126 



temperatures at this time of year). According to the Bulletin for May of the same year 

 the surface temperature for this month was everywhere at most only 1° higher, and we 

 thus have the approximate temperatures at which most of the gadoids dealt with here 

 spawn. For the rest, the numbers show great uniformity throughout the year; even on 

 the surface the yearly fluctuation in the temperature is but small, and deeper 

 down naturally even less; this can be seen distinctly from the two Irish quarterly stations 

 on the southern part of the west coast and the western part of the south coast; the 

 observations at these are given in the following (from the Bulletin). 



Temperatures in 1906 

 Off the Blaskets, ca. 52° 02' N., 10°55'W.; depth ca. 145 meters. 



Depth 



(meters) 







55 



110 



Off Fastnet, ca. 51° 14' N., 9° 43' W., depth ca. 110 meters. 



StC) ^«^- »l^y ^"g- Nov. 



9-7° 9-2° 13-5° 11-95° 



55 9-5° , 9-34° 9-15° 9-82° 



106 9-9° ' 9-32° 9-21° 9.87° 



These two stations show with great distinctness that at a depth of ca. 50 meters 

 there is but little difference at the different periods of the year, and that at a depth of 

 ca. 100 meters the difference is not more than ^2° — 1°. Further, the observations show 

 that in the months of Feb. — May, i. e. during the spawning time of most of the gadoids, 

 the temperature from the surface down to at least ca. 100 meters is practically the same, 



That there is on the whole no very great difference in temperature in spring and 

 winter between the northern and southern parts of the west coast of the British Isles is 

 seen from the Table p. 115 as well as from the data below for Scotland (LochFyne ca. 56° 

 N. L.)i and S.W. Ireland (Fastnet Rock, 51° 23' N. L.). 



' Attention may be drawn here to the relatively high temperatures in the winter and spring months, 

 e. g. about 9° in January. I may say that I find in this the explanation why the distinctly southern 

 species G. luscus spawns here in no inconsiderable numbers. 



'' The temperatures are taken from Williamson's paper in the 17th Annual Report Fishery Board 

 for Scotland, p. 130, 1899, and refer to the year 1898. 



'' The temperatures given are the averages of daily observations in the year 1904, published in 

 "Fisheries, Ireland, Soi. luvest., 1904, VI (1906)". 



