REPORT OF COMMISSIONER OF FISH AND FISHERIES. IX 



tions of organic life in the sea, aud their variatious, the final object, 

 of course, was a practical one, namely, the determination of the 

 facts embraced under the third head. As, however, very little was 

 known in reference to the natural laws of distribution, &C., of the 

 useful animals, it became necessary to investigate them from a sci- 

 entific point of view; so that the primary inquiries were strictly 

 scientific, the deductions therefrom leading to the practical end. 



The initiation of the Franco-German war interfered very materially 

 with this programme, and it was not until 1871, and nearly at the same 

 time with the American investigations, that operations were actually 

 commeuced. The commission consisted of Dr. H. A. Meyer, Dr. K. 

 Mobius, Dr. G. Karsten, aud Dr. V. Hansen, each gentleman having 

 charge of some special branch, aud all co-operating toward the common 

 result. Fixed stations were established at various points for the pur- 

 pose of observing the variations of atmospheric conditions, the daily 

 changes of temperature of the water, and the occurrence of special phe 

 nomena of animal aud vegetable life ; and for several months iu the 

 year the commission, with its assistants, was engaged in researches at 

 sea, prosecuted upon the government steamer Pommerania, placed at 

 its disposal, under Captain Hoffmann. Upon this work the commission 

 has been engaged foe three successive seasons, and has just published a 

 report of its operations during the year 1871. 



and a little earlier in the north than iu the south. At Yarmouth the herring-season is 

 iu October aud November ; off the Kentish coast, in November and December ; along the 

 south coast of England, from October to December ; off Cornwall, in August aud Sep- 

 tember ; iu the North Channel, in June and July ; and in the Hebrides, May and June. 



It is suggested by the Scottish committee iu their report that when the periods of mi- 

 gration on all parts of the British sea -coast will have been calculated as closely as iu 

 Scotland, these vrill be found to bear a critical relation to the annual epochs of the 

 temperature (^f the sea. This gives a renewed importance to the inquiries undertaken 

 by the United States Signal-Service aud the Fish Commission, on the American coast, 

 iu the way of determining of the sea-temperature, &c., as connected with a very 

 important branch of our domestic industries. 



In this connection we may state that the spawning-season of the herring, and the 

 time of its catch, vary remarkably in different portions of our own coast. Thus, 

 in parts of the Bay of Fundy and in the Gulf of Saint Lawrence, it takes place in 

 May and June, as in the Hebrides ; at the Southern ,Head of Grand Manan, the great 

 spawning-ground, it occurs iu September, commencing possibly in August, and ex- 

 tendiug into October; taking place later and later in the season as we proceed south- 

 At the most southern point at which the herring is positively known to spawn, 

 namely, off' Noman's Laud and possibly Block Island, this does not occur until Decem- 

 ber aud January. 



From this we may draw the inference that a certain minimum of temperature, 

 rather than a maximum, is needed for the operation in question ; and this occurring 

 iu the autumn, that the proper temperature is reached later and later as we proceed 

 southward. 



It is to be honied that the temperature-observations now being made by the United 

 States Fish Commission and by the Signal-Service may enable us to solve these 

 problems and to co-operate with our Scottish scieutitic brethren in getting at the true 

 relation between physical conditions aud the movements of such important food- 

 fishes as the herring, mackerel, cod. &c. 



