GREEN BAY, Wis. (AP) - Restoring fishing in the Fox River and the bay of Green Bay in the wake of PCB contamination could cost paper mills a minimum of $106 million, the U.S. Fish and Wildlife Service says.

When the dangers of the chemical PCB were identified in the 1970s, a consumption advisory was put on all recreationally caught fish.  The loss to anglers over the past two decades has been about $106 million, said David Allen, a natural resource damage assessment manager for the U.S. Fish and Wildlife Service.

The finding is one of several in a series of reports the federal agency has done to asses the damage for the river and the bay.

The purpose of the study is to determine how much in either money or restoration programs the paper companies should provide, Allen said.  Restoration programs could include stocking more fish, increasing the habitat where fish spawn, stopping other kinds of pollution that impact fish or building boat ramps or more facilities so there's more access to fishing, Allen said.  If the companies provide money, it would go toward those programs, Allen said.

The agency calculated anglers' losses in terms of dollars by surveying hundreds of fisherman living in eight counties bordering on or near the Fox River and bay of Green Bay about their fishing habits and preferences.  They were asked to rate the importance of higher catch rates, less stringent fish-consumption advisories and cheaper boat-ramp fees.

Sport anglers are due some type of compensation, whether it's habitat restoration, enhanced fish-stocking programs or something else, said Dick Hentz, vice president of the Green Bay chapter of Walleyes for Tomorrow.

"There's no question we have missed out because of the quality of the water we are fishing in," Hentz said.

The latest reports presented Monday at a public meeting in Green Bay also looked at  tumors found on walleyes' livers and ruled that they are "strongly associated with PCB exposure."

The report also studied lake trout, but found that their reproductive problems have been caused not by PCBs but by a thymine deficiency caused by the arrival of a foreign species, possibly alewives.

Paper companies widely used PCBs, or polychlorinated biphenyls, to make carbonless paper and other products until the chemical was outlawed in 1977.  PCBs have been linked to cancer, reproductive problems and poor mental development in children.

The U.S. Environmental Protection Agency wants PCB-contaminated silt to be removed from the river.  State and federal studies released in February outlined options for river cleanup that cost from $150 million to $728 million and include dredging, capping and natural recovery.

The EPA could decide to exercise its "Superfund" authority, which lets the agency force a cleanup and bill responsible parties.