JACKSON, Wyo. (AP) — Dead fish are used to kill lake trout embryos in an experimental method to combat a threat to a native Yellowstone Lake species.

The Jackson Hole News and Guide reports researchers successfully killed all the embryos in an experiment using hundreds of lake trout carcasses. Park managers are trying to help native cutthroat trout stage a comeback that could help reduce the number of elk calves eaten by grizzly bears. Yellowstone Fisheries Supervisor Todd Koel introduced the carcass experiment.

The method could be used on a larger scale depending on its success. Chris Guy of the Montana Cooperative Fishery Research Unit says fungus from the dead fish may be what killed 100 percent of the embryos in the experiment. Researchers are also trying to track where lake trout spawn.