220 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Massachusetts Bay, as appears in the following 

 table : 



Water temperatures, Massachusetts Bay to Lurcher Shoal, 

 1920-1921 



Presumably the pollock of Georges and Browns 

 Banks and of outer Nova Scotian waters to the 

 eastward reproduce themselves there. But we 

 have no definite information in this regard. 



A few ripe fish are caught in the Massachusetts 

 Bay region as early as the last week in October, 

 and the first of November to the middle of Jan- 

 uary covers the most active production there, as 

 illustrated by the following table supplied by 

 C. G. Corliss, former Superintendent of the 

 hatchery, where many millions of -pollock eggs 

 were once hatched yearly. 



The first week of March is the latest that the gill 

 netters have reported any spawning fish. 



The pollock spawns considerably earlier in the 

 Gulf of Maine than in European waters, where 

 spawning does not begin until January, is at its 

 height in March, and continues into April. 



The Gulf of Maine pollock, like the cod and had- 

 dock, spawn in comparatively shoal waters. Thus 

 we have towed a considerable number of pollock 

 eggs over Stellwagen Bank where the water was 

 only 16 fathoms deep (on November 8, 1916) and 

 most of the ripe fish that supplied the Gloucester 

 hatchery with eggs were netted in depths of 25 to 

 50 fathoms. Probably few spawn deeper than 50 

 to 60 fathoms, and there is no evidence in egg 

 records, in captures of ripe fish, or in fishermen's re- 

 ports, that any pollock eggs are produced in the 



deep basins of the Gulf. In European waters, 

 however, this fish is described as breeding only in 

 depths greater than 75 fathoms. 



The gill netters have described it to us as spawn- 

 ing over hard bottom chiefly, though the pollock i9 

 not a ground fish at other seasons. 



The migrations of the young pollock in our 

 Gulf, from hatching until they appear on the 

 coast as yearlings, are of special interest because 

 of the probability that the great majority of all 

 the pollock that frequent the eastern coast of 

 Maine and the Bay of Fundy region are produced 

 elsewhere. Some of them may come from spawn- 

 ing grounds (as yet unmapped) off southern or 

 western Nova Scotia; our own observations throw 

 no direct light on this point. But what is known 

 of the general circulation of the Gulf in spring 

 and early summer suggests, rather, that the bulk 

 of them come from the spawning grounds on the 

 western side, south of Cape Elizabeth, having 

 circled around first southward, then eastward and 

 northeastward, and so finally to the Bay of 

 Fundy and to the east part of the Maine coast. 

 Others, hugging the coast more closely in their 

 involuntary journeyings, may follow past Cape 

 Cod and so westward, evidence of which is the 

 presence of an abundance of pollock fry in spring 

 at Woods Hole, for pollock are not known to 

 spawn in quantity anywhere west of the Cape 

 (p. 219). 



Strangely enough, we have caught no pollock 

 less than 8 or 9 inches long on the offshore banks 

 either on hook and line or in our tow nets, nor 

 have we seen any that had been trawled there. 

 Whether this is because the young are too nimble 

 to be taken in trawls, whether because they live 

 well off bottom, or whether because they are 

 scarce offshore, is not known. 



The larger pollock of our Gulf seem to wander 

 but little, for many that have been tagged by the 

 U. S. Bureau of Fisheries have been recaptured 

 within short distances of the localities where they 

 were marked, and after long periods of time. 

 And while a few of the marked fish are known to 

 have made considerable journeys eastward, (one, 

 for example, from Jeffreys Ledge to Sable Island), 

 instances of this sort have not been numerous 

 enough to suggest any mass movements. 



Pollock appear to be similarly stationary all 

 along the outer Nova Scotian coast, for they are 

 caught there throughout the fishing season. But 



