456 



RErORT ON TRAWLING AND OTHER INVESTIGATIONS 



increase during 1902 an exceptional feature, or merely the prelude of a 

 return to more normal conditions ? 



There is no available means of answering these questions except by 

 a comparison with the results contained in Mr. Holt's previous report 

 on the Association's work in the bays during 1895 to 1898, fron) which 

 the following table has been prepared. 



Table VI., skoicing the Catch 2)er Hour and the Percentage Frequency 

 of Plaice of different sizes in Start Bay during 1895-1897, based on 

 the records of the "Thistle" and "Busy Bee" (comjnlcd from, Mr. 



Holfs report). 



Season. 



March, '06, '97 . 



May, June, '97 . 

 July, '98 . 

 Oct., Dec, '95, '96 



Vessel. 



(Thistle, 3 hauls \ 



\ Busy Bee, 1 haul / 



Busy Bee, 4 hauls 



,, 2 hauls 



Thistle, 6 hauls 



The chief difficulty in a comparison with these records arises from 

 the fact that the previous investigations of the Association were carried 

 out by means of two boats, the smack Thistle and the small steam yacht 

 Busy Bcc, which were of different catching power compared with one 

 another as well as with the Oithona. It will be seen that the work in the 

 winter and autumn seasons during the previous investigations was mostly 

 carried out by the Thistle, and during the summer by the Busy Bee. 



It will also be seen that the average catch of the Busy Bee in spring 

 and summer was so markedly inferior to the catch of the Thistle in 

 autumn and winter that no conclusions can be drawn from the figures 

 as they stand in regard to the seasonal changes which formerly took 

 place in the abundance of plaice in the bay ; but at least two methods 

 of comparison with the records of the Oithona are open to us, viz. 

 (1) the percentage distribution of plaice of different sizes can be com- 

 pared with the corresponding figures for the Oithona's work, and (2) the 

 average hourly catch of the Biisy Bee may be assumed to have been not 

 greater than that of the Oithona, since the Btisy Bee was a somewhat 

 smaller vessel and carried a smaller trawl. 



If we take the latter point first into consideration, we may observe 

 that whereas in the spring and summer seasons the Busy Bee made, in 

 Start Uay, an average hourly catch of 16 and 15 plaice respectively, the 

 Oithona, during the corresponding seasons, caught 18 plaice per hour in 

 the spring, from 18 to 19 per hour in the summer of 1901, and from 23 

 to 28 per hour in the summer of 1902. The total catch, as was to be 

 expected, was therefore higher in the case of the Oithona than in that 

 of the Busy Bee. Nevertheless, on turning to the table again, we see 

 that during the spring quarter the Busy Bee caught a far higher average 



