SIDNEY (AP) – A month-long Atlantic salmon fishing season opens on a portion of the Penobscot River near Bangor on Friday.

The “experimental” season, running from Sept. 15 to Oct. 15, will offer the first opportunity to fish for sea-run salmon in Maine rivers since 1999.

State officials hope the opening will boost public support for Maine’s salmon restoration efforts.

Nearly 100 fishermen had purchased licenses as of Monday evening. The number is expected to increase by the weekend, according to Patrick Keliher, executive director of the Maine Atlantic Salmon Commission.

Biologists said Tuesday that water temperatures in the Penobscot have been within acceptable ranges. The commission may close the fishery temporarily if the temperature reaches 68 degrees Fahrenheit to avoid over-stressing the fish.

In fact, the commission retains the right to close the fishery at any time.

Fly-fishing for salmon will only be allowed on a small stretch of the Penobscot beginning 150 feet below the Veazie dam and extending to the site of the former Bangor dam. Popular salmon pools just below the former dam site will not be open.

“Most of the traditional fishermen know these areas and these spots very well, but we will be on the river to let people know,” biologist Peter Ruksznis said.

Green flags at the Veazie Dam as well as the Veazie, Eddington and Penobscot salmon clubs will indicate the river is open to fishing. Red flags will mean salmon fishing is prohibited.

Anglers may only use single-pointed, barbless flies. All salmon must be immediately released unharmed without being removed from the water and any angler who catches a salmon is automatically done fishing for the day.

Ruksznis said fishermen will be required to record details of their outings and report them to the commission at the end of the season. Failure to report fishing activity could result in a fishermen being denied a license in the future, Ruksznis said.

“The ultimate success of this program is going to depend on the anglers down there policing themselves,” Keliher said.

Anglers must purchase a special Atlantic salmon license to participate in the fall fishery. Licenses, which are $15 for Maine residents plus a $2 processing fee, are available at many town offices or online at www.informe.org/moses.