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AGFD began stocking rainbow trout below the dam in 1964. They introduced aquatic food organisms, amphipods commonly called scuds (Gammarus so.), in 1968 to provide forage in the newly created tailwater. By 1977 trout over 3.5 pounds were frequently being harvested and trophies over 10 pounds were taken regularly. The large fish gained national notoriety for Lees Ferry. Angling pressure increased dramatically as the media spread the word about this new trout fishery. Increased angling pressure decreased average fish size and total numbers in the river. AGFD responded to the increase in angling pressure by reducing the limit from 10 to 4 fish, restricting fishing method to artificial lures only and requiring immediate kill or release of any fish taken. Despite these restrictive regulations, average size of fish caught continued to decline. Fluctuations in water level associated with hydroelectric peaking power caused concerns among anglers about stranding of spawning fish and eggs, impacts to the food base, and angler access. These concerns were incorporated into the Glen Canyon Environmental Studies (GCES), however, high flows and spills from 1983-1986 confounded evaluation of the impacts of fluctuating flows. Between 1980-1984, anglers voiced increasing concern over the decline in the fishery, in particular the declining size of fish. During this time, angler pressure had increased five times the level experienced in 1917. In 1990 a slot limit protecting all fish between 16-22 inches was incorporated and the limit was decreased to two fish. The slot limit increased trout biomass at the same time that phase II of GCES called for low river flows that dried portions of the river bed and reduced the trout food supply. Trout were stressed by the reduction of the food base and infestation by a common nematode resulting in decline in physical condition. Trout either became thin or died of starvation as the nematode interfered with digestion. The amount of water and flow regime released from the dam was demonstrated to have an impact on the Lees Ferry trout fishery. As the discharge increased and daily fluctuations were restricted, a more abundant food base developed. The skinny fish were eliminated by harvest or natural causes and the fishery is once again healthy and robust. IV. FISH MANAGEMENT PLANNING Within Glen Canyon NRA, each of the different habitat types (flowing rivers, inflows, Lake Powell, Lees Ferry tailwater and streams) favors a different complement of fish species (Table 1). In this section of the FMP, habitat types within the recreation area are described, along with the status of fisheries in each area. Management goals that conform to each of the various sets of habitat and species are presented, then management objectives are identified to achieve the goal. 14