BULLETIN OF THE UNITED STATES I1SII COMMISSION. 2G7 



»4.-OR«AIVSC MATTER li\ THK BALTIC. 



By Prof. V. JIENSEN. 



[Abstract of a paper rend at the Sleswick-Holstein Physiological Association, Jan- 

 nary 12, 1885.]* 



An investigation to determine the quantity of organic mat tor in (lie 

 western portion of the Baltic, exclusive of the harbors and bays, has been 

 in progress since August, 1884, at the request of the commission for the 

 investigation of the German seas. 



The theoretical basis for such an investigation is given in a paper on 

 "The Occurrence and Quantity of Eggs of some Fish in the Baltic." t 

 The investigation was based on the supposition that the constant 

 shaking motion prevailing in the sea distributes all matter floating in 

 its waters almost evenly, and that, on the other hand, the conditions of 

 grorwth and increase for the various formations floating in the water 

 (partly objectless and partly with no other object than to seek food) 

 are everywhere the same in water of the same character. 



Practical investigations have tended to prove the correctness of this 

 theory. The distribution of matter was of course not absolutely even. 

 A shaking process would bring about a close approach to even distri- 

 bution, but could never make it perfect. Moreover, there was a lively 

 exchange in the basin in question between the waters of the Cattegat 

 and those of the Eastern Baltic, rendering the even distribution liable 

 to constant disturbances. It appears, however, that when the steamer 

 is anchored, aud successive columns of water (of 3, 5, 7, &c, meters 

 depth) are examined as to their contents, the entire quantity of organic 

 matter and of individuals is approximately proportionate to the volume 

 of water which has been examined; that therefore the distribution of 

 matter in this portion of the Baltic, whose depth rarely exceeds 20 me- 

 ters, corresponds approximately to this depth, in fishing a number of 

 times in succession in a column of water of equal depth, while the cur- 

 rent passes the anchored vessel, the catches will vary in quantity and 

 numerical composition, but the differences do not exceed 50 per cent. 



As far as could be ascertained, the catches in the Baltic between the 

 Holstein shores and the nearest Danish islands would not vary 50 per cent 

 from the average of the first catches referred to above. As there was 

 sufficient agreement between the results obtained by continuous fish- 

 ing- near the surface, as the steamer pursued its course, aud the results 

 obtained at points where a halt was made, a tolerably correct idea of 



* " Sitzung des plujsiologischen Vtreins, den 12. Januar 1865." From Mittheihingen fur 

 den Verein Schleswig-Holsteinischer Aerzle, Part X, No. 7, 1885. Translated from the Ger- 

 man by Herman Jacobsox. 



t See Fish Commission Report - , 1882, ]>. 427. 



