66 SALMONID^ OP BRITAIN. 



The migrations of the salmon from the sea towards inland fresh waters are, 

 broadly speaking, of two kinds : first, what may be generally described as the 

 great autumn and winter ones, for the purpose of spawning; and secondhj, much 

 more irregular ascents, consisting of a few or many tish, occurring throughout the 

 year, or restricted to certain months. This inquiry would embrace several con- 

 siderations, such as the following : — How do salmon return from the sea to our 

 coasts ? How do they enter and continue in estuaries prior to their ascent into 

 the stream ? How do they ascend rivers ? How do they return to the sea ? 



As a general rule, as I have observed upon under the head of '• early and late 

 salmon rivers," these fish migi^ate towards rivers sooner from cold seas, as the 

 German Ocean on the east coast of the British Isles, than they do along the west 

 coast, presumably because the Atlantic is warmer than the Clerman Ocean ; while 

 among the latest rivers they ascend are those of Devonshire and Cornwall, where 

 the temperature of the sea is the highest. 



With the object of attaining the estuaries or mouths of rivers up which they 

 purpose ascending, salmon in small assemblages or schools keep along the shore, 

 only a short distance from land, swimming rather high in the water, and betraying 

 their presence by occasionally leaping out of the sea as if they were endeavouring 

 to reconnoitre their way, or else they throw oif a ripple in a calm as they move 

 along the surface; while, as Mr. Sinclair of Donegal remarked (FielJ, March 

 29th, 1884), their tracks are as well known as those of cattle returniiig to the farm- 

 yard. Mr. D. Mackenzie in his Salmon Fisheries of Scotland, 18G0, page 43, has 

 also observed that along the coasts of Scotland salmon shoals pass a short distance 

 from the land, and "when a shoal meets with a stake net some of the fish are 

 caught in the ti^aps or cruives, or what are called its chambers, others start off; 

 in short, the shoal is broken and dispersed. The scattered fish, however, always 

 guided by their instincts, gather in again to the land, singly or in groups, and 

 continue their course with the tides, until they meet with another similar engine, 

 when the same capture and dispersion is repeated." While packs of seals, 

 poi-poises, grampuses, and other enemies have been observed to deter salmon from 

 entering rivers, and also to break up and scatter the shoals of fish. 



Salmon appear to possess a homeing instinct which induces them to endeavour 

 to return to the river where they were originally reared,* but instances are 

 occeisionally brought to notice when such could not have been the case. Thus 

 almost yearly we hear of a grilse or of a salmon being captui'ed off the mouth of 

 the Thames or Medway, sometimes even attempting to ascend, but from which 

 localities all these fish have long since been desti-oyed; consequently they could 

 not be descended from eggs hatched in those rivers. 



'at)^ 



obstruction to ascent ; remove that obstruction or pass the breeding fish over it early in the 

 breeding season, the young are earlier reared, and the breeders return sooner into condition than 

 had they been left to wait to a later period before spawning. This and other examples which I 

 have adduced, go to prove that artificial causes may convert an early breeding into a late breeding 

 river ; that alter the conditions, and the fish may again breed in the earlier months, but more 

 evidence is requisite to show the result of this on the early ascending fish. 



3Ir. Francis Francis, having remarked: "The Erne and the Bundrowse are only a few miles 

 apart ; their capabilities are very similar, both have large lakes for shelter, yet one gives fish in 

 February and the other not till May," the Editor of The Field observed, " Where there are heavy 

 spring runs which are left solely to the rod and never netted, those runs keep up in almost 

 undiminished numbers, but as soon as the nets are brought to bear, they sooner or later die out 

 altogether." 



* Buckland recorded how a friend of his, who owned a well-known island on the west coast of 

 Scotland, netted a certain pool in his fishery, and out of a number of fish which he captured he 

 marked twenty or thirty. He then put them on board his yacht, where they were kept alive, and 

 he sailed with them almost round his island, then up a creek to the mouth of a river, and turned 

 them into a lake about half a mile from the source of the stream from which they had been 

 originally captured, but with which it was in no way connected, the two rising from different 

 watersheds. It was as though the salmon had been carried from one heel of an enormous horse- 

 shoe round to the other heel, and then taken right into the middle of the horse-shoe, and there 

 let loose. During the same season some of these marked fish wer'e caught in or near their own 

 pool, to do which they must have come back a circuit of at least forty miles, and passed by six or 

 seven tributaries. 



Mr. P, Milne Home, when writing ab ut the Tweed, observed that marked fish from that river 



