NOTES ON THE SHAD AND ALEWIFE. 457 



B— NOTES OX THE SHAD, AS OBSERVED IN THE DELA- 

 WARE RIVER. 



By J. H. Slack, M. D. 



1. — THE IMPORTANCE OF THE SHAD AS A FOOD-FISH. 



Among the fishes of the eastern coast of North America the shad 

 stands pre-eminent. From South Carolina to the Bay of Fnndy they 

 are found in every river, and the number annually captured must amount 

 to many millions ; the catch in the Delaware River alone, during the 

 season of 1872, being at least two and a half millions. 



2. — THE DECREASE IN THE DELAWARE. 



The catch in the same river, however, varies greatly from year to 

 year, and the reason ior this is most probably as follows: Repeated ex- 

 periments have shown that three years are required to mature the female 

 fish, though the young males, called offal-fishes and rebel-shad, return 

 during the second season. A heavy freshet during the periotl of spawn- 

 ing may bring down upon the spawn torrents of liquid mud, smothering 

 the ova and destroying the life of the embryo fishes. The results of this 

 will not be apparent until the third season. Unfortunately full and ac- 

 curate statistics for a series of years are wanting, save in the case of one 

 fishery, that of Dr. B. P. Howell, of Woodbury, New Jersey. This fish- 

 ery has been in the possession of one family since prior to the year 1700, 

 and a careful record of each haul of the seine has been kept. From 

 this record it would appear that until the introduction of the gill-nets, 

 1820-'25, the catch averaged about 130,000 per annum. 



Not to enter into detailed statements, but dividing the period between 

 1818 and 1873 into four cycles, each of which may be taken as represen- 

 tative of the intervening period, we have : 



Average catch, 1818 to 1822, 131,000 per annum. 



Average catch, 1815 to 1849, 66,890 per annum. 



Average catch, 1865 to 1869, 60,739 per annum. 



Average catch, 1870 to 1873, less than 25,000 per annum. 



The season of 1873 did not pay expenses. But not only have these 

 fishes decreased in numbers, but also in size. In 1843 shad of seven 

 and eight pounds weight were by no means uncommon, and the average 

 run was between five and five and a half pounds. Now in the Delaware 

 River a four-pound fish is a curiosity. A catch is recorded as having 

 been made near Burlington, New Jersey, in 1843, of three hundred and 

 seventeen shad, averaging ov^er six pounds each. Forty shad then filled 

 a i^ork-barrel, mackerel- barrels not being in use. Over a hundred of 

 the present deteriorated fishes are now required for this purpose. 



3. — THE CAUSES OF DECREASE. 



The cause of this is evident. The size of net-mesh in the liver 

 has been greatly reduced ; only the smaller fishes can pass up the river 



