Branford, Conn. — In a bay near this coastal town, the sea was boiling with hundreds of herring-size shiners leaping to flee a marauding squad of bluefish. “These waters are coming back,” Bren Smith yelled above the shrieking din, as sea gulls plunged near our boat, scooping up fish. Mr. Smith grows seaweed and shellfish in Long Island Sound, and he says he’s seen a lot more action out here recently.

What thrilled me about this scene was that I was witnessing what happens when fishery managers set strict catch limits to stop overfishing.

Those leaping silvery fish were menhaden, also known as bunker, or pogies. To Mr. Smith and other fishermen I spoke to, there are encouraging signs that the menhaden population along the Atlantic Coast is healthy after decades of intensive commercial exploitation. Other sea creatures whose lives are intertwined with them also seem to be doing well. Sharks, whales, bluefish, tuna, osprey and other predators depend in part on these fish.

“There’s all this life that wasn’t there before,” John McMurray, who captains his own charter boat, told me. He said it’s been a boon for his sports fishing business off Long Island: “In the past four years, striped bass fishing has gotten a lot better, bluefish as well. We’re even getting bluefin tuna coming inshore to feed on the schools of menhaden.”