400 BULLETIIv" OF THE BUKEAU OF FISHEEIES 



season that few are taken inshore in the Massachusetts Bay region during July and 

 August, though they do not travel far or sink deep, for good fares of large fish 2 to 3 

 feet long are brought in by line fishermen from Jeffreys Ledge throughout the 

 summer, most of them caught some distance above bottom. 



North of the Isles of Shoals pollock are more commonly seen on the surface 

 during the hot months. For example, small boats from Cape Porpoise and neigh- 

 boring ports were doing well drailing during July and early August, 1922, and 

 great numbers of large pollock are caught all summer in the cool surface waters at 

 the mouth of the Bay of Fimdy in ripplings and tide rips, while middle-sized fish 

 swarm for some distance up the bay in the strong tideways on both sides — for 

 instance, about Eastport and in Digby Gut. However, pollock decrease in munbers 

 passing up the bay and fail altogether at its extreme head. 



When the breeding season draws on in autumn large pollock again congregate 

 in abundance along the coast line from Cape Porpoise to Cape Ann and off Massa- 

 chusets Bay, and it is in late autumn and winter that the gill-netters make their 

 largest catches there. But few are caught there after spawning until the following 

 April, showing that the spent fish do not winter on particular grounds but scatter 

 and wander to and fro in search of food. 



On Georges Bank and the other offshore fishing grounds pollock are caught all 

 through the year, with no greater seasonal fluctuation in tho landings than might 

 result from the various vicissitudes of chance, weather, and the market. 



Although its spawning and feeding journeys may lead the pollock right across 

 the Gulf of Maine it is not a "migratory" fish there in the sense in which that term 

 is popidarly understood, but one of the most characteristic residents. It becomes 

 migratory west of Cape Cod, however, because the bodies of fish that appear off 

 southern New England in autumn and spring vanish thence when the water warms 

 to about 60° and 65°, all probably withdrawing to the eastward to Nantucket 

 Shoals and past Cape Cod to pass the summer, and most of them breeding in the 

 Gulf of Maine. 



Habits and food. — The pollock is an active wandering fish, living at any level 

 between bottom and surface, often schooling like the mackerel, and sometimes gath- 

 ering in bodies so large that it is on record that a purse seiner once took 60,000 out 

 of one school at a single set. It is predaceous, feeding chiefly on small fish and on 

 pelagic crustaceans — among the latter most often on the large pelagic shrimplike 

 euphausiids, and it is the local presence or absence of prey that govei'ns the move- 

 ments of the larger fish and their schooling. 



It is a commonplace that pollock destroy great quantities of small herring, 

 launce, young cod, young haddock, young hake, silver hake, and other small fish 

 in the Gulf of Maine just as they do on the other side of the Atlantic, and, although 

 we can not offer exact particulars of this, pollock chasing schools of herring are a 

 familiar sight,"" while fish of 1 to 1}^ pounds commonly run up estuaries in pursuit 

 of smelt in autumn. Haddock or other larvte liberated in harbors are always in 

 danger of being snapped up by the young pollock so plentiful in such situations. 



" Sars (Report of the Commissioner of Fish and Fislieries, 1877 (1879), p. 619-620) has given a graphic account of pollock 

 rounding up schools of launce and young cod in Norwegian waters. 



