The mud brought down by it, calculated at 7150 lb an hour at Bagdad, is not deposited in marshes to form alluvium, as in the case of the Euphrates, but although in flood time the river becomes at places an inland sea, rendering navigation extremely difficult and uncertain, the bulk of the mud is deposited in banks, shoals and islands in the bed of the river, and is finally carried out into the Persian Gulf.
These fish frequent rocky shoals off the eastern coast and are caught in numbers outside Port Jackson for the Sydney market.
Its most extreme point is called Buddon Ness, off which are the dangerous shoals locally known as the Roaring Lion, in consequence of the deep boom of the waves.
But it frequently happens that the dam at the head of the Hindieh is carried away, and, a free channel being thus opened for the waters of the river to the westward, the Hillah bed shoals to 2 or 3 ft., or even dries up altogether, while the country to the west of the river is turned into lakes and swamps.
At the eastern extremity of the Coastal Plain Region an outer coast line is formed by a chain of long narrow barrier beaches from which project capes Hatteras, Lookout and Fear, whose outlying shoals are known for their dangers to navigation.
The harbours along the sounds and in the estuaries of the rivers are well protected from the storms of the ocean by the long chain of narrow islands in front, but navigation by the largest vessels is interrupted by shoals in the sounds, and especially by bars crossing the inlets between islands.
South of this enclosed depression is another great hydrographic barrier which parts it from the low plains of the Amur, of China, Siam and India, bordered by the shallows of the Yellow Sea and the shoals which enclose the islands of Japan and Formosa, all of them once an integral part of the continent.
The Clupeidae, or herrings, are most abundant; and anchovies, or sardines, are found in shoals, but at irregular and uncertain intervals.
In such immense shoals do these fish appear in some of the smaller streams that numbers are squeezed out on to the banks and there perish.
Long, with a minimum width of 6 m.; the water is generally deep and the shoals lying near the usually travelled routes are well marked.
It feeds on mackerel, pilchards and herrings and, following the shoals, is often caught by fishermen in the nets along with its prey.
Detailed study of the cod shoals also showed that their composition was continually changing: in some years the shoal is composed of younger or older fish than the average and with this latter variation there are changes in the quantities of oil yielded per t,000 fish.
The changes in the composition of the shoals, as regards the proportions of the various " year-classes," are to be correlated with oceanographical changes (see below).
Towards the mainland the water shoals, and the best anchorage is under the lee of the island.
But the vessels were wrecked upon some shoals about one hundred leagues to the south of Maranhao; the few survivors, after suffering immense hardships, escaped to the nearest settlements, and the undertaking was abandoned.
Its greatest depth is 738 ft., its average depth much in excess of that of Lake Erie, and it is as a general rule free from outlying shoals or dangers.
The coast-line is fringed with small islets and shoals and reefs, which make navigation dangerous.
The western coast of Yemen, like that of Hejaz, is studded with shoals and islands, of which Perim in the Straits of Bab-el-Mandeb, Kamaran, the Turkish quarantine post, 40 m.
The south coast is free from the shoals that imperil the navigation of the Red Sea, and in Aden it possesses the only safe natural harbour on the route between Suez and India.
Extremity of Nantucket Island is Siasconset (locally 'Sconset), a summer resort of some vogue; it has a Marconi wireless telegraph station, connecting with incoming steamers, the Nantucket shoals lightship and the mainland.
Thus far the Ganges has been little more than a series of broad shoals, long deep pools and rapids, except, of course, during the melting of the snows and throughout the rainy season.
Beyond this city the navigation is conducted by native craft, - the modern facilities for traffic by rail and the increasing shoals in the river having put an end to the previous steamer communication, which plied until about 1860 as high up as Allahabad.
This species swarms in some years in prodigious numbers; in Pennant's time amazing shoals appeared in the fens of Lincolnshire every seven or eight years, No instance of a similar increase of this fish has been observed in our time, and this possibly may be due to the diminished number of suitable breeding-places in consequence of the introduction of artificial drainage.
Long, and protected by a lighthouse and a fort, would admit vessels of considerable tonnage; but it has been allowed to silt up until it shoals off from 2 4 ft.
Sir John Murray finds the source of the phosphoric acid to be the decomposition of large quantities of animal matter, and he illustrates this by the well-known circumstance of the death of vast shoals of fish when warm Gulf-Stream water displaces the cold current which usually extends to the American coast.
It is allied to the European species of shad and pilchard, and, like the latter, approaches the coast in immense shoals, which are found throughout the year in some part of the littoral waters between Maine and Florida, the northern shoals retiring into deeper water or to more southern latitudes with the approach of cold weather.
