Estuary

“ This appeal is not always a charm, for there are estuaries of a particularly dispiriting ugliness: lowlands, mudflats, or perhaps barren sandhills without beauty of form or amenity of aspect, covered with a shabby and scanty vegetation conveying the impression of poverty and uselessness. Sometimes such an ugliness is merely a repulsive mask. A river whose estuary resembles a breach in a sand rampart may flow through a most fertile country. But all the estuaries of great rivers have their fascination, the attractiveness of an open portal. Water is friendly to man. ”

“ The colossus, so deeply wounded that his trail threw up great clots and bubbles of red foam, swam onward 17 several miles up the estuary. He realized now that that patch of sunny beach was just a death-trap. But in the middle of the estuary, far out from either shore, far removed from the unseen, lurking horrors of the fern forests, spread acre upon acre of drowned marsh, overgrown with tall green reeds and feathery “mares’ tails.” Through these stretches of marsh he ploughed his way, half-swimming, half-wading, and felt that here he might find a safe refuge as well as an unfailing pasturage. ”

“ A gleam of light falls upon a broad expanse of the estuary beyond that point under which the schooner lies at anchor, and brings out the thickly wooded banks of an opposite shore, causing us to note the fact that, for some reason or other, no timber seems ever to have spread down so far toward the sea on this side of the stream, or where the settlement stands, since nothing but scattered copses of alder- and willow-bushes grow on its suburbs or anywhere else as far as an eye can range up the valley. ”

“ The great mass of the limestone head bounding our estuary to the southward loomed black and sullen against the delicate pearl clouds, through which an unseen sun was endeavouring to diffuse some measure of day to our little valley. To seaward the tide had receded far, and the chill white lines of water tossed to the wind beyond a wide stretch of sand. To landward the dun mist of morning hung, blotting out the distant hills and the woodlands, leaving in view only a stretch of marshy pastures and the houses of a tiny village. ”

“ At your feet the heather commenced the landscape, then came golden corn-fields and green pasture-lands, far and wide, until they reached the yellow undulating sand-hills that fringed the margin of the broad estuary, the sparkling waters of which, in the glow and fulness of the rich sunshine, gave life and animation to the scene, the interest of which was deeply enhanced, when on a day of high-tide, numbers of vessels might be seen spreading their snowy canvas in the wind as they set out on their distant and perilous voyages. ”

“ Marine testacea.—The aquatic animals and plants which inhabit an estuary are liable, like the trees and land animals which people the alluvial plains of a great river, to be swept from time to time far into the deep; for as a river is perpetually shifting its course, and undermining a portion of its banks with the forests which cover them, so the marine current alters its direction from time to time, and bears away the banks of sand and mud against which it turns its force. ”

“ Here at high tide extends a sheet of water large enough, when the wind blows up the estuary, to breed waves that break in foam and spray against the barges, while at the ebb acres of mud flats are disclosed on which the boats lean slanting till the flood lifts them again and makes them strain at the wheezing ropes that tie them to the quay. ”

“ Where sea and river meet, Nature draws no sharp dividing line. Here the indeterminate boundary zone is conspicuous. The fresh water stream merges into brackish estuary, estuary into saltier inlet and inlet into briny ocean. Closely confined sea basins like the Black and Baltic, located in cool regions of slight evaporation and fed from a large catchment basin, approach in their reduced salinity the fresh water lakes and coastal lagoons in which rivers stretch out to rest on their way to the ocean. ”

“ Accordingly, when training works are started at the head of a sandy estuary, provision should always be made in their design for their eventual prolongation to deep water at the mouth of the estuary, to ensure the formation of a stable, continuous, navigable channel. ”

“ Training Works through Sandy Estuaries.—Many tidal rivers flow through bays, estuaries or arms of the sea before reaching the open sea, as, for instance, the Mersey through Liverpool Bay, the Tees through its enclosed bay, the Liffey through Dublin Bay, the Thames, the Ribble, the Dee, the Shannon, the Seine, the Scheldt, the Weser and the Elbe through their respective estuaries, the Yorkshire Ouse and Trent through the Humber estuary, the Garonne and Dordogne through the Gironde estuary, and the Clyde, the Tay, the Severn and the St Lawrence through friths or arms of the sea. ”

“ Only in one small panel do we remember any deviation from the type of slow-running river water that he usually affected, and there we are shown small craft exposed to the mean spiteful choppiness of a wind-exposed estuary, an unconvincing picture from the utter monotony of treatment of beaten water. ”

“ Structurally the estuary may represent the long-continued action of river erosion and tidal erosion confined to a narrow channel, most effective where most concentrated, or an estuary may be the drowned portion of the lower part of a river-valley. In a map of Britain showing sea-depths it will be observed that under the Severn estuary the sea deepens in a number of steps descending by concentric V’s that become blunter towards deep water until the last is a mere indentation pointing towards the long narrow termination of the present estuary. ”

“ From the scattered way in which remains of the larger terrestrial animals occur in the Wealden, and the intermixture of pebbles of the special appearance of those worn in rivers, it is also inferred that the estuary which once covered the south-east part of England was the mouth of a river of that far-descending class of which the Mississippi and Amazon are examples. What part of the earth’s surface presented the dry land through which that and other similar rivers flowed, no one can tell for certain. ”

“ The estuary attracts a good number of wild fowl, duck and shore birds, in winter, and as a consequence is much frequented by sportsmen. One day the ferryman took one of these gentlemen, a visitor from a distance, across the river, and was not half-way over before the seal appeared as usual and with its head well up swam after the boat, and gaining quickly on it was soon not more than an oar's length from the stern. ”

