Nesbit and Neville (1935) state: 



In this very deep water, the bottom temperatures 

 are very low the year round. Inshore of this area of 

 cold water is a zone of water between the 40 and 150- 

 fathom depths warmed from surface to bottom by the 

 Gulf Stream throughout the winter. Thus, there is a 

 narrow band of relatively warm bottom water present 

 throughout all winters (of which we have record) follow- 

 ing in general the 100-fathom line extending from 

 abreast of Cape Hatteras to at least abreast of Cape 

 May and even continuing to abreast of Cape Cod and 

 along the southern edge of Georges Bank. In contrast 

 to this band of water which is warm both in winter and 

 in summer, the water covering the wide inshore sub- 

 merged plain out to about the40-fathom depth is subject 

 to great seasonal changes, for here the temperatures 

 are high in summer, but in winter the water is chiUed 

 to a greater or less degree from surface to bottom. 



This cooling begins in the fall and takes 

 place from inshore to offshore. In reference 

 to this, Bigelow (1933) states: 



In late autumn and early winter, cooling proceeds 

 most rapidly near the land. By mid-December the 

 water is coldest inshore, surface to bottom; the thermal 

 pattern is of the winter type with the isotherms (lines 

 of equal temperature) paralleling the coastal trend at 

 all depths; and a cold inshore boundary has been re- 

 established to the bottom water warmer than 8°-9 C. 

 (46°-48° F.) that washes the edge of the continent. By 

 the middle of the month, mean temperatures are about 

 5°-80 c. (410-46° F.) along shore, and lO^-lS^ C. 

 (50° -55° F.) along the outer edge of the shelf (100 

 fathom line) . . . and with vertical equalization so 

 nearly complete that the difference between surface 

 and bottom is in most cases less than 0.5° C. (0.9° F.) 

 at given stations. 



Cooling proceeds through January until, by the end 

 of the month, the temperature, surface to bottom, has 

 ordinarily fallen below 50-6° C.(41°-43° F.) all along 

 the coast; to 8°-9° C. (460-48° F.) midway out on the 

 shelf; but is still IOO-I20 C. (50°-54O F.) along the 

 outer edge of the latter. And cooling continues through 

 the later winter until the minimum for the year is 

 reached late in February, or early in March 



No thermal ev 

 spread influx of 

 (Chesapeake Bay 

 Cape Hatteras) of 

 oceanic water of 

 onto the shelf of 

 sometimes been 

 grounds. 



idence has been found of any wide- 

 warm coastal water into the region 

 to Cape Cod) from the south (below 

 any floodings of the surface with pure 

 high temperature, nor of upsweUings 

 the cold abyssal water, such as have 

 postulated in the past on theoretic 



The amount of chilling on the shelf between 

 Cape Hatteras and Cape May has differed 

 considerably in each of the past five winters 



(1931-35). The extent of the zone of rela- 

 tively warm water tolerated by the species 

 has also differed in one winter compared to 

 another winter, for obviously the width of this 

 zone will be less during a cold winter than 

 during a warm winter. It follows, therefore, 

 that in some years the fish have been more 

 or less confined and, hence, concentrated in 

 a relatively small area, while in other years 

 when cooling has been relatively less, the 

 zone of warm water has extended over a wider 

 area, and the fish are free to move over a 

 larger expanse of sea bottom. This has been 

 clearly demonstrated by comparing the lo- 

 calities of best fishing with the zone of water 

 warmer than 45° F., the latter being assumed 

 a reasonable low temperature limit, but by no 

 means the absolute limit tolerated by the fish 

 (figs. 10 and 11). 



During the winter of 1931, the water over 

 the entire shelf was chilled, and by the early 

 part of March the zone of bottom water warmer 

 than 45° F. was confined to a narrow band 

 lying beyond the 40-fathom line. Scup, sea 

 bass, and fluke were confined to water out 

 near the edge of the shelf and to depths 

 greater than 40 fathoms where the water 

 was 45° F. or warmer. In the following 

 winter (1932), the inshore shoal water did not 

 cool to such low temperatures as in the previ- 

 ous winter, and relatively warm water was 

 present over a much greater extent of sea 

 bottom. In that winter, scup, sea bass, and 

 fluke were not driven as far offshore by 

 water colder than 45° F., and the best catches 

 were made much farther inshore and in water 

 more shoal than in the winter of 1931. In the 

 next winter (1933), water temperature con- 

 ditions were about the same as in the previous 

 winter (1932), and the best fishing was also 

 in about the same location. 



Nesbit and Neville (1935) state: 



In the past winter (1934) there was a combination 

 of the conditions of the three previous winters. The 

 early part of the season (January) the water was rela- 

 tively warm, resembling 1932 and 1933, but the latter 

 part (March) the water was relatively cool, resembling 

 1931. Although air temperatures were low in January, 

 there had not been time for any considerable cooling 

 of the water, for the zone having bottom temperatures 

 warmer than 45° F. apparently stUJ extended over 

 about the same general area as in the previous two 



39 



