AUGUSTA — Brown trout populations have been declining along the Kennebec River in recent years — but they could soon be replaced by a more unusual species: bolt action rifles.

On Sunday, a father and son were fishing on the river, near the northern end of Canal Street in Augusta, when they reeled up a rusty, Remington Model 700. The weapon had a scope on top, a retractable bipod on bottom and three rounds in the magazine.

They brought their catch to local police, who are now trying to determine the rifle’s owner and the reason it was underwater in that part of the city.

“I am not able to tell for sure why it’s there, but it is possibly related to some type of burglary, theft or other crime,” Lt. Chris Read said in an email. “It’s illegal to duck hunt with a rifle, so the ‘oops it fell out of the boat’ doesn’t sound too good. You can’t hunt from that area within the compact urban zone with a rifle.”

After police received the rifle from the fishermen on Sunday afternoon, they verified that it wasn’t reported stolen, and they entered it into a database of recovered firearms maintained by the National Criminal Information Center, Read said.

While there were three rounds in the magazine of the rifle, Read said the action was so rusted that there wasn’t any risk of it firing.

“I don’t believe that anyone could have got a round into the chamber, making it not much more than a piece of steel,” he said.

Police have not determined the rifle’s age, Read said. More information wasn’t immediately available about what part of the river the men were fishing in.

Justin Gilbert, a licensed gun dealer who co-owns Lionguard Armory in Chelsea, looked at a photo of the rifle that was pulled from the river and said he thought it was probably made within the last 15 years. Its stock was plastic, rather than wood, Gilbert said.

Gilbert couldn’t recognize the brand of the scope or the bipod — which can extend to the ground to keep a rifle steady — but he said those add-ons gave the rifle the appearance of something that a marksman might use to shoot from a distance, rather than what most hunters would carry through the woods.

“On my hunting rifle, I wouldn’t put a bipod or tripod,” he said.

But, Gilbert added, those features could have been added to the gun by a teenager trying to mimic the appearance of a military or police sniper rifle.

The Model 700 has been around for decades. According to the Remington website, newer versions of the gun can cost between $700 and $1,500, based on a variety of customizable features.

“The legendary strength of its 3-rings-of-steel receiver paired with a hammer-forged barrel, combine to yield the most popular bolt-action rifle in history,” the company’s website declares. “Top choice of elite military snipers, the Model 700 is unequalled (sic) in tactical precision. Whether defending freedom or pursuing big game, its out-of-the-box accuracy is unmatched.”

Augusta police typically recover firearms “once or twice” every year and store them at the station, Read said. The current inventory include pistols, rifles and shotguns.

In recent years, Augusta city councilors have debated whether to sell or destroy firearms that have been recovered by police. They considered that question in 2015, and may do so again in the next month, said City Manager William Bridgeo.

That’s because the district attorney’s office is asking the city whether it wants to accept a shotgun that was forfeited to authorities following a drug bust in Augusta last summer, Bridgeo said.

“I guess it’s time to revisit the issue,” Bridgeo said. “Police are typically neutral on it, and it’s clearly a policy decision. Sometimes there’s some emotion that attaches itself to the issue. We’ll see, but it’s not a pressing issue. (The recovered gun inventory) takes up a closet in a large police station.”

Charles Eichacker — 621-5642

[email protected]

Twitter: @ceichacker