In this May 31, 2005, file photo, volunteers load a bushel of alewives onto a lobsterman’s truck in Nobleboro, Maine. Scientists with the Atlantic States Marine Fisheries Commission say they are starting to see upward trends in the populations of alewives, also known as river herring. (AP Photo/Robert F. Bukaty, File)

PORTLAND (AP) — A little fish on the East Coast that once provided vital protein for American colonists and bait for generations of New England lobstermen is slowly making a comeback after falling victim to lost habitat and environmental degradation.

River herring once appeared headed to the endangered species list, but they’re now starting to turn up in rivers and streams at a rate that fishing regulators say is encouraging. The fish is a critical piece of the ecosystem in the eastern states, where it serves as food for birds and larger fish.

In this June 4, 2005, file photo, alewives make their way up the Damariscotta Mills fishway, in Nobleboro, Maine. Alewives, also known as river herring, once appeared headed to the endangered species list, but the little fish appear to be slowly coming back in the rivers and streams of the East Coast. (AP Photo/Robert F. Bukaty, File)

The comeback is most noticeable in Maine, the state with by far the largest river herring fishery in the country. Maine fishermen capture alewives, a species of river herring, and their catch of nearly 1.7 million pounds last year was the second largest in the last 37 years.

“The stocks in Maine in the last three years have rocketed up,” said state Rep. Jeffrey Pierce, a Republican lawmaker and the head of the Alewife Harvesters of Maine. “Years ago, we couldn’t have predicted.”

The herring spend most of their lives at sea, returning to freshwater to spawn in the spring. The fish’s populations dramatically fell after generations of damming, habitat loss and overfishing. The federal government considered adding the fish to the endangered list before deciding against it in 2013.

Fishing for river herring was one of the earlier industries in colonial America, and annual catches of more than 50 million pounds were common up through the 1960s. Those numbers fell to about 1 million pounds per year in the mid-1990s, causing commercial catch to plummet through the 2000s.

But a 2017 assessment of 54 river herring stocks found that 16 experienced trends of increasing abundance and only two showed a declining trend, said Tina Berger, a spokeswoman for the Atlantic States Marine Fisheries Commission. Others were either stable, showed no trends or didn’t produce enough data, she said.

“While abundance in these river systems are still at low levels, dam removals and improvements to fish passage have had a positive impact on run returns,” she said.

While river herring are not as commonly used as food for humans as they were centuries ago, they remain fished commercially as a source of bait. Maine has fewer than 20 commercial river herring fishermen, who fish for alewives in rivers every spring, sometimes using gear that is more than a century old.

The fish are entrenched in the culture of coastal Maine, where the town of Nobleboro retains an ancient law that widows can apply for two bushels of alewives.

The fish’s comeback, and the slight uptick in catch, has spurred calls for conservative management from environmental groups, which have long advocated for removal of dams to help bring back the river herring population.

The federal government’s consideration of adding river herring to the endangered species list was spurred by the Natural Resources Defense Council in 2011. Brad Sewell, who oversees fisheries work for the council, said warming waters off New England remain an “extinction event waiting to happen” for this fish.

“It’s concerning to me that people, and to some degree government officials, are trumpeting this limited success in Maine as being indicative of what’s going on with river herring coast-wide,” he said. “That’s simply not the case.”