Part 4
What about the alewives during their years in the sea? Very little seems to be known. According to _Fishes of the Gulf of Maine_ by Bigelow and Schroeder: “The alewife is as gregarious as the herring, fish of a size congregating in schools of hundreds of individuals (we find record of 40,000 fish caught in one seine haul in Boston Harbor) and apparently a given school holds together during most of its sojourn in salt water. But they are sometimes caught mixed with menhaden, or with herring. Alewives, immature and adult, are often picked up in abundance in weirs here and there along the coast, and it is likely that the majority remains in the general vicinity of the fresh-water influences of the stream-mouths and estuaries from which they have emerged, to judge from the success of attempts to strengthen or restore the runs of various streams.... But it is certain that some of them wander far afield, for catches up to 3,000 to 4,000 pounds per haul were made by otter trawlers some 80 miles offshore, off Emerald Bank, Nova Scotia at 60 to 80 fathoms, in March 1936.”
They also say, with circumspection: “It seems likely from the various evidence that the alewives tend to keep near the surface for the first year or so in salt water, and while they are inshore when older. But practically nothing is known of the depths to which they may descend if (or when) they move offshore, there being no assurance that those taken by trawlers were not picked up, while the trawls were being lowered or hauled up again.”
The view that most of the alewives stay in coastal waters near the fresh waters where they were hatched seems to be generally accepted, though the proof is sometimes hard to find. They occur at various depths in the sea as well as considerable distances offshore. They are as likely to be found in deep as in shallow waters. I am told there are recorded views that landlocked alewives winter in the deep waters of Lake Ontario, and that shad, a close relative, have been found with near-bottom animals in their stomachs. I also have the information that during the summer of 1956 draggers in Passamaquoddy Bay were catching a large quantity of alewives and that “it looked as if they were near bottom.” Despite some having been picked up in weirs close to the shore at various times during the year, they have not commonly, if at all, been taken by draggers on the continental shelf except when approaching the shore during the spawning season. In other words their oceanic whereabouts have not been pinned down. All we can say, still presuming stocks are local along the coast, is that mature alewives move in from deeper waters offshore in the springtime, progressively later from south to north.
What might seem to be a curious exception to the rule is a run in St. John Harbor, New Brunswick, that occurs in the dead of winter. Alewives are taken there in late January and early February; but I find that this may not be so peculiar a phenomenon as it sounds. To begin with, St. John Harbor is joined with the Bay of Fundy, and when the fish move into it they are still at sea. The reasons for their move at that time is not clear, but as there appears to be winter seining of alewives farther down the coast along the shores of neighboring Charlotte County, it is at least not unbelievable. The alewives then start through the harbor and move up the St. John River to their spawning grounds in the usual migratory months of April and May. I am told by the St. Andrews Biological Station that: “The inflow of the St. John River, particularly in April and May, dilutes the harbor water, especially at the surface. Whether it attracts alewives to the harbor or carries them there by deep circulation is a question.” This last point brings up the problem, quite beyond my powers to understand, of how the alewives orient themselves, how they find or are attracted to the waters in which they spawn. We may know very little about their life at sea, but their ability to find a particular stream or river may be an even greater mystery, which is not lessened by the probability that they have been there before. Whether as first-year spawners or repeaters the alewives seem to come back to the streams from which they migrated during the first summer and fall of their lives--when they were not more than a few inches in length. Not consistently--a certain amount of shifting between schools and change of locale may go on. Many go astray like migrating birds, or men out of crowds perhaps, but in general they do tend to return to their home streams. As a proof of this, ponds that were empty of alewives have been stocked with them, and the spawn returned as adults in three or four years’ time. This is the “parent stream” theory. With salmon it has apparently been shown to be a fact; although it is not so much the stream they were born in to which they return as the stream in which they grew up. Salmon eggs have been taken out of one river, moved to another, and then the hatched fry were tagged. They migrated to the sea and returned to spawn in the second river where they had their growth.
So what is to account for the alewives being able to find a “parent stream” that might be only a few yards wide, out of all the great stretches of the Atlantic coastline? They left it when they were no more than one and two-fifths to four inches long, but somehow, growing up in the sea, they must always have been oriented to that home base. They may have stayed reasonably near by, but even so this ability is hard to fathom.
