18 Part IIT —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, &e. 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 were 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 Burghead 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, ouly 1 large plaice being talken. 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 cat fish. 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 aud 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 
