By the first day of trout season, nearly 4 million fish will be stocked in state waterways for recreational use. Trout require very clean aquatic habitats to thrive, and Pennsylvania has many popular fishing areas that are unsuitable for trout most of the year. But according to Ken Undercoffer, of the conservation group Trout Unlimited, even raising trout in hatcheries can cause harm to wild populations.

"Hatcheries are built almost invariably at the headwaters of prime trout streams, because hatcheries require lots of clean, cold water," says Undercoffer. "But it's like any other large animal cultural facility. It contaminates that water, and then you have to put it somewhere and they put it back in the stream."

Undercoffer says because of this year's drought, the hatcheries were polluting a higher percentage of the water in trout streams, prompting the state to reduce its trout production.

Dick Snyder is chief of the fisheries division of the Fish and Boat Commission. He says it's hard to say what the impact will be of this year's smaller trout release. "We won't know the bottom line until into July when the bulk of the license selling period is passed," he says. "Some folks have indicated they may be less inclined to go fishing, knowing the numbers are down."

Snyder says if the Commission doesn't find the money to improve water filters at their fisheries, there may be a permanent reduction in the number of trout released in the state. Trout stocking is an important activity across much of Pennsylvania because relatively few areas of the state can support wild trout. Snyder says the Commission is especially careful not to disturb streams where trout are breeding naturally. "At the same time," he says, "We stock some 4,400 miles to provide the opportunity to go fishing."

Snyder says the ideal home for wild trout is in shaded mountain streams, where the temperature remains cool throughout the year. Trout are less likely to be found in developed areas of the state such as the Southeast and Southwest, which both rely heavily on annual trout releases.