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A Look Back

Article By 
Ron Wilson

North Dakota Game and Fish Department fisheries staff first chemically renovated lakes of unwanted fish species in 1950.

Following successful treatment on selected small waters, the renovation program took off on a large scale in 1951, according to reports from more than a half-century ago.

“Evidence … collected proves that the lake rehabilitation program has been extremely valuable in the overall fisheries management program. For this reason, lake and stream eradication will again resume on a large scale …” reported Dale Henegar, then Game and Fish Department fisheries chief, in North Dakota OUTDOORS in 1956.

Henegar said Department fisheries staff at the time used two chemicals, toxaphene and rotenone, for renovation projects. Rotenone remains the go-to chemical for rehabilitating lakes in North Dakota today.

The black-and-white photo accompanying this piece was taken in 1960 or 1961. It features Robert Needham, a graduate student at Montana State College and native of Steele, North Dakota.


The focus of Needham’s graduate work was on the effects of toxaphene on plankton and aquatic invertebrates in five North Dakota lakes, two of which were located in the Turtle Mountains where this photo was likely taken.

“The use of toxicants in fisheries management has provided considerable information concerning the effects of various poisons on fish. Much less is known of the effects on the fish food organisms,” wrote Needham in his graduate thesis, a copy of which is stored at Game and Fish Department headquarters in Bismarck.

“The object of the present day study,” Needham continued, “was to determine the effects of low toxaphene concentrations on the plankton and certain other aquatic organisms under natural and controlled conditions. This was made possible by the rough fish removal program in North Dakota, during which various concentrations of toxaphene were used.”

It is believed the hand pump in the photo was used to draw water samples from different depths. Some of the other gear used during research, such as a metal device used to collect “plant inhibiting organisms,” was designed by Needham.

Much has changed since Needham presented his graduate thesis in 1962. For one, toxaphene, which was also used as an insecticide in parts of the country, was eventually banned in the United States for all uses.