T HOUSANDS and thousands of little black sail-like objects were leaving the sea and heading into Holiday Stream. They looked like sails, tiny sails, moving on top of the sparkling water. But really they were fins on the backs of fishes. The alewives had begun their spring voyage.
The alewives belong to the Herring family. They are about twelve inches long when they are grown. Their backs are dark blue and their sides are silvery. That is the way they look when they are in the water.
The alewife belongs to the Herring family.
If you take one up in your hands and hold it in the sunshine for a moment, the flat overlapping scales look like glistening jewels. The scales on the back are deep blue, almost black, shading to paler blue. Those high on the sides are like opals, gleaming pink and blue and fiery gold and green. The lower scales are white, like pearls.
Most of the time the alewives live in the ocean, but in the spring they swim into fresh water.
The alewives waiting at the mouth of Holiday Stream were so close together that they touched one another. Their tails all pointed toward the sea, and their heads all pointed upstream. They were eager to go away from the ocean, and yet they waited. It was easy to see what held them back. The falls near the mouth of the stream were too high for them to climb. So they were trapped between the ocean to which they would not return and the falls they could not pass.
The tide was out. Shells and seaweeds which had been tossed by the last high water, now lay far up the shore in the sunshine. The barnacles clinging to the water-darkened piles of the nearest wharf showed how low the sea was, for it was only when the tide went out that the barnacles were uncovered.
Then something happened. The lowest barnacles that had been in sight were under water again. They had been clinging to the same spot all the time. They had not moved at all. As they had not gone down, the water must have come up. Yes, that was what had happened. The tide had turned. The sea was rising in the bay.
The waves slapped the smooth stones and swished along the shore. The nearest shells and seaweeds were no longer in the sunshine. They were in the sea again. As the water pushed farther and farther up the shore and crept higher and higher on the piles where the barnacles clung, it flowed into the mouth of Holiday Stream until it reached the falls.
The water that poured over the top of the falls was fresh. The water that washed against the foot of the falls was salt. And there, in the sparkling bay where the stream mixed with the sea, the little sail-shaped fins of the waiting fishes showed in the sunshine.
You can guess what was happening. The ocean was slowly climbing the falls and lifting the alewives with the tide. At last, where there had been high falls, there were hardly more than rapids.
The eager fishes waited no longer. They went up the rapids and struggled against the current with all their strength. Those hurrying in front were pushed by those that followed fast behind.
Many of the alewives mounted the rapids by plunging straight up the current. They went quick as flashes, their backs looking like blue streaks under the water. They did not leap out of the stream in climbing, as salmon and trout do, but took their chances in the current.
Some of the fishes were tossed back by the water, and they tried again and again to get through the rough places. Often they lost their balance in the swift and whirling current and were thrown over on their sides. Such fishes would flop along sidewise and push against the rocks with their fins.
It was hard work, but the fishes seemed to like putting their strength against that of the stream. Not one of all the many thousands gave up trying. Not one left his struggling comrades and went back to swim easily in the sea.
They were very quick and they tried very hard, but there were so many thousands of them that they could not all crowd into the stream above the rapids before the tide turned.
As the tide went out and the rapids again became falls too steep for fish to climb, those that had not gone over the top halted. They waited with their heads toward the falls and their tails toward the sea. As the water went lower and lower and they sank with it, not one went back to swim in the broad ocean. They stayed crowded in the narrow mouth of the stream.
What held them there? They had spent most of their lives in the great salt sea. Why should they leave it and seek fresh water? How had it come about that the numerous fleet of tiny black sails had entered port together? What strange and wonderful feeling had come to them out in the ocean with power to turn them all so suddenly, all so eagerly, toward the gushing stream?
You might as well have asked the bobolinks why they had come. They were singing just then over the fields. There was joy in every note. What had happened to them in the pleasant South American places? Why did they fly back again every spring, gladly and with song?
The bobolinks had an errand in northern meadows, an errand of eggs and nests and young.
Well, the alewives had an errand too. I do not suppose they thought about it that way with their little brains. Perhaps there was something about the spring sunshine that drew them toward the shallow water near the shore. Perhaps some of the fresh water reached them as it rushed out of the mouth of the stream, and seemed good. Perhaps, in the springtime, swimming up into the fresh current seemed so pleasant that they could not help going.
We can only say "perhaps" because we do not really know how the fishes felt about their journey. But we may be sure that they liked it from the way they acted. And we may guess that if they could sing, they would have gone on their way with glad sounds, as the bobolinks go.
But after the alewives had pushed through the rapids at high tide, they were tired. Soon they came to a place sheltered by rocks, where the water was quiet as a pool. There they rested, swimming so slowly that they hardly seemed to move. It took them a week to reach Six-foot Falls, which was about half a mile away. The weather that spring was very cold, and the alewives were twice as long reaching the falls as they had been the year before, when the weather was warmer.
You might think Six-foot Falls too high for them to climb. They found a way at one side, however, where the rocks were like rough steps. They went up through that passage, and they went quickly. There was nothing slow about the alewives when they swam against swift water.
About a week after they left Six-foot Falls, the first of the alewives reached Holiday Pond, and the others followed when they were ready. They seemed contented in the pond and stayed there for some time. During their visit to Holiday Pond, the alewives laid their eggs.
At last the visitors from the sea found Holiday Pond.
As one alewife could lay sixty thousand eggs or more, there were soon a great many eggs in the pond. The eggs were small and sticky, and they were placed in gluey masses on stones and other objects rather near the shore.
After the alewives had laid their eggs, they did not seem to care much for the fresh water of pond and stream. Perhaps they were hungry, for they had not eaten since they left the sea. Be that as it may, they went out of the pond in small companies from time to time.
It was easy to tell when they were ready to go, for they gathered in little groups where Holiday Stream ran out of the pond. There they waited, their moving tails pointing downstream. Then, when they were ready, off they started, tail-first, for the ocean.
The eggs which had been left in shallow water were warmed by the sun, and they hatched in a few days.
When the little fishes began to swim, Holiday Pond was a lively place. The fresh water was good for their health, and they found plenty of food to make them grow. They hunted in the pond, and before the summer was over they looked much like their fathers and mothers, except for size.
They had grown to be two or three inches long, when they started on a strange journey. It was still warm weather and the pond quite as pleasant as ever, though perhaps there was less food in it. They may have been hungry, or tired of freshwater fare.
Nobody knows exactly why they left Holiday Pond, but leave it they did. They went down Holiday Stream, over Six-foot Falls, through the rapids, and into the sea. And they seemed to be having a good time all the way.