VII 



we lind, by turning to the table of the yiekl on the Sus- 

 quehanna, that the ininimum catch for that river occur- 

 red the same year. The increase in the Susquehanna for 

 1880, however, was as marked as that in the Potomac ; 

 thereby clearly indicating such increase as being the 

 result of the de^Dosit of the artificially produced tish in 

 both these streams. 



The diagram will further show that ISTU^the first 

 year in which it is j^ossible to compare the yield of the 

 two localities — was comparatively a good year for the 

 Potomac fisheries and a Ijad one for those of the Susque- 

 hanna. The next year (1871) showed a decrease in the 

 Potomac, with a corresponding increase in the Susque- 

 hanna. The following year — 1872 — the catch in the 

 Susquehanna increased only 8,000 and that of the 

 Potomac 96,810. 



We next find the year 1878 to have been one of great 

 abundance in the Potomac, and of great scarcity in the 

 Susquehanna. In 1874 the Potomac decreased from 

 1,142,629 to 953,977; while the Susquehanna increased 

 from 516,000 to 583,000. 



We recognize in these statements the inevitable result 

 of successive years of over-fishing ; of disturbing the fish 

 on their spawning beds ; and of preventing them, alto- 

 gether, from reaching such beds. The diagram indicates 

 a continued, though somewhat irregular, downward 

 tendency in the yield of the Potomac from 1873 to 1878 ; 

 and of the Susquehanna from 1872 to 1877, the loss in 

 both rivers being finally arrested by the same means. 



It will be remembered that the work of shad hatching 

 was commenced in 1875, and was continued the following 

 year — j)rincipally at the head of the Bay. In 1876 and 



1877 large numbers of young iish were released ; aiid in 



1878 a slight increase of shad was observed in the waters 

 of the Bay — a remarkable feature of tliis increase being 

 the preponderance of small male iish. In 1876 our ope- 

 rations at the head of the Bay were not prosecuted on a. 



