IN THE BAYS ON THE SOUTH-EAST COAST OF DEVON. 



457 



quantity of small plaice per hour than did the OitJiona, viz. 14 plaice 

 per hour helow 12 inches in length, as against only 5 per hour in the 

 case of the Oithona. Again, during July the Busy Bee caught an average 

 of 1!2 fish per hour below 12 inches in length, whereas in the summer 

 quarter of 1901 the Oithona caught only 6 per hour. The conclusion 

 appears to be that the small plaice below 12 inches in length were 

 abnormally scarce in Start Bay during the summer of 1901 ; and the 

 records show that this abnormal scarcity continued until the corre- 

 sponding season of the following year. 



We have already seen that in the summer of 1902 the Oithona caught 

 a far higher number of immature medium-sized fish than in the corre- 

 sponding season of the previous year. In Start Bay the average catch 

 of these immature fish was from 13 to 16 per hour. For this bay, 

 therefore, we may conclude that the marked increase in the small plaice 

 during the summer of 1902 was not in itself an abnormal feature, but 

 was rather a sign of the resumption by the bay of its normal character- 

 istics, the scarcity of the small fish during the previous year having 

 been an exceptional phenomenon. 



The marking experiments, to be described below, give good ground 

 for believing that the actual increase in numbers of the medium-sized 

 plaice during the summer of 1902 was due to immigration from Teign- 

 mouth and Tor bays. There is also no evidence that any material 

 proportion of the plaice of this size in Start Bay were derived by growth 

 from the small stock of small plaice (below 8 ins.) previously in the bay. 



The explanation of the scarcity of the small plaice during 1901 and 

 the earlier half of 1902 is dealt with at a later stage (pp. 472 and 474) ; 

 but it is worthy of note that the phenomena described in the case of 

 the plaice were closely paralleled by changes which took place during 

 the same period in the abundance of small dabs. 



Table VII., shoiving,for Start 

 and the Catch ijer Hour 

 Marketahle Fish for each 



Seasou. 

 1901. 

 July, August 

 September 

 October 

 November . 

 December . 



1902. 

 January, February 

 April, May, June 

 July, August 

 October 



Totals 



Bay, the total number of Dabs measured, 

 and Percentage Frequency of Small and 

 Monthly or Quarterly Period. 