Disregarding the question of how they arrived at that point, how could they tell one stream from another? They enter innumerable rivers, streams, inlets, some of them in close proximity. One theory has it that they are able to find their home waters by their characteristic odor, their special composition, to which they were conditioned when young. Even so, how did they get there? How can fish way offshore in waters of a consistent temperature, without any landmarks, tell which direction will take them to their home street? It is quite likely that they would be able to detect the outlet waters where they merged with the sea, but a stream may not reach very far, perhaps a few hundred yards or more at low tide, before being totally absorbed. All the way along the coasts, rivers and streams pour in fresh water, mixed in the estuaries so that it is brackish when it reaches the sea. The sea water increases in salinity as it gets deeper over the continental shelf. An alewife may detect very slight differences in salinity comparatively far out, but we are still not much closer to realizing how it finds its way.
What it amounts to is that no particular factors seem to be able to explain this directional ability of theirs. Not the response to changing currents in the spring sea, not the perception by fish of varying pressures in salt water, or of differences in salinity, nor their possible ability to use the sun as a reference point in navigation ... none of these approaches have yet solved the great mystery. Do they have some special sense, some perceptiveness, about which we know nothing? Scientists have measured and probed their reactions for a long time, but so far have not found any evidence of a special sensory ability. Biologically, fish do have several unique characteristics. For example, they have an “air bladder” by means of which they are able to adjust themselves to changing densities in the water. They also possess a “lateral line” organ, consisting of a tube or canal under the skin filled with mucus and connected to the nervous system. This sense, closely associated with hearing, enables them to detect vibrations of a very low intensity in the water and to avoid obstacles, such as an approaching bank or another fish. Aside from that, fish can smell, they have sight, and they have a sense of touch and taste.
These known senses are what scientists count on in investigating the migratory behavior of fish. They test their responses to different stimuli. On that basis, one of the most recent directions to be explored centers around the environmental factors which the fish are subjected to, such as currents, temperatures, the physical and chemical nature of the waters through which they swim. These factors are supposed to guide them successively on their migrations and to be so consistent year after year that the responsive fish return to their streams of origin because they never got off the track. Different schools, or age groups, of alewives would go to separate streams, because they responded differently, as Gerald B. Collins puts it in his study of alewives at Bournedale, “to the existing patterns of environmental stimuli.” Homing, from the environmentalists’ point of view, is neither a matter of memory nor mystery.
I do not have enough knowledge behind me to discuss such a method or approach, but it does seem to have the advantage of comprehensiveness, of taking the whole journey in. It does not depend on any single factor to explain migratory behavior, and it provides a good long track of exploration, step by step.
Whether the migrant fish behave as mechanically as this suggests, or whether the factors involved are separately either as consistent as they are supposed to be, or amount in the aggregate to as much as they should, remains to be seen. We are still in the realm of theory, however rationally expressed, and do not know yet how the fish find their destination.
Can a fish judge its course by the sun, or by the circulation of the waters of which it is so much a part? Can we talk about a homing instinct, or orienting ability, in connection with it? What are we defining? I don’t think I beg the question by finding it pertinent that civilized human beings have to some extent lost their ability to find their way in the woods, or no longer rise and sleep with the sun, or that they are not aware of the changing tides. Some old directional knowledge may still be innate in us, though we seem to think we have no need of it. Our puzzle, or lack of definition, may lie with ourselves as much as the alewives. In any case, what we try to find out by fact or abstraction is already known to the fish.
They are still ahead of us. So much of their motion seems to be a part of the race as a whole, synonymous with its great water world, that it is almost as if they found their way like the wind and tides, elemental forces that we find it hard to evaluate. We try to pin down that which expands immeasurably beyond us.
VII
Port of Entry
With a certain amount of half-determined knowledge behind me, I decided early one morning to follow up the question of how far the brackish waters of the Stony Brook outlet extended into Cape Cod Bay, and so went down to Paine’s Creek. This is the place where the stream, which has been winding through tidal marshes like a small river, ends in a basin where several dories are moored, then takes a last turn and long curve, cutting through low dunes anchored by beach grass that border the sands. I saw a kingfisher rising up over the creek, a green crab shifting along the shelving bank; and on the beach were the remains of a black duck, sodden, bedraggled, the feathers loaded with wet sand, the breastbone sticking up like the white prow of a helmet, flies buzzing over it--the smell of salted carrion around it.
