MIGRATIONS OF COD 
71 
no influence on the migration of Nantucket cod, because they are always present 
all along our coast. 
Cod will eat any fish that they can catch, especially the small silvery species 
that travel in dense schools, and so are easily caught. The most important of these 
are capelin (Mallotus), herring (Clupea), and sand eels (Ammodytes). 
Capelin, of course, are restricted to arctic and subarctic regions and hardly 
extend south to Maine along our coast. But it is of interest to note that in the far 
north cod pursue capelin for long distances, feeding voraciously upon them. This 
occurs regularly off Labrador and Greenland and also off the Finmark and Murman 
coasts, as noted by Hjort (1914, p. 113). 
Cod often feed on herring, both small and large, and there is evidence that they 
pursue this food, at least for short distances. But Clupea are not particularly 
plentiful off the southern coast of Cape Cod, while to the westward of Montauk 
Point they are relatively scarce, and hence could hardly induce the cod’s migration 
into that region. 
The sand eel (Ammodytes) is the only one of the really important fish foods of 
the cod that is found in abundance on Nantucket Shoals and on the wintering grounds 
to the westward. But although the season when sand eels are abundant alongshore, 
west of Massachusetts, coincides with the season when cod are present there, we have 
no proof that cod are induced westward in order to feed upon them. This is made 
apparent by the fact that although Ammodytes is important to the cod to the westward 
of the shoals, as well as throughout most of the cod’s range, the food that must be 
depended upon there from day to day is the same sort as on all suitable bottoms off 
the New England coast, namely, crabs, shrimps, mollusks, brittle stars, worms, and 
occasional fishes of various species. Thus there is no basis for explaining this as a 
feeding migration. 
Competition for food between the cod and other fishes on Nantucket Shoals and the 
wintering ground to the westward. — It would seem that ordinarily cod were given 
relatively little serious competition for their food supply by other species of fish, 
particularly on Nantucket Shoals, for in this region only the haddock and the pollock, 
taken both from the point of size and of abundance, can be considered at all of im- 
portance in this respect. But as haddock eat chiefly the smaller crustaceans and 
mollusks, of a size generally disdained by the cod, it seems obvious that neither fish 
competes very seriously for the other’s food supply. The same can be said with 
respect to the pollock, for the latter feeds largely on squid and fish and, on Nantucket 
Shoals at least, eats very sparingly of the larger crustaceans which make up the 
bulk of the cod’s food. 
To the westward of Nantucket Shoals, excepting possibly the Rhode Island 
region, neither the haddock nor the pollock are sufficiently plentiful to affect the 
cod’s food supply. But in this westward region other species occur abundantly 
that are rarely found on the shoals, including the sea bass (Centropristes), the tautog 
(Tautoga) and the summer flounder (Paralichthys). It so happens that throughout 
the summer these species occupy the same rocky bottoms, wrecks, etc., that are 
inhabited by some of the cod during the winter, but this alternative occupation of 
the grounds goes on year after year, so it is apparent that neither body of fish exhausts 
the other’s food supply. Even if the summer fish did reduce considerably the food 
supply on the rough bottoms, it remains that much the larger part of the schools of 
cod distribute themselves over sandy, shelly, and gravelly bottoms whose area far 
exceeds that of the rocky bottom and whose food supply is scarcely disturbed by the 
