406 SECOND INTERNATIONAL CONFERENCE, 



V. 



§ 10. With reference to the question of the extent of the destruction 

 of immature (undersized) fish in the ordinary practice of sea fishing, it 

 shall be a primary object of the fishing experiments to delimit those 

 parts of the sea in which young food-fishes, especially plaice and 

 haddock, occur in great abundance, and to subject these regions to exact 

 biological investigation. 



Attempts shall also be made in the larger fishing ports of the North 

 Sea to determine the relative number of such young food-fishes below 

 the average size of maturity (especially plaice and haddock), which are 

 landed by the different methods of fishing, and at different times of the 

 year. 



§ 11. It is desirable to determine the amount of the catches of immature 

 {undersized) food-fishes, especially of plaice and haddock. To this end the 

 official statistical records in the fishing ports should he utilised in the first 

 place, and in the second place the fishing experiments and the analysis of 

 their catches as specified under II. § 2, and V. § 10. Still richer material 

 will he ohtained, if favourable opp)ortunities also occur for sendiyig com- 

 petent experts on board fishing vessels, in order to determine exa.ctly the 

 cpiiantity and size of the immature {undersized) fishes on the fishing grounds 

 themselves, and to record the same for each catch according to a uniform 

 scheme to he determined. 



Plankton and Bottom Fauna. 



VI. 



§ 12. Qualitative plankton samples are to be taken as often as possible 

 during the hydrographic seasonal cruises, and not merely from the sur- 

 face, but also by vertical hauls. 



I 13. It is desirable that qualitative plankton samples should also he 

 regidarly taken in large quantity on other cruises and at definite coast 

 stations, in order to provide plentiful material for more detailed stiidy of 

 the plankton from systematic biological and chemical points of viciv. The 

 use of closing nets and loater -bottles, as 2vell as the filtration of the smallest 

 organisms, is recommended. 



VII. 



§ 14. If circumstances permit, quantitative hauls shall be taken with 

 Hensen's plankton-net at the chief hydrographic stations, and be placed 

 through the agency of the Central Bureau at the disposal of those in- 

 vestigators who are prepared to undertake a thorough quantitative 

 investigation. 



