The sky is ringed with ospreys. A quick downbeat, a flutter, and one of the fish hawks plunges into the silvery mass of tiny fish below it. From around the perimeter of the fish run children tug at their parents' sleeves and cry "Look! Look!" as the bird snatches a single fish from the pool. Deftly the osprey rearranges its catch, head forward, and swings out onto the Great Salt Bay to bring its prize to its young.

It is spring and the alewives have returned. Each year these fish swim in from the Atlantic to the streams in which they were born, where they will once again lay their eggs, ensuring the birth of the next generation. In the village of Damariscotta Mills in midcoast Maine, people, ospreys, seagulls, and bald eagles turn out each May to greet the elegant little fish as they pass through the Great Salt Bay, travel up the fish run that lies over the old mill dam, and into Damariscotta Lake to spawn.

The tiny alewives are an anadromous fish (from the Greek, meaning "up-running"), part of the herring family, Clupeidae. They hatch in freshwater, then promptly move into saltwater to grow and mature. They return to freshwater, often the very river or pond in which they were born, to spawn. In addition to the alewife, other anadromous fish native to the Gulf of Maine include Atlantic salmon, rainbow smelt, blueback herring, American shad, Atlantic sturgeon, and the shortnose sturgeon.

Unlike Atlantic herring, alewives (Alosa pseudoharengus) have a pronounced saw-edge on their underside. They are deeper-bodied than a true herring, and more fleshy than their freshwater cousins in the Great Lakes. Growing to approximately 6 inches in length (150 mm), alewife are related to menhaden, shad, and pilchard. They reach sexual maturity at three to four years of age. Unlike salmon, they do not die after spawning but return to the sea. In the course of its life, an alewife may visit its home stream three or four times to spawn.

The source of the name, "Alewife," has given scholars of language a good deal of trouble. Some say that alewife is a corruption of an Indian word, "aloofe," which meant bony fish. Others think that it was an English reference to a female keeper of an alehouse or tavern. A volume printed in 1675, made reference to by John Hay in his book, The Run, said: "The alewife is like a herrin' , but it has a bigger bellie, therefore called an alewife." And sure enough, an alewife does have a deep body and is sturdily-built forward, perhaps a reference to the stout female tavern keepers of merry old England! The term, alewife, is not used at all in Canada, rather the fish is called "gaspereau." Several rivers in New Brunswick and Nova Scotia bear the same name.

However they are known, all alewives head to the shores of the Gulf of Maine in the early days of spring. Research indicates that when the temperature of the water flowing from mainland rivers into the sea is warmer than the saltwater temperature, the alewives begin to move toward their home streams.

The fish may first straggle up a stream in tens or twenties for a few days. Then suddenly, as if a great door had been swung open, thousands upon thousands of 12-inch silvery fish are thrashing their way up estuaries, under bridges, and up streams or fish ladders to reach the ponds in which they were born.

For approximately one month the fish will continue to make their run. By June 15 the great migration will be over. The fertilized eggs will mature quickly in the warm pond water, generally hatching within a month. By mid-July until the early fall, juvenile alewives will slip downstream, retracing their parents' path from the freshwater sections of rivers to the sea.

Although formerly smoked and pickled as a food fish, most alewives are now harvested for bait for the lobster fishery. They still provide an important source of food for many fresh and estuarine fish, as well as the ever-present eagles, osprey, and other birds circling the rivers each spring. In the 1970s, the alewife was the most valuable commercial anadromous fishery in Maine with commercial harvests exceeding 3.4 million pounds annually. The harvests took a nose-dive in the 1980s, dropping to just 500 bushels in 1988. Today, landings are less than one million pounds. The drop was the result of a mix of environmental and economic factors: fish were blocked from returning to their spawning grounds by dams or other man-made obstructions, and the demand for alewife as a food disappeared.

Towns along the Gulf of Maine shoreline are re-discovering this seasonal ritual of the sea. Nearly 30 coastal Maine towns now exercise alewife fishing privileges on the smaller rivers and streams of the state. In Damariscotta, local people raised funds to restore the decaying fish run in 1998. And every May, as they have for decades, the residents of Damariscotta Mills gather for a gala pot-luck picnic near the fish run, where they celebrate this small fish and its whisper of summer to come.