The sound of the waters along the creek is constant and musical, following and followed up, broadly roaring, rushing, or slipping lightly, as they rise, pushed back by the incoming tide, or run out low and easy with the ebb. At low tide these creek waters spread their channels and fingered rivulets some three hundred yards straight out over the sands, to a point where they are joined by the waters of Quivett Creek which has an inlet a few hundred yards upshore to the west. Then the one channel finds its way past a fish weir until it is lost in the salt waters coming in over a long bar in the distance. The alewives also swim into the other creek; though not in the numbers that run up Stony Brook, because of less access to spawning grounds beyond.
The tide was well out when I started to follow, or rather taste the fresh water over the sands. The Brewster flats, as they are called, were alive with light and constantly changing where they stretched out on the earth’s curve. Minor investigation took place in maximum horizons. I walked toward the weir, or fish trap, one of three in the distance, long-poled stockades a quarter of a mile or so apart, hung with nets like veils or the peaked coifs of nuns. A silver sun was beginning to lift through sheets of low fog, and a cool wind blew across the sands. It made my ears boom with that hollow sound of deep marine that you hear in a shell. I saw a small flock of brant standing off, their heads alert for danger, ready to thrust up and go when I came. I approached lines of brown dunlins, red-backed sandpipers, sanderlings, black-bellied plovers, which stood and scurried, peeped and cried, flew forward into the wind for short stretches, and came down again.
As the sun rose farther up, clouds began to be reflected in the lanes between the ribbed sands, and there were thousands of gulls standing in a silver, immeasurable distance, while those sharp, light arrows, the terns, flew overhead. The flats with their brown deserts, their lakes, and pools, and veins, were like the patterned floors, the reaches of the great civilizations of man. The dawn fogs blew off. I was waking up to an architecture of space.
Now from these tidal areas the plains of the sea rove out indefinitely. You can get a look at the universal map without benefit of signposts, and the coming on of fish represents great standards of inevitability.
“But look,” a scientist might say, “in this unlimited space of yours, the mating animal only has a tiny area to travel in; a few miles at sea, if in the case of the alewives, they do stay offshore, and perhaps two or three miles inland. They are limited in space, and limited in numbers accordingly.”
True, but we might add that it is this limitation, in alewives at least, that makes increase possible. They are one of the most easily managed of all marine species. Clear out the obstructions in their way; restock a lake and river system, or pond and stream, and the fish return, the population rises. Alewife management depends on their almost relentless drive to go back where they came from. No life insists on its locality more strongly. Home in their case is a definite route, a round way, small if you like, but spinning in larger circles, where birth leads back to its necessity.
So I walked the sea lands, following the alewives’ avenue of approach. Well beyond the weir I began to get in too deep to qualify as an investigator. I judged that the brackish water of the outlet went at least five hundred yards out, and probably several hundred yards more than that, before it flowed into the salt waters of the Bay and then was lost in them. It seemed, during low tide at least, that the alewives might detect the fresh water reasonably far out in the Bay, disregarding the question of how they arrived at that point.
As I went back across the wind again, under the hovering, crying birds, and saw where the waters of the two creeks came out, that strange fish knowledge of where to go was still unbelievable. I imagined alewives coming in here, or to a shore where there were even more creek inlets fairly close together, and wondered whether the schools joined in the Bay like concentric circles and then separated, each going to the stream in which it grew up. I also wondered about that supposed chemical sense, or sense of odor, that might explain the alewife’s knowledge of its home stream. Would not the composition of the waters of any one stream change greatly at various times of the year? It must be very different in the hot summer, when the little alewives come down to salt water, from the cool months of spring when the adults came in. Would that not be just as important a factor as the stream’s difference from another close by?
