XXX REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



against the Decessity for any protection of the fisheries from disturbance 

 during the spawning-season -, namely, for instance, that should Massachu- 

 setts pass laws for their i)rotection, it would be of no avail so long as 

 Rhode Island and Connecticut failed to do the same. The practical re. 

 suit of protection on the one hand and of license on the other, probably 

 would be, that after a few years' interval fish would be as abundant as 

 ever on the Massachusetts coast, and would be almost exhausted on those 

 of the adjacent States, and an important market would be furnished to 

 the Massachusetts fishermen outside of the limits of their own State. 



Another fallacy, which vitiates much otherwise sound argument on: 

 the question of jjrotection, is in confounding regular shore-fish, that 

 come in from the deep seas to the coast to spawn, with the outside fish 

 that come and go with more or less irregularity, and usually feed and 

 swim near the surface. In the one category we may enumerate the 

 porgies or scup, tautog or black-fish, and the sea-bass; while the other 

 includes such fish as the sea herring, blue-fish, mackerel, Spanish mack- 

 erel, and some others. The occurrence of the latter group is, to a large 

 extent, determined by the presence of the former. Should the first 

 mentioned be decreased materially in number, it becomes necessary for 

 their pursuers to seek other waters for their proper supply of food. The 

 case of the cod, that feeds largely upon ground-fish, as well as upon the 

 more surface-loving herring, is another instance in which the scarcity or 

 abundance of one fish is influenced by that of others. 



It was formerly supposed that certain fish, as the herring, the shad, 

 and the alewives, with others of like habits, prosecuted an extensive 

 migration along the shores of the ocean, covering, sometimes, thousands of 

 miles in the sweep of their travels -, and much eloquent writing has been 

 expended by such authors as Pennant and others in defining the starting- 

 point and terminus, as well as the intermediate stages of the voyage. 

 The shad, too, which, as is well known, occupies all the rivers of the Atlan- 

 tic coast from Florida to the Gulf of Saint Lawrence, was thought to begin 

 its course in the West Indies, and in an immense body, which, going- 

 northward, sent a detachment to occupy each fresh- water stream as it 

 was reached, the last remnant of the band finally passing up the Saint 

 Lawrence, and there closing the course. We now, however, have much 

 reason to think that in the case of the herring, the shad, the alewife, 

 and the salmon, the journey is simply from the mouths of the rivers by 

 the nearest deep gully or trough to the outer sea, and that the appear- 

 ance of the fish in the mouths of the rivers along the coast, at succes- 

 sive intervals, from early spring in the South to near midsummer in the 

 North, is simply due to their taking up their line of march, at successive 

 epochs, from the open sea to the river they had left during a previous 

 season, induced by the stimulus of a definite temperature, which, of 

 course, would be successively attained at later and later dates, as the 

 distance northward increased. 



The principle may safely be considered as established that line-fish- 



