404 



Part III. — Twefttieth Annual Report 



In the Jeep water off the Shetlands the young haddocks under one year 

 of age were obtained in August, September, and October 1900, Decenjber 

 1901, and March 1902, and the same series, then over one year old, were 

 taken in May 1901. The various months are not in sequence, and the 

 ranges and averages cannot therefore be compared with strict accuracy, 

 since the growth in one year, or at a given period of one year, may not 

 correspond with another year. The places, moreover, where the haddocks 

 were caught were sometimes a considerable distance apart {see p. 407). 

 The variation in this respect is, however, probably not so great as to 

 impair the value of comparison. The particulars of the series are given 

 in the Table on p. 408). 



On 31st August-4th (September, 263 ranging from 61 to 148 mm. had 

 an average size of 88-4 mm., or 3| inches; on 16th-19th October 235 ranged 

 from 82 to 167 mm., the average being 119*2 mm., or 4i^ inches ; on 11th 

 December 265 ranged from 91 to 185 mm., the mean being 135-4 mm., 

 or 5^ inches; and on 10th March (1902) 36 ranged from 153 to 205 mm., 

 with an average size of 173*0 mm., or 6j-| inches. Some of these ranges 

 and averages require slight correction, and Ihe range for March (52 mm.) 

 is obviously much too small; it ought to be from about 120 to 210 mm., 

 and the average should be 8 or 10 mm. lower. 



In any case the contrast in size between these young deep-sea haddocks 

 and those of Aberdeen Bay at corresponding dates is marked. At the 

 beginning of September they are more than two inches smaller in the deep 

 water, an inferiority no doubt largely due, as indicated also in the 

 whiting, to the slower rate of growth in the lower summer temperature 

 prevailing there as well as to a later spawning period. But this inferiority 

 is gradually diminished during the following winter and spring, so that 

 while the September average differs by about 53 mm. the December 

 average differs by about 46 mm., and in May the difference is reduced 

 to something like ten millimetres. {See Curves, Plate XXI.). 



It is clear that the young haddocks described above are fish which were 

 hatched at the last spawning season, and not fish of the previous year — 

 that is to say, that they are only some months old. We know that 

 growth in inshore waters is more rapid before the end of July than 