“ The tip of this sound, which faces the east, forms, with a horseshoe-shaped headland, a pocket which, at low tide, is mostly dry. In this inlet are some logs to which are fastened black feathers, bunches of reeds and snail shells, which gave me the idea that they are fishing floats, since they are in the middle of the water. Beyond three leagues from the entrance of this estuary I estimate that nowhere is it possible to anchor, due to the lack of shelter. ”

“ When once a short cut has been made for a great river, it is no easy matter to turn the stream back into its old tortuous course; and, when once an estuary has got thoroughly silted up, it is yet more difficult to restore it to its old condition. ”

“ A storm-beaten coast, with plentiful havens, in the mouth of a large estuary abounding with fish, enticed the seals to the shore and made them an easy prey to the Indians, but time has driven them to the present rookeries which now afford them protection. ”

“ Stand on the bank of an estuary or river up and down which a great tidal current ebbs and flows; you [42] will see the water copiously charged with sediment which the tide is bearing along. Engineers are well aware of the potency of the tide as a vehicle for transporting stupendous quantities of sand or mud. A sand-bank impedes the navigation of a river ”

“ The uncertainty of their movement was, of course, increased by any change of the estuary of the stream whose eddying waters created them. Many lesser streams made new estuaries for themselves in the high-water season; for the flood-tides found new courses which thereafter became the regular channel. ”

“ Restricting ourselves to the vast plain west and south-west of the Wash, the silted-up estuary, rather than the river delta of the Welland, Nen, and Ouse, it may suffice to say that, while works were executed so far back as Roman times, the first great effort for the reclamation of the land dates from the seventeenth century. ”

“ The river might, therefore, be navigated by boats of considerable burden, if the lake admitted of the same facility; but I am decidedly of opinion, that the latter is generally shallow, and that it will, in the course of years, be filled up by depositions. It is not, however, an estuary in any sense of the word, since no part of it is exposed at low water, excepting the flats in the channel, and the flat between the lake and the sea. ”

“ Again, the tides and currents of the estuary, by changing their direction, might sweep away a considerable mass of alluvium from the bottom, laying bare a canoe that may have foundered many centuries before. After the lapse of so long an interval, another vessel might go to the bottom in the same locality and be there covered up with the older one on the same general plane. ”

“ Salmon coast along such an extent of our shores before reaching their destination that bag and coast nets miles away may take heavy toll of the fish that are seeking your estuary, even though they would have a free run up your river if once they could attain it. ”

“ A little further along the shore of the broader water is another little estuary or cove, only a few hundred yards in its total length, but that length extends toward the creek on the other side, so that only about half a mile or less of swamp and thicket separates the two. ”

“ It has been seen that the conditions in an estuary are not favorable for supporting life. The tidal scour, the churning up of the water, keeping the sediments constantly in suspension, the sudden change in salinity twice every day, are environmental factors not at all conducive to attract marine animals which can find more stable and beneficial conditions along the coast on both sides of the estuary. ”

“ For, in the course of those changes in physical geography which may take place during the gradual emergence of the bottom of the sea and its conversion into dry land, any spot may either have been a sunken reef, or a bay, or estuary, or sea-shore, or the bed of a river. For this reason it would be unreasonable to hope that we should ever be able to account for all the alluvial phenomena of each particular country, seeing that the causes of their origin are so complicated. ”

“ They differ entirely from an estuary in the fact that they are bounded seawards by a rocky sill, covered by shallow water, and they deepen inland for some distance before the bottom again curves up to the surface. ”

“ Every dock excavation, however, does not necessarily cut through the submerged forests, for channels in an estuary are constantly shifting, and many of our docks happen to be so placed as to coincide with comparatively modern silted-up channels. ”

“ Estuary and Shore Deposits.
Rivers which discharge themselves into the ocean, where tides and currents break with a certain regularity the quiet of its waters, exhibit always at their mouths, and often along the lower part of their channels, another set of phenomena.
Where the tide enters a river's mouth, and periodically combats the freshes, these are "backed" to certain distances, their motion is nearly destroyed for a time, and the sediment, which was only suspended by the agitation of the water, is dropped in the interval of quiescence. ”

“ As soon as the Francis was off the bar, therefore, they proceeded up the estuary for a distance of nearly two miles and secured their vessels in shallow water, where they could be careened at low tide. ”

“ On the other hand they are steadily being filled up with growing vegetation and turned into peat mosses.
The origin of these shallow freshwater lakes, which form a characteristic feature in the scenery of East Anglia, has been much debated; but with the knowledge obtained from a study of the submerged forests the explanation is perfectly simple. During this period of slow submergence each of the shallow valleys in which the broads now lie was turned into a wide and deep navigable estuary, which extended inland for many miles. ”

“ The tide-flow may be more beautiful and obvious seen from the high shores of certain estuaries, as, say, from the Falmouth uplands, or from the hillsides of our narrow Highland sea-lochs, but the mind is deeplier impressed and the imagination compelled by the more obscure, menacing, and almost terrifying swift arrivals along vast shallow estuaries, such as The Wash or the inner reaches of Solway Firth or by the Sands o’ Dee. ”

“ Most of our sea-side places of resort lie at the mouths of small valleys, which originally gave the fishermen easy access to the shore, and later on provided fairly level sites for building. At such places the fishermen will tell you of black peaty earth, with hazel-nuts, and often with tree-stumps still rooted in the soil, seen between tide-marks when the overlying sea-sand has been cleared away by some storm or unusually persistent wind. ”

“ For the coast-dwellers, the sea-shore, with the rocks which are the refuge of the shell-fish, is the inexhaustible playground of the children. Looking down in the clear deep water of the archipelago they see the coral reefs, the bright flower-gardens of marine plants, and shoals of striped, banded, crimson-tailed, and green-finned fish, which, in the eastern seas, glitter with tints of gold and silver. ”