FISHES OF THE GULF OF MAINE 



325 



characterized as "huge amounts." He also reports 

 "a large body of fish" off Montauk in mid- 

 February of 1950. Schools of "mackerel" have 

 also been reported as sighted at the surface on 

 several occasions in winter, but none of these seem 

 to have been brought in. 



Direct evidence carries us only this far. But 

 the indirect evidence of temperature is suggestive. 

 Thus, the Gulf of St. Lawrence (where ice some- 

 times forms), outer Nova Scotian waters, and the 

 upper 50 fathoms or so within the Gulf of Maine 

 which chill to 35°-39° F. (2°-4° C.) or colder, are 

 all too cold by late winter for mackerel, which are 

 never encountered in commercial quantities in 

 temperatures lower than about 45° F. (7° C.). 

 In most years this applies equally to the inner part 

 of the continental shelf as a whole, southward as 

 far as northern Virginia, for the water usually cools 

 there to 37°-40° F. (3°-4° C.) at the time of the 

 winter minimum. But the mackerel need only 

 move out to the so-called warm zone at the outer 

 edge of the shelf to find a more suitable environ- 

 ment, for the bottom water there is warmer than 

 44°-46° F. (7°-8° C.) the year round as far north 

 and east as the central part of Georges Bank, and 

 about 41° F. (5° C.) along outer Nova Scotia. 



Available evidence thus supports Sette's 33 con- 

 clusion that the bulk of the American mackerel 

 winter on the outer edge of the continental shelf 

 from the offing of northern North Carolina to the 

 mid-length of Georges Bank, 30 to 100 miles off 

 shore according to location, in depths of perhaps 

 50 to 100 fathoms. The few that are caught 

 closer to land and in shoaler water in winter either 

 represent the inshore fringe of the main population, 

 or they are strays. Perhaps some winter off Nova 

 Scotia as far east as Sable Island Bank. And it 

 would not be astonishing should it prove that some 

 winter in the deep eastern trough of the Gulf of 

 Maine, where the temperature of the bottom 

 water, at depths greater than 75 fathoms or so, 

 does not fall below about 41° F. (5° C.). A few 

 mackerel have, in fact, been caught on cod lines in 

 deep water off Grand Manan in winter, 34 while 

 two were found among kelp near Yarmouth, Nova 

 Scotia, on December 28, in 1878. 35 



» Fish. Bull. 49, U. S. Fish and Wildlife Service, vol. 51, Fish. Bull. 49, 

 1950, p. 261. 



« Collins, Kept. U. S. Comm. Fish (1882) 1883, p. 273. 



« Ooode, Collins, Earll, and Clark, Rept. U. S. Comm. Fish. (1881) 1884, 

 p. 98; cited from the Yarmouth, Nova Scotia, Herald, January 2, 1879. 



Sette 38 has pointed out, however, that some 

 other factor besides temperature must have to do 

 with the wintering habits of the mackerel, for they 

 disappear as completely from the surface and from 

 inshore in the southern part of their range as they 

 do in the northern even in very warm years such 

 as 1932, when the water (surface to bottom) was 

 warmer than 45°-46° F. (7°-8° C.), from New 

 Jersey southward, even at the end of the winter. 

 On the other hand, the event (probably ab- 

 normally low temperature) that was so destructive 

 to the tilefish in March, 1882 (p. 429), did not affect 

 such of the mackerel as were wintering on the 

 fcilefish grounds, for they reappeared that summer 

 in normal numbers, a point to which Sette 37 has 

 called attention already. 



Two additional facts which support the view 

 that our mackerel do not travel very far in winter 

 are (a) no mackerel, young or old, have ever been 

 taken outside the edge of the continent, or any- 

 where on the high seas far from land for that 

 matter; (6) their reappearance in spring takes place 

 so nearly simultaneously along some hundreds of 

 miles of coastline that they can hardly have come 

 from any great distance. 



Thus time and increased knowledge have corro- 

 borated the view of Captain Atwood and of Perley, 

 of more than half a century ago that mackerel 

 winter offshore in deep water and northward from 

 the latitude of Virginia, not in the far south nor 

 out in the surface waters of the warm parts of the 

 Atlantic. 



The winter home of the American mackerel 

 appears to correspond rather closely to that of 

 the mackerel of British seas, some of which winter 

 on the deep northern slope of the North Sea, 

 some in the deeper parts of the English Channel, 

 and many on the outer edge of the continental 

 shelf southwest of Ireland, mostly deeper than 

 60 fathoms. 38 



The failure of the otter trawlers to take com- 

 mercial quantities of mackerel off Chesapeake 

 Bay in winter when they fish there intensively, 

 leads Sette 39 to conclude that our mackerel 



» Fish. Bull. U. S. Fish and Wildlife Service, vol. 51, Fish. Bull. 49, 1950, 

 p. 527. 



« Sette, Fish. Bull. U. S. Fish and Wildlife Service, vol. 51, Bull. 49, 1950, 

 p. 257, Footnote 3. 



" Ehrenbaum (Rapp. et Proc.-Verb. Cons. Perm. Internat. Explor. Mer, 

 vol. 18, 1914) summarizes what was known of the life history of the European 

 mackerel up to that time. And Steven (Jour. Marine Biol. Assoc. United 

 Kingdom, vol. 27, 1948, pp. 517-539) has recently outlined the chief winter- 

 ing grounds. 



» Fish. Bull. U. S. Fish and Wildlife Service, vol. 51, Bull. 49, 1950, p. 261. 



