems. Most of the ponds would be unsuitable 'ijue to chemical contamination. An old water treatment plant and pond are available but they are considerable distance from any hot water. They probably should not be considered in the early planning stages. The vacant construction buildings close to the plant offer the best option to start with. They could easily hold six circular tanks (8-ft diam) and four 40-ft portable raceways (see diagrams). Having all the fish inside the buildings would offer several advantages: 1. Security 2. Better disease control 3. Better control over water quality 4. Better control over the fish Being wild fish, there will be some of the squawfish that grow faster than others due to the fact that they are more aggressive. It is when you have a large variation in size that cannibi1ism becomes a serious problem. By having the fish inside you could keep then sorted as to size and cut down on this considerably. It would be a good idea to have three or four small circular tanks to raise the fish in from hatch to swim-up. It is during this 3-6 day * time period that bunching occurs and a lot of the fish smother. I believe a circular tank with a slight current would help alleviate this problem. Starting the swim-up fish on feed will have to be examined. At Dexter NFH and Willow Beach in the past they have been put into tanks or ponds with plankton. This may be difficult at the Craig location. There are feeds on the market that the fish should accept. Also, they ha~e had some success starting them on brine shrimp (Roger Hammond, pers. comm.). Basic Criteria For Rearing Squawfish: l. Water temperatures -- This seems to be more important than photoperiod f9r spawning. Temperatures around 70-72 F are ideal. /This unit will have water to 75 if necessary. 2. Water quality -- It is known that squawfish have tolerated low oxygen levels for a length of time. As with any fish though, the less stress put on them, the better they will do. The water at this unit will be both heated and pumped at high pressure. These conditions are conducive to low oxygens and high nitrogen gas. We will have to be prepared with aerators and packed columns to combat this if necessary. Should try to keep oxygen levels at 6 ppm or above.