The Pennsylvania Fish and Boat commission will continue to transition away from producing brook trout in its hatcheries, and the agency intends to steer cooperative hatcheries in the same direction.
According to the draft version of the Strategic Plan for Management of Trout Fisheries, the agency intends to cease distribution of brook trout fingerlings to 40 cooperative nurseries located within watersheds where wild brook trout are present. Between 2020 and 2022, the PFBC will no longer stock brook trout in watersheds where the wild variety exists, and by 2024 all remaining brook trout production will utilize triploid, or sterile, fish.
Those hatcheries previously receiving brook trout fingerlings will be given rainbow and/or brown trout instead. At PFBC hatcheries, brook trout production will be reduced but no reduction in the total number of fish raised at those facilities is planned. Production of rainbow, golden rainbow and brown trout will be increased to replace brook trout.
The move will help stop the spread of gill lice in wild trout populations and protect the genetic integrity of those fish, according to Kris Kuhn, director of the PFBC’s Bureau of Fisheries.
“We’ve been transitioning to less brook trout for some time. In the early 2000s we began to receive angler reports of low opening day catches, and the brook trout were the most likely to leave a stocking location,” he said. “We found a better return with rainbows than brook trout.”
The gill lice issue is more recent than concerns over trout movement, and the parasite has been found in some populations of wild brook trout in the state. Kuhn said gill lice aren’t spread from trout coming out of state hatcheries as those facilities are certified to be free of the external parasite.
However, stocking hatchery brook trout in a watershed where the wild variety exists could hasten the spread of gill lice. Kuhn said there are two types of gill lice in Pennsylvania and they are species specific. One affects brook trout and the other impacts rainbows.
“In watersheds with wild trout populations that are infected with gill lice, we don’t want to increase the potential vectors to spread it throughout the watershed,” he said. “By not stocking brook trout in these areas, our goal is to eliminate another host for gill lice.”
Currently, the PFBC stocks about 68 percent rainbow trout, 21 percent brown trout, and 11 percent brook trout. Cooperative nurseries, which the PFBC partners with and provides fingerling trout to grow into adults for stocking the following year, stocks an additional one million trout each year into Pennsylvania waters. Currently, cooperative nurseries stock about 55 percent rainbow trout, 33 percent brown trout, and 12 percent brook trout.
According to the plan, the agency seeks to cease distribution of brook trout fingerlings to all cooperative nurseries by 2024. The proposal to not only drastically cut brook trout production at hatcheries but switch to raising sterile brook trout will also occur over the next four years.
Agency hatcheries are already raising some sterile brook trout, Kuhn said, from eggs that were received from other states. Producing sterile brook trout in-house is something that needs to be explored, he added.
Sterile brook trout are reared from eggs that have been exposed to heat and pressure, and it can be a labor intensive process.
“There’s an initial investment in the equipment needed to do that. Is it worth our investment to do that here? The jury is still out,” Kuhn said.
Still, the reduction in brook trout being raised and stocked from PFBC hatcheries and cooperative nurseries isn’t something that Kuhn believes anglers will notice. Most anglers are just happy to catch fish, he said, and rainbows and browns suffice for angler enjoyment.
“I don’t anticipate a lot of pushback on this,” Kuhn said. “The state hatchery-raised brook trout isn’t our state fish, it’s the wild brook trout and that’s what will benefit from this.”
