BENTON — Rick Lawrence didn’t know what to expect before last year’s first alewife harvest from the Sebasticook River.

He predicted the town might make $5,000 on the fish harvest. It ended up generating $19,108 in new revenue for the town.

It was the year’s largest alewife run in the United States, with 452,000 fish harvested from May to June.

Following that landmark achievement, what’s expected for the coming year?

“There are a number of factors that make it a mystery — what kind of success we might have in any one year,” Lawrence said. “My hope is this is going to be a sustainable alewife run in the Sebasticook basin and it’s only going to get better as they improve passage upstream. I’m hoping it’s a dependable revenue stream for the town.”

Recently, Benton selectmen gave Lawrence a Spirit of America Foundation award for his “hours of research, management and leadership that resulted in a very successful first year for the town’s alewife harvest.”

As warden, Lawrence acquired the needed documentation for the creation of a new alewife access road, while coordinating the harvest with all the involved partners, which includes the state Department of Marine Resources.

“As a result of his tireless work, the town will reap substantial profits for many years to come from this historic fishery,” according to a note from selectmen in the 2010 town report.

Though Lawrence said he appreciates the town’s thanks, he also recognizes that last year’s harvest, and future ones, are unpredictable.

Benton’s first alewife harvest was made possible by the controversial removal of the Fort Halifax Dam in Winslow in 2008. The removal enabled the fish to continue upstream to Benton.

Alewives were abundant through New England and along the Atlantic seaboard and a “major food source,” before dams built during the Industrial Revolution in Maine and elsewhere blocked their access to the lakes and ponds where they spawn, Lawrence said. Now, only Maine and South Carolina harvest alewife, he said.

Alewives are a fascinating fish that take an amazing journey, Lawrence said. They are food for many predators — small-mouth bass, eagles, otters — as they swim downstream and into the ocean. And those that survive will return to the river four years later to spawn upstream, laying hundreds of thousands of eggs, before returning to the sea.

Last year’s harvest happened to coincide with that end of the four-year cycle, Lawrence said, meaning the alewives were babies that had left the Sebasticook watershed in 2005. The result was an estimated 1.5 million alewives passing through, using fish lifts at the Burnham and Benton Falls and dams. Alewives travel as far as north as Stetson Pond near Newport — 107 miles from the sea, Lawrence said.

The town contracted with Ron Weeks of Jefferson, whose crew netted the alewives, loaded them into large crates and sold them as bait fish.

Lawrence said this year’s alewife harvest will probably start around the first week of May, but it depends on factors such as water temperature.

Plans still call for the harvest to occur at the Benton dam, but there is now also the option of harvesting at a new site a mile downstream. The town purchased the land and built a road and parking lot — an area that can also be used for water recreation, Lawrence noted.

“It’s done and it’s in great shape, and we may or may not use it,” he said.

Lawrence said he’s pleased the town has taken the “innovative” step of helping the alewife population to rebound, while also reaping the benefits.

“I wanted to see this get going, and I’d be very happy to pass it to someone else,” he said.