IS 



Part TIL- — Twenty-fourth Annual Report 



food, &c, while at the same time collections of floating organisms, or 

 plankton, are obtained. The employment of commercial trawlers for this 

 purpose is associated with certain disadvantages, particularly from the 

 point of view of comfort; but as the trawling work is carried on 

 precisely as it is when fishing for market purposes, opportunities are 

 afforded for various observations bearing on this method of fishing, as, 

 for example, the proportion of marketable and unmarketable fishes which 

 are taken, the influence of the size of the mesh on the size of the fish 

 caught, &c. The expense, moreover, is comparatively slight, as no charge 

 is made for the use of the vessels, which are also available for procuring 

 supplies of adult living plaice for the hatchery, without cost. 



On some of the occasions the records of the catches on board the 

 trawlers w r ere made by Dr. Williamson. 



I. 



The first of the trawlings was made in the Moray Firth and Aberdeen 

 Bay from the 6th to the 11th February, the steam-trawler "Loch 

 Lyddoch" being employed; rather heavy weather was encountered 

 during the latter part of the trip. The places visited in the Moray Firth 

 were Burgh ead Bay and the grounds off it, the grounds in deeper water 

 to the east of the Suters of Cromarty, and the Dornoch Firth. A gale 

 which sprang up, with a heavy sea, prevented the vessel from visiting 

 Smith Bank and the grounds off the Caithness coast, as was intended. 



The first hauls were made in Burghead Bay in the afternoon of 6th 

 February, the wind when the work commenced being from the westwards 

 and light. A drag in from about 5 to 12 fathoms for four hours, 

 and therefore somewhat close in, yielded a total of 596 fish, of which 511 

 were marketable and 85 unmarketable. The greater part of the market- 

 able catch consisted of plaice, and witches were fairly numerous. The 

 plaice numbered 292, all of them marketable, and most of them medium 

 and small, only 1 large plaice being taken. There were 100 witches, 

 all marketable, and among the other flat-fishes, 3 turbot, 13 brill, 1 

 halibut, 26 common dabs, and 7 flounders. Round-fishes, especially 

 haddocks, were scarce ; they included 2 cod, 7 codlings, 39 haddocks, all 

 but 1 being small, 18 whitings, and 2 catfish. The unmarketable fishes 

 consisted mostly of common dabs, whiting, and codling. The second 

 haul, in the same locality and about the same depths, was for four hours 

 and five minutes. The number of fishes secured was 792, of which 

 712 were marketable and 80 unmarketable. Plaice were better repre- 

 sented, the total being 492, all of them marketable, and consisting chiefly 

 of medium and small specimens. This catch also included a halibut, 3 

 turbot, and 14 brill, as well as 49 witches, all marketable, and 100 

 common dabs. There were also 7 cod and 11 codlings; haddocks were 

 equally scarce, only 26 being taken. A third haul in the same place 

 gave somewhat the same results. It was for four hours, and the aggre- 

 gate catch amounted to 863 fishes, 768 being marketable and 95 

 unmarketable. Plaice formed the bulk of the catch ; they numbered 

 375, mostly small and medium, and there were also 178 witches, all 

 marketable, as well as 37 brill, 79 common dabs, and 5 flounders. The 

 marketable round-fishes included 4 cod, 28 codling, and 43 haddocks, all 

 of the latter, except one, being small. 



In the three hauls in this place within the range of depth mentioned, 

 occupying altogether twelve hours and five minutes, 2251 fishes were 

 caught, of which 1991 were marketable and 260 unmarketable. The 