The anchorage in the roadstead is good, but the bay shoals for a long way out, and is exposed to swell from south-west and south.
The water is muddy; and the course for shipping considerably exceeds in length the distances given above, by reason of the numerous shoals it is necessary to avoid.
The great shoals that visit the North Sea annually.
Finally the sea had overwhelmed Atlantis, and had thenceforward become unnavigable owing to the shoals which marked the spot.
Paulo in Brazil supplied Sars with representatives of all the three in his Norwegian aquaria, in some of which the little Macrothrix elegans " multiplied to such an extraordinary extent as at last to fill up the water with immense shoals of individuals."
All the fossil plants and animals of every kind are brought from this continent into a great museum; the latitude, longitude and relative elevation of each specimen are precisely recorded; a corps of investigators, having the most exact and thorough training in zoology and botany, and gifted with imagination, will soon begin to restore the geographic and physiographic outlines of the continent, its fresh, brackish and salt-water confines, its seas, rivers and lakes, its forests, uplands, plains, meadows and swamps, also to a certain extent the cosmic relations of this continent, the amount and duration of its sunshine, as well as something of the chemical constitution of its atmosphere and the waters of its rivers and seas; they will trace the progressive changes which took place in the outlines of the continent and its surrounding oceans, following the invasion§ of the land by the sea and the re-emergence of the land and retreatal of the seashore; they will outline the shoals and deeps of its border seas, and trace the barriers which prevented intermingling of the inhabitants of the various provinces of the continent and the surrounding seas.
From the shore are the bleak and nearly barren Isles of Shoals, nine in number, a part of which belong to New Hampshire and a part to Maine.
Samuel de Champlain discovered the Isles of Shoals and sailed along the New Hampshire coast in 1605, and much more information concerning this part of the New World was gathered in 1614 by Captain John Smith, who in his Description of New England refers to the convenient harbour at the mouth of the Piscataqua and praises the country back from the rocky shore.
In length, and occurs in large shoals on the Atlantic coasts of Europe.
The sprat is one of the more important foodfishes on account of the immense numbers which are caught when the shoals approach the coasts.
The eastern or broad end is occupied by the town of Kronstadt, and shoals extend for a mile and a half from the western point of the island to the rock on which the Tolbaaken lighthouse is built.
The island thus divides the seaward approach to St Petersburg into two channels; that on the northern side is obstructed by shoals which extend across it from Kotlin to Lisynos on the Finnish mainland, and is only passable by vessels drawing less than 15 ft.
The second important embayment is the estuary of the Columbia river; but theoccurrence of shoals at the mouth decreases the use that might otherwise be made of the river by ocean-going vessels.
The isle is surrounded by shoals, and high-level and low-level lighthouses have been erected, the one at the north-west and the other at the north-east corner.
The navigable mileage of the Alabama rivers is 2000 m., but obstructions often prevent the formation of a continuous route, notably the "Muscle Shoals" of the Tennessee, extending from a point io m.
Long) is prevented by shoals and a 60-ft.
Owing to a dangerous bar at the mouth of the Magdalena the trade of the extensive territory tributary to that river, which is about 60 ho of that of the entire country, must pass in great part through Barranquilla and its seaport, making it the principal commercial centre of the republic. Savanilla was used as a seaport until about 1890, when shoals caused by drifting sands compelled a removal to Puerto Colombia, a short distance westward, where a steel pier, 4000 ft.
In length, but is shallow and abounds in shoals and sandbanks.
The passage north of Puna Island is known as the Morro channel, but its entrance is obstructed by shoals and it is considered dangerous for shipping.
The Cargados, Carayos or St Brandon islets, deeps and shoals, lie at the south end of the Nazareth Bank about 250 m.
So recently as about 1880 it discharged into the Gulf of Smyrna, but the shoals formed by its silt-laden waters were so obstructive to navigation that it was turned back into its old bed.
To the north-west of the volcanic island of Zebayir the depth is less than 500 fathoms; the bottom of the channel rises to the ioofathom line at Hanish Island (also volcanic), then shoals to 45 fathoms, and sinks again in about the latitude of Mokha in a narrow channel which curves westward round the island of Perim (depth 170 fathoms), to lose itself in the Indian Ocean.
Strabo mentions the existence here of a look-out tower for the shoals of tunny-fish.
As soon as the ice breaks up in the delta innumerable shoals of roach (Leuciscus rutilus) and trout (Luciotrutta leucichthys) rush up the river.