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I I I I I I I I I I I I I I I I I I I Luteinizing hormone releasing hormone (LHRH) will replace HCG in 1998. The new injection protocol will involve injecting females on 2 consecutive days and males on 1 day. All spawning is done by paired matings with careful records kept of the male and female used to produce each family lot. When fish are ready to spawn, milt from individual males is stripped into graduated cylinders. Sperm extender (Gorman and Tiersch 1997) is added to double the volume of milt. Ifnecessary, viable sperm can be held for several days using this methodology. Eggs are stripped from the females into plastic food-storage bags and milt is added to the bag (Carmichael et al. 1996). A small amount of water is added after gametes are mixed. Volume is increased after about 30 seconds to water harden the eggs. The fertilized eggs are then transported to the hatchery where they are acclimated to the new water temperature and placed in separate tanks according to family lot. The eggs hatch 3 to 5 days later. 24 ROAD HATCHERY In late 1995, remodeling began on an existing warehouse, donated by the Bureau of Reclamation, located at 1149 24 Road, Grand Junction Colorado. By April 1996 the facility was complete and ready for operation. The 24 Road Hatchery is an intensive fish culture facility with a water re- use system. At full capacity 14,225 gallons of water are circulated through the system. The hatchery uses domestic water purchased from Ute Water Conservancy District. About 1,000 gallons of water are replaced every day. The facility (Figures 2,3) consists of30 4-ft-diameter and 6 8-ft-diameter circular fiberglass tanks. The 4 ft tanks have a 200 gallon capacity and the 8 ft tanks have a 940 gallon capacity. As a water reuse facility, the same water is reused over and over again, and therefore must be reconditioned each time it circulates (circulation rate is variable depending upon fish load). To recondition the water, harmful elements (e.g. ammonia, carbon dioxide, suspended solids, and harmful pathogens) must be removed. To do this, a series of filters and mechanisms are in place (Figure 3). First, a packed column, located inside the surge tank:, is used to strip carbon dioxide from the used water and re-oxygenate it. Then the water is filtered through a bag filter which removes debris larger than 3 mm. The water is filtered through the Bio:filter, which removes suspended solids and converts toxic ammonia (fish waste) into non-toxic nitrates that the fish can tolerate. The filter acts as a collection site for fish waste and excess feed, and removes them from the system. The most important function of the :filter is to convert toxic ammonia and nitrite to non-toxic nitrate. Two types of bacteria exist inside of the filter heterotrophic bacteria which breakdown and decay organic sludge and remove dissolved organics, and nitrifying bacteria which convert toxic ammonia and nitrite to nitrate. After the Biofilter the water passes through the UV-filter. The UV-filter bathes the water with -4-