The future of fishing at Utah's Strawberry Reservoir may depend on the activities of Marxist guerrillas in Peru, where a poison called rotenone is produced.

Biologists at the Utah Division of Wildlife Resources want to distribute 1.3 million pounds of powdered rotenone over the surface of the reservoir to kill all the fish life.The kill would eliminate non-game fish, which have been crowding out species preferred by anglers.

After the poison dissipates, the reservoir would be replanted with cutthroat trout, kokanee salmon and sterile rainbow trout, creating a "high-yield, fairly fast fishery," said Utah chief of fisheries Bruce Schmidt.

Strawberry, which would require from one quarter to one half of the world's annual production of rotenone, would be the largest lake in which such a poisoning project has ever been attempted.

The poisoning originally was scheduled this month, but had to be delayed for a year because of a shortage of rotenone. The treatment has been rescheduled for August 1989, but doubts remain about the supply and price of rotenone.

"I can't say right now" whether the rotenone will be available, said Bill Stetter, an agent for Foreign Domestic Chemicals. His New Jersey-based company markets most of the rotenone used in the world.

"The Strawberry project is my No. 1 priority," he said.

The reasons for the shortage can be traced to Peru, which produces almost all of the world's supply of the poison. Rotenone is a naturally occurring chemical, the majority of which is extracted from the roots of the cube plant (pronounced "koo-bay") which grows in the country's mountains.

Stetter said terrorist activities of guerrillas have disrupted agriculture in many rural areas of Peru and substantially reduced the cultivation of cube plants.

The rotenone shortage has been aggravated further by Peru's faltering economy as well as unusually rainy weather, which has washed out access roads to the farming areas where cube is grown.

"The last harvest was not good," Stetter said, and it's too early to predict the size of this year's crop.

The success of the 1988 harvest is critical to Utah fishermen, Schmidt said, because a new and much larger dam has been built at Strawberry and the reservoir is slowly increasing in size.

Strawberry Reservoir is projected to have a surface area of 13,300 acres by next August. Schmidt said that is the largest area which can be successfully treated. If the poison isn't available in 1989, the reservoir will grow too large for treatment.

When full, Strawberry Reservoir will have a surface area of 17,163 acres, according to the Bureau of Reclamation.