Shortly after 1956, a locked gate was installed in a rock crevice of Devils Hole to limit public access to the site. By 1970, as the shallow shelf was exposed by groundwater depletion, an artificial shelf was installed at Devils Hole. It was never used by the fish. In 2005, of sediment was removed from the shallow shelf to encourage feeding and spawning. While the number of larvae appeared to increase as a result, the population still experienced a net decline over the following year. In January 2006, biologists began supplementing the fish's food supply in response to observations of poor health and malnourishment. After vandalism resulted in the death of a pupfish in 2016, the National Park Service added additional barbed wire to the top of the fences surrounding Devils Hole, also installing more motion sensors and video cameras.