EEPORT OF COMMISSIONER OF FISH AND FISHERIES. ix 



tions of organic life iu the sea, aud their variations, the final object, 

 of course, was a practical one, namely, the deterininatiou 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 5 so that the primary inquiries were strictly 

 scientific, the deductions therefrom leading to the practical end. 



The initiation of the Franco-G-erman 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 

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

 Mobius, Dr. G. Karsteu, and Dr. V. Hansen, each gentleman having 

 charge of some special branch, and 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 and vegetable life; and for several months in 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 for three successive seasons, aud has just published a 

 report of its operations during the year 1871. 



and a little earlier in the north than in the south. At Yarmouth the herriug-eeason is 

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

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

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



It is suggested by the Scottish committee in their report that when the jieriods of mi- 

 gration on all i)arts of the British sea -coast will have been calculated as closely as in 

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

 temperature of the sea. This gives a renewed importance to the inquiries undertaken 

 by the United States Signal-Service and 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 Fuudy and in the Gulf of Saint Lawrence, it takes place in 

 May and June, as iu the Hebrides ; at the Southern ^Head of Grand Mauan, the great 

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

 tending into October; taking place later aud later iu the season as we proceed south* 

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

 namely, oft' Nomau's Land and possibly Block Island, this does not occur until Decem- 

 ber and Januaiy. 



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 

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

 southward. 



It is to he hoped that the temperature-observations now being made by the United 

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

 Xiroblems and to co-operate with our Scottish scieutiilc brethren in getting at the true 

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

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



