364 



THE POPULAR SCIENCE MONTHLY. 



man without their aid, and as their natural instincts impel them 

 to bring to our very doors this great addition to our food-supply, 

 their economic value is very great, as they put at our service a 

 vast area of the surface of the globe which would otherwise be 

 entirely beyond our control. The extinction of the shad would, 

 therefore, be a national calamity. 



In 1880 the fishermen believed, apparently with good reason, 

 that the rapid decline was due to improper methods of fishing — 

 to the erection of pounds and weirs along the shores of the salt 

 bays and sounds, where the fishes were captured in great numbers 

 long before they had reached their spawning-grounds. It was 

 urged that, if these obstructions were removed, and all the shad 

 were permitted to reach fresh water before they were captured, 

 enough eggs would be deposited each year to keep up the supply, 

 but that the destruction of such great numbers in salt water must 

 necessarily result in extermination. This seemed to be good logic, 

 but in the spring of the year 1888 more shad were caught in salt 

 water than were caught altogether in the year 1880 in both fresh 

 and salt water ; and yet the shad-fisheries are now increasing in 

 value from year to year, while in 1880 they were in danger of 

 destruction. 



To what is this change due ? In 1880 the United States Fish 

 Commission began systematically and upon a large scale the work 

 of collecting the eggs from the bodies of the shad which were 

 captured for the market in the nets of the fishermen. These eggs 

 were artificially fertilized and hatched; the young fishes were 

 kept for a few days in captivity in glass jars ; they were then set 

 at liberty in the fresh-water streams, and the waste of eggs was 

 thus prevented. This work has been prosecuted steadily for eight 

 years, and the results are briefly summarized in the following 

 table : 



YEAES. 



Shad captured in 



salt or brackish 



water. 



Shad cap tn red in 

 fresh water. 



Total. 



Percentage of 



increase over 



1880. 



1880 



1885 



1886 



1887 



1S88 



2,549,544 

 3,267,497 

 3,048,768 

 3,813,744 

 5,010,101 



1,591,424 

 1,906,434 

 2,485,000 

 2.901,661 

 2,650,373 



4,140,968 

 5,172,931 

 5,5S4,368 

 6,715,405 

 7,660,474 



25 

 34 

 62 

 85 



The money value of the excess in 1888 over the total catch in 

 1880 is more than $700,000. The conditions are now more unfavor- 

 able than ever to natural reproduction, and there can be no doubt 

 that, if no shad had been produced by man since 1880, and if all 

 the other conditions had been as they are, the fisheries would now 

 be valueless. The mature shad which run the gantlet of all the 

 pounds and traps in the lower waters, and finally reach the mouths 



