38 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



It sboLikl be noted, however, that wherever representatives of this 

 genus of fishes occur there is doubtless an opportunity for establishing 

 new industries of great value. It would be well worth while for enter- 

 prising fishermen to investigate this subject. The Government of Japan 

 has recently employed one of the best informed of our New England 

 fishermen * to instruct the natives of that country in the arts of catch- 

 ing and preserving food-fishes. 



As has already been stated, there are abundant supplies of these fish 

 on both sides of the South Atlantic. There is apparently no reason why 

 extensive manufacturing interests may not be inaugurated in Brazil, the 

 Argentine Eex)ublic, Paraguay, and Africa. 



12. — THE ARRIVAL AND DEPARTURE OF THE SCHOOLS. 



Causes influencing times of arrival and departure. 



02. The date of the earliest appearance of the schools of menhaden at 

 any given point upon the coast corresponds very closely with that of the 

 arrival of scup, shad, bluefish, and other of the non-resident summer 

 species. It depends primarily upon the temperature of the water. This 

 element is of more imiwrtauce, perhaps, in the case of the menhaden 

 than with the carnivorous fishes, since the food-supply of the former 

 is not likely to be affected by changes of temperature. There are other 

 questions to be considered, such as the movements of hostile species and 

 the direction of the prevailing winds, though the latter may, perhaps, be 

 merged in the question of temperature. Their departure is regulated by 

 the same causes, though, since their food-supply is less uncertain, they 

 linger later in our waters than most of their companion species of the 

 spring. 



Material available for the determination of dates. 



C3. The material for determining the movements of the schools is very 

 unsatisfactory, though perhaps of necessity so. Although many of 

 our correspondents give dates of arrival and departure, these are under- 

 stood to be merely approximations to the truth. The only series of 

 observations showing the dates of the arrival of menhaden for a period 

 of several successive years is one from the Waquoit weir, and this profes- 

 ses to show nothing except the date at which the fish began to be 

 abundant. In the nature of the case, observations of a more definite 

 nature are impracticable. Since so little that is definite can be recorded, 

 it may be desirable to review the statement, of some of our correspond- 

 ents, thus putting on record a series of observations all carefully made 

 and many of them extending over a long period of years. In this way 

 the movements of the menhaden at different points upon the coast 

 will be described more accurately and graphically than they could be by 

 any compiled account, however carefully it might be prepared. It is 



* Capt. U. S. Treat, of Eastport, Me. 



