Fishes of the Western North Atlantic 283 



waters, to return to more temperate coasts in spring, some of them to the eastern side 

 of the North Atlantic, others to the western side (for further details, see Meek, pj: 

 67-87). But Perley wrote as early as 1852 that this idea was "supposed to be wholly 

 imaginary," it being generally believed then "that the herring fattens in the depths 

 of the ocean, and approaches the shore in shoals merely for the purpose of depositing 

 its spawn" {104: 206). Successive and long continued studies at many hands have 

 since proven that in reality we are not dealing with any widespread mass migrations, 

 but with short-range movements (inshore and offshore) of local bodies of fish, each 

 with its own area of occurrence and each of which may include subpopulations that 

 spawn at different times of year, as Norman has pointed out. It is equally clear that the 

 ranges of the races of European fish overlap — highly probable at least that more or 

 less interchange is constantly taking place between adjacent races. 



However this may be, the basic migratory pattern, essentially the same for all of 

 them, may be conveniently divided into the three successive phases noted previously — 

 sardine, fat, and spawn. 



Those of the sardine stage, 45-200 mm long, tend to remain near their birth- 

 place. They probably spend the winters on the bottom in a few fathoms, appear in the 

 inshore waters of New England, New Brunswick, and Nova Scotia in the spring as 

 one- and two-year-old fish, and remain there through the summer and autumn. 

 How far they may journey during this period and in what direction depends chiefly 

 on the movements of the water. For example, every summer untold millions of sardines 

 congregate in the Passamaquoddy region at the entrance to the Bay of Fundy (p. 290), 

 and it is now known^' that the responsible factor is the prevailing movement shoreward 

 of the subsurface water in which the sardines are swimming; this shoreward flow is 

 motivated by the offshore movement of surface flow from tributary streams combined 

 with superficial offshore currents set up by the wind. Sardine-sized fish, in other 

 words, drift with the current much as do any planktonic animals, such as the euphausiid 

 shrimps and copepods on which they feed. In technical language, they are denatant, 

 which applies equally wherever young Atlantic Herring are produced. 



The fat stage consists of sexually immature fish about two years old and 1 90— 

 200 mm long that have accumulated a large amount of fat around the viscera and 

 among the body tissues. During the year's period that precedes their sexual maturity, 

 they disperse much more widely than do the sardines. Whether this wide scattering 

 is brought about wholly by transport of water movements or whether directive swim- 

 ming plays an important role remains a mystery. In either case they are encountered 

 anywhere and everywhere throughout the range of this species. In the Gulf of 

 Maine, for example, where more attention has been paid to the movements of these 

 fish than has been the case anywhere else in the western North Atlantic, the fat 

 stage has been encountered indifferently close to shore, as at the mouth of the Bay 

 of Fundy in the northeast, and offshore in the Massachusetts Bay region in the 



13. Studies carried out from the Atlantic Biological Station at St. Andrews, chiefly under Dr. A. G. Huntsman's 

 leadership (65:95, 96)- 



