dam. At the present time, the hatchery is rearing 

 catchable size rainbow trout for stocking the reser- 

 voir. In addition, there is a limited number of cut- 

 throat trout on hand which will be used for brood 

 stock as a source of eggs for future stocking pro- 

 grams. In addition to these, it is expected that 

 this hatchery will also supply kokanee salmon for 

 the reservoir. 



The first year's operation of the Dworshak 

 hatchery started with the collection of eggs from 

 trout transported to the hatchery from the trap at 

 the dam site during the period of October 1968-May 

 1969. The fish reared in the untreated water for 2 yr 

 from the 1969 brood year were released in the 

 spring of 1971. At the same time, the 1970 brood 

 year fish reared in the controlled environment of the 

 reuse system were also released. The controlled 

 environment of the reuse system made it possible to 

 rear fish to migrating size ( 17 cm) in 1 yr instead of 

 the 2-yr growing period that is required when the 

 untreated water is used. 



DISEASE CONTROL 



In 1968, the federal government of the United 

 States imposed regulations requiring that salmonid 

 fish and eggs imported into the country be free of 

 whirling disease, caused by the protozoan 

 Myxosoma cerehralis, and viral hemmorrhagic sep- 

 ticemia. The regulation is intended to protect the 

 nation's fishery resources from fuilher introduction 

 of these two fish diseases. It may also serve as a 

 model for adoption by other countries similarly 

 concerned about protecting their own resources. 

 This regulation is included in Title 50, Code of Fed- 

 eral Regulations. 



Increased traffic in fish and eggs has spread the 

 virus disease, infectious pancreatic necrosis, in 10 

 yr from the nonheastem section of the country into 

 the trout and salmon producing areas of the West. 



The detection of this virus cannot be accom- 

 plished by border inspections: consequently, control 

 had to be effected at the originating hatchery. Sev- 

 eral states now require that eggs or fish entering the 

 state be accompanied by a certificate of health. But 

 separate actions by the states can only be partially 

 successful, and to effect a coordinated nation-wide 

 program, federal legislation has been introduced in 

 the Congress. If passed, the bill will regulate the 

 interstate and foreign commerce of fish for pur- 

 poses of disease control. 



FISH TRANSPORTATION 



Fish hatcheries in the United States utilize many 

 diversified types of distribution equipment from 

 40-liter cans to elaborate tanks equipped with aera- 

 tion devices and oxygen equipment. However, 

 most hatcheries today generally use truck mounted 

 distribution tanks. Hauling capacity is governed by 

 volume of water in the tanks, design of tank, aux- 

 iliary equipment used, and size and species offish 

 being hauled. Various materials such as wood, 

 plywood, fiber glass, steel, and aluminum are used 

 for construction of tanks. Fiber glass-plywood 

 tanks are becoming very popular because of such 

 advantages as lightweight, low cost, good insula- 

 tion, and strength. Insulated units, having recir- 

 culating water systems and an o.xygen supply, can 

 be used to haul loads in ratios (unit weights offish 

 to equal unit weight of water) of 1.1:5 for trout and 

 1.2:4 for channel catfish, Maloy (1966). 



There are reports of varying degrees of success in 

 increasing hauling ratios by use of sedative drugs 

 and buffer agents. Phillips and Brockway (1954) 

 found that starvation of fish before shipment and 

 the maintaining of low water temperatures were 

 more effective than the addition of chemicals. 



Ma.xwell and Thoesen (1965) reported on the 

 successful hauling of large quantities of rainbow 

 trout and largemouth bass fingerlings by airplanes 

 equipped with water tanks. Sealed plastic contain- 

 ers, 2 mil and thicker — packed in insulated outer 

 cartons, partially filled with water, and inflated with 

 oxygen — are used successfully by many hatcheries 

 for surface and air transportation of fish. A typical 

 shipment is 50,(K)0 bass fry in 3.8 liters of water for 

 a period of 48 hr. 



A recent development in the field of fish trans- 

 portation is the "Tish pump." The fish pump is a 

 modified fruit pump which was initially used to 

 transfer vegetables, fruit, dead fish, and seafood. 

 The pump is especially designed to eliminate sharp 

 edges in the pump body and to allow unobstructed 

 passage of water and produce. The water serves as 

 a cushioning agent. 



The pump comes in two diameters. 12 and 15 cm. 

 The 12-cm size is used for fish up to 15 cm in length 

 and the 15-cm size handles fish up to 47 cm in length. 

 The California Department of Fish and Ciame tested 

 this pump and found that 900 kg of trout could be 

 loaded into a tank truck in 6 min with slight loss of 

 time due to crowding racks. Other tests indicate that 



