668 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



merely along our whole southern coast, but likewise on the western 

 coastj at least as far as the heights of Bergen, and during the summer 

 give employment to a large number of fishermen, who during a favorable 

 season make a right good living. These fisheries are at present chiefly 

 carried on by means of floating nets from May till the middle of July, 

 and generally at a considernble distance from the coast, sometimes 6-8 

 (Norwegian) miles. 



As has been the case with several of our well-known fish, many errone- 

 ous notions have likewise prevailed with regard to the nature and the 

 migrations of the mackerel. Some of these notions are even entertained 

 at the present day, and are brought forward in ichthyological works. 

 Although it is of course impossible for me, after having studied the 

 nature of the mackerel only for a comparatively short time, to pronounce 

 a definite opinion on every point in its natural history, I nevertheless 

 feel competent to correct some of the erroneous notions which have been 

 entertained hitherto, and through direct observations to supplement our 

 knowledge of this fish. 



The first question which presents itself is this: " Where is the proper 

 home of the mackerel f It is well known that the grown mackerel like 

 the spring herring and the codfish only visits our coasts during a certain 

 season of the year, and then disappears without leaving the slightest 

 clew as to its whereabouts. Where does it go, and where does it stay 

 during the remaining portion of the year ? The opinion which at present 

 is most prevalent among zoologists is, that the mackerel stay in the 

 great depths immediately outside the coast, an opinion which has also 

 been advanced with regard to the spring herring, but which — in my 

 report for 1873 — I have endeavored to prove is erroneous. 



As far as the mackerel is concerned another erroneous opinion is very 

 widely spread, viz, that while living in the deep it is blind and lies at 

 the bottom in a sort of torpor. Although this is highly improbable, we 

 still find it mentioned in many ichthyological works ; and so far, at least, 

 this opinion has not been seriously refuted anywhere. The fishermen, 

 who of course were the first to advance this opinion, are thoroughly 

 convinced of its correctness. They say that experience has taught them 

 to believe it. They maintain that in the beginning of the fisheries the 

 mackerel enters the nets much easier than later in the season ; and this, 

 they say, can only be explained by the circumstance that the mackerel 

 cannot see very well, while later when it has got its full sight, it is more 

 cautious. They say that any one can see the opaque skin which covers 

 the eyes of the mackerel, and that its disappearance and growth may 

 be observed during the summer. With the first mackerel which are 

 caught early in spring, this skin covers the greater portion of the eye, 

 with the exception of the middle portion. Later in summer the skin 

 becomes more transparent and recedes from the middle of the eye ; 

 while toward fall when the mackerel is about to return to the deep, it 

 begins to grow and become more opaque. 



