Alaska eliminates invasive pike and restocks lake with 6,836 Arctic char

In a remote corner of Southcentral Alaska, state biologists carried out a dramatic restoration: they treated an entire lake with rotenone, a plant-derived piscicide, to wipe out an invasive population of northern pike. After the treatment, post-surveys confirmed the pike were gone. The next step was rebuilding what had been lost. In June 2013, the Alaska Department of Fish and Game (ADF&G) stocked 6,836 hatchery-reared Arctic char fingerlings into the now pike-free lake, jump-starting the recovery of a native fishery that had been pushed out by the predator. This account draws on ADF&G’s technical reports and project summaries documenting the rotenone treatment and restocking. Read on to know more:Why northern pike are a problem in AlaskaNorthern pike are not native to most of Southcentral Alaska. They were illegally introduced into several lakes in the mid-20th century and have since spread through connected waterways, especially as warming temperatures and changing hydrology make it easier for them to move and survive. As apex predators, pike eat large quantities of native fish, including salmon, trout, grayling and char. In some lakes, they have all but replaced native s...