Two miles farther up along the shore is another inlet at the mouth of Sesuit Creek. Many years ago the Sesuit and Quivett inlets were interconnected at some point back in their tidal marshes; and before the roads and banks were built that now divide them there was also more access to several ponds in the vicinity, both large and small. Since the glacial ponds of Cape Cod seem to fill up and dry out in time, turning to wooded or grassy hollows, it is possible too that the alewives had even more entryways, and went even farther inland, having longer fresh-water routes to travel--water veins open and flowing everywhere. In any event, the alewife population now starting up these two inlets is very small compared to that of Stony Brook, which shows that the fish are balanced in numbers according to the relative ease or difficulty of getting inland to adequate spawning grounds. In part, it also seems to be an added proof of the parent stream theory. The fish know their way. For whatever reason, and whether or not they are entirely consistent in coming back to the exact stream, it seems to us that they have a remarkable sense of direction, although, for all we know, it may not be any more remarkable than the accuracy of the tides or the timing of the sun.
VIII
The Common Night
Did the alewives choose the night or late evening hours to come in by? So I had been told. By daylight evidence, the fish population increased at the Herring Run on the mornings following a nightly high tide. I had also heard that there were more alewives running during the tides of the full moon, in the farthest monthly reaches of ebb and flood; but this was a correlation that would be hard for me to make without more years to judge by. In the middle of May on the days just after the first quarter of the moon, which came on the sixteenth, the fish seemed to be running just about as hard as they did during the days preceding the full moon in April, which had appeared on the twenty-fourth. Judging accordingly, it seemed as though their migration had its own ebb and flood during those months. All this was not much better than impression plus hearsay, but there seemed to be some justice to the night tide theory, so, to begin with, I went down to the shore late one evening during an incoming tide to see if there might be any sign of the alewives.
About eight o’clock, an hour before high tide, the tide was running strongly in at Paine’s Creek. The channel in the marshes flooded over its banks and marsh grasses were floating and stirring as the swaying waters rose around them. It was near dark. I could see some seaweed flinging by against the sandy bottom at the mouth of the creek, and a big, ghostly green eel slithered up at the edge of the bank the waves were licking, seemed to look up at me, looped back into the water, and disappeared; but it was too dark to see much more than those black clumps of seaweed racing by. I saw a group of gulls standing in shoal waters beyond the beach, where waves were rolling in hard under a steady northwest wind. The sun’s cauldron had dropped down, a raw, glistening orange-red, into the sea and back of the curved horizon, leaving its horizontal flush behind.
[Illustration]
I walked back under the lee of the sand banks bordering the curving creek. The tide was pulsing and roaring, its waters loping in to the creek which began to turn a harder, darker blue under the sky. Then I began to hear the innumerable soft slaps of fish breaking the surface. The alewives were making their entry from the sea.
And the gulls proclaimed their coming. Out in the Bay, they began to gather by the hundreds, clambering up with a scrambled yelping and hollering. The last smoky, red line of sunset was disappearing and they hovered over it in a maddened, high, wide swarm like huge bees. It grew darker, and a black-crowned night heron, or “quawk,” sometimes “quok,” a name true to the sound it makes, flew by with rounded wings against a star. The gulls began to disappear, streaming faintly like ashes against the last fires on the sea, but still crying vastly and collectively toward a world of distances. And in terrible simplicity, the alewives were swimming toward the inland gauntlet they would have to run, having a title, by their common, wild, and ancient advent, to all great kindled things. Who will see more than that in his short life, with its many meetings and separations?
I by an old and natural right felt a fierce water-deep wonder of the spirit. The beyondness in me went back to its beginnings. I thought of the nights on which children I have known were born, and of the voyages of war, leave-takings at railroad stations and at ports of embarkation, and of dreams in which I struggled toward new meetings and other lives. The wind blew through the arches of the stars, and the surfaces of the dipping earth, water, and sky in their lasting communion made me dizzy. I felt a cold inevitable grandeur, below consciousness, a swim and go in an uttermost wild world, past home or my life’s memory.
So by this evidence the alewives came in at night, and, as a further discovery not to be denied, so had I. Perhaps it was the closest I would ever get to the non-human fish in a darkness where all the components of existence ran the same race. That real depth, fish-oriented, nakedly omnipotent, fills men when they recognize it with more awe than their limited worlds can encompass.