COUNCIL — SEPTEMBER 1922 — 42 — 



3) Investigations as to the occurrence of larval and postlarval stages of the cod, as 

 well as the occurrence of young-cod. 



4) Investigations as to the rate of growth of the cod, as well as its age, length and 

 weight at first maturity. 



6) Investigations as to the food of the cod in the various stages of its development. 



6) Investigations of the migrations of the cod, by means of marking- experiments. 



7) Similar investigations are to be made regarding the flounder, especially in the 

 northern part of the Baltic. 



8) Investigations as to the Baltic herring, in certain selected places; Gotland and 

 Stockholms Skärgard are proposed for Sweden; and for Finland; the eastern part 

 of the Gulf of Finland. These investigations have the aim to state the racial char- 

 acters, the spawning seasons, the spawning areas, the rate of growth and the year- 

 classes, as well as the food of the Baltic herring. Special stress is laid upon the in- 

 vestigation of the Baltic Herring, and its relation to the deficit of oxygen in the deep- 

 water. 



9) Similar investigations are to be made on the foodfishes of the southern Baltic. 



III. Simultaneously with the investigations mentioned in II, investigations are 

 to be made on the plankton and on the hydrographical conditions. 



IV. The cruises in the northern part of the Baltic will be continued, and hydro- 

 graphical observations in the southern part of the Baltic will also be made. 



V. Observations from lightships and from adequate points of the coast will 

 be made in the Baltic on temperature, salinity and currents in the surface 

 and at different depths with a degree of frequency sufficiently high to follow 

 the hydrographical variations in the Baltic. 

 VI. The possibility of making serial observations of oxygen (temperature and 

 salinity) down to greater depths at selected points (e. g. off Christiansö, 

 Visby, and Market), is to be discussed between the hydrographers of the 

 countries interested. 

 VII. Continuous observations of sea-temperatures by means of thermographs to 



be made the subject of preparatory experiments. 

 VIII. Monthly mean values of the hydrographical observations taken from light- 

 ships in the Baltic shall be published in the Bulletin Hydrographique. 



