SOME KESULTS OF THE INTERNATIONAL FISHERY INVESTIGATIONS. -ioO 



be made to elaborate legislation of this nature. Into the latter 

 questions we cannot enter here, although it is evident that they are 

 at least of equal importance to the scientific issues involved. But 

 at any rate, no one would recommend general discussion of the question 

 apart from far-reaching and patient investigation of the natural history 

 of the plaice in the sea at every stage of its life. In the investigation 

 of the latter question, so far as it has been carried out, three main lines 

 have been followed by those engaged in the International Fishery 

 Investigations: (1) the distribution of the plaice on the various fishing 

 grounds, with respect to the size and age of the fish present from month 

 to month throughout the year ; (2) the migrations of the fishes ; and 

 (3) the food of the plaice. Other lines of investigation have been 

 followed, but in the main attention has been focussed on those indicated 

 above. The distribution has been studied by means of fishing experi- 

 ments, that is, numerous hauls with trawl and other nets made by the 

 exploring steamers on tlie fishing grounds frequented by the commercial 

 vessels, and statistically by means of a study of the results of the 

 fishery by the fishing fleets themselves and by the examination of 

 samples of fish caught by the trawlers and examined in detail after- 

 wards. The fishery experiments have been made by the various 

 scientific vessels and naturalists of the national staffs, while the 

 statistical work has been mainly carried out by the Bureau of the 

 International Council and by the English Board of Agriculture and 

 Fisheries. 



Now the method of fishing experiments is, of course, of limited 

 application, and conclusions derived from such results must be 

 cautiously made. Like all scientific methods which depend on the 

 examination of "samples," it is open to the objection that the sample 

 may not really represent the general conditions. Such objections, for 

 instance, would apply to thermometric or barometric charts representing 

 the meteorological conditions of an extensive land and sea area at 

 a given time. That is, the readings of the instruments, while true for 

 the immediate area, might differ notably from those which would be 

 obtained in an adjacent area where no readings had been made. The 

 results obtained by fishing with a trawl net on twelve days in the year 

 could not be compared, with any degree of certainty, with the results 

 obtained by fishing with the same trawl on the twelve corres})oiuling 

 days of the following year in the same place. That is to say, so many 

 accidental circumstances might iuQuence the nature and amount of the 

 catches made Ity the net that it would l)e risky to conclude that fisli 

 were more or less numerous at the given place in one year than in 

 the other. But though sucli limitations must be imposed on the useful- 

 ness of fishery experiments, it is nevertheless the case that these are 



