of the Fishery Board for Scotland. 



123 



was used. In the twelve months all the vessels showed an increased 

 gross catch with the use of the otter-trawl, compared with the 

 previous twelve months. 



The increased gross catch with the otter-trawl in the three months 

 thus amounted to 31 "8 per cent., and in the twelve months to 37*5 per 

 cent, the relative eificiency of the otter as comjmred with the beam- 

 trawl being 1-32 and r37 respectively. The twelve months comparison 

 is better, not only because the period is four times longer, but because 

 it embraces all the months in the year,* and it is remarkable that the 

 percentage of increase and the relative efficiency of the two nets 

 correspond exactly with the figures deduced by Mr. W. Gai'stang from 

 a comparison of the ^ross catches of steam ti'awlers in Scotland in the 

 years 1893-94, and 1896-97.t 



The detailed statistics show that the gross increase referred to was 

 made up entirely of round fishes. In the three months when the otter- 

 net was first used two of the vessels showed an increase in the quantity 

 of flatfishes taken, and three a decrease, while in the twelve months 

 following its introduction all the vessels exhibited a decreased c;\tch of 

 flatfishes, as shown by the following figures, in which round fishes 

 include cod, ling, saithe, haddock, whiting, hake, and gurnard, and flat- 

 fishes include turbot, brill, halibut, lemon soles, plaice, dabs, witches, 

 and mesrrims. 



* The otter-trawl was substituted for the beam-trawl in the various vessels in the fol- 

 lowing months:— No. I. May 1897 (headline, 95 feet) ; No. II. February 1897 ; No. III. 

 July 1S96 ; No. IV., November 1897 ; No. V., December 1896 (headline, 95 feet) ; the 

 three month.s on either side of the month named (and omitted) thus varied in the differ- 

 ent cases. 



\Journ. M.B.A., vi., 50. 



