the great shoals that inhabit the sea, what do we know? What do we know of the spawning, the growth, the food, the enemies of such fish; of the effect upon them of the saltness or temperature of the water, of the varying conditions of the air? Nay, more, – owing to the absence of any regular fishing statistics, we cannot tell the number of fish caught annually, the number of boats, the extent of the gear employed, or the time spent in the fishing. Without knowledge of this kind, upon what sort of evidence must we fall back? Upon that of the fishermen themselves. Now there is probably no finer class of men in these islands than the fishermen. Numbers of them have the bravery and simplicity of men whose life is one of struggle and hardship, and who are accustomed to look danger in the face. But it cannot be said that they are altogether fitted to give accurate evidence on a question of this kind. They have fished in the ways they fish now for centuries. Although constantly at sea, they have little leisure; and even if they had, do not possess the educated faculty necessary for close observation.
If they do observe, it is through the glasses of tradition, handed down to them by their forefathers, and anything beyond the rim of these they will not see. Further, in evidence so obtained, there is always great difficulty in separating facts from inferences, especially when the matter to be investigated is closely bound up with the interests of the witness. In addition to all this, the fishermen have no means but memory of comparing the results of present with those of former years. No records of their takes are kept, except such approximations as may be reached through the fish-curer and the fish-merchant, – no accounts of the amount of fish they sell, or the money they make in each year – of the time spent at sea, or the state of the weather in each season. Finally, in the words of the Commissioners –
"The increase in the number and size of the fishing-boats, and in the efficiency of their apparatus, make it difficult to say how far the supply of fish brought to market is an accurate test of the increased or diminished productiveness of the fishing-grounds. Nor do the grounds themselves always remain the same. New grounds are discovered in addition to those formerly used, and in some cases old grounds are abandoned."
In view of these many difficulties that met them upon the threshold of their investigation, the Commissioners seem to have adopted the best course that was open to them. While they were occupied themselves in taking evidence from the fishermen and trawlers, Professor M'Intosh, of St Andrews University, was directed to carry on a series of experiments as to the actual effects of the trawl. For this purpose a sum of £200 was advanced by the Treasury, and arrangements were made with owners of steam-trawlers at Granton and Aberdeen, under which the Professor was to be taken on board for the ordinary trips, and allowed to register the contents of the trawl-net. The chief object of these experiments was to obtain accurate information respecting the destruction of immature fish and spawn, said to be caused by trawling. Professor M'Intosh began his voyages in January 1884, and continued them till the end of August in the same year. During their continuance, ninety-three hauls of the trawl were made, upon the ordinary fishing-grounds off the Scotch coast, the results of
