66 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



numbers of fish, however, called out the fishermen, and there was a 

 steady decline auuually in the yield, and had it not been for artificial 

 propagation there would not be shad enough remaining in the river 

 at present to warrant any fisherman in using a hundred-fathom seine. 

 Fish culture, however, was brought in as a restorative. Each year since 

 1873 the United States Fish Commission has hatched and deposited 

 from one million to ten million, the numbers increasing annually. The 

 principal result, however, has been to prevent annihilation rather than 

 to cause considerable increase in the fisheries. The number of shad re- 

 ceived at the Washington market annually for the past five years was 

 as follows : 



1879 311, 585 



1880 320, 799 



1881 521, 3(38 



1882 350, 292 



1883 261, 474 



In spite of the best efibrts possible during these years the catch has 

 declined. That for 1883 is smaller than might reasonably have been 

 expected, because the temperatnre of the river happened to be unusually 

 low during the spawning season, and there is good reason to believe 

 that many fish were diverted to other tributaries of the Chesapeake 

 which would legitimately have come into the Potomac as a fruit of fish- 

 culture on that river. 



The fish of our rivers have not only to contend with enemies within 

 the water, such as a great variety of carnivorous fishes, the destruction 

 of their eggs by numerous forms of aquatic animals, the injuries of ab- 

 normal temperature and sudden changes thereof, and the damage pro- 

 duced by sawdust, sewage, and other filth introduced into the rivers, 

 but the aggressive character of our citizens has told against the food- 

 fishes in increasing ratio annually. The increase of population produces 

 a corresponding increase in the demand for these fishes, but the numer- 

 ous facilities which modern inventions have brought to the aid of the 

 fishermen in the way of wholesale appliances for capturing this kind of 

 food, complicate the question exceedingly. If fishing with rude api)li- 

 ances a hundred years ago was suflflclent to exhaust a river of shad, what 

 may be said of the ingenious traps and the miles of netting operated by 

 horse-power with which fish are met to-day ? To successfully run the 

 gantlet of a series of nets, but a few rods or miles apart, upon a con- 

 siderable portion of the length of the river, and to elude the fishermen 

 even on a flood tide at midnight, has become practically imijossible. 

 Fish culture thus has all the natural disadvantages of a hundred years 

 ago to contend with, and has the accumulated ingenuity of nineteen 

 centuries to circumvent, in order even to maintain a decent supply of 

 food-fishes. 



A striking example of the task of fish culture may be found at the 



