70 U. S. BUREAU OF FISHEBIES, 



account of those of a martial character allowed the fisheries to recuperate, so that in 

 the years immediately succeeding the war it was found that they had in a measure 

 recovered from their former depletion. In 1878, the minimum of production was 

 attained, during which season less tlian 200,000 shad were taken in the entire river. 

 In 1879 the results of previous artificial propagation first manifested themselves, and 

 there was a considerable increase in the run of shad, from which time the shad fisheries 

 steadily increased, until in the season of 1880 nearly 600,000 were taken. 



In the years preceding 1896 Stevenson (ibid., 1898) states that the 

 average annual yield was about 750,000. From 1896 to 1921 statis- 

 tics of the number of shad caught are available as follows: 1896, 

 684,063 shad; 1904, 372,647; 1909, 203,971; 1915, 182,402; 1919, 

 544,469; 1920, 529,358; and 1921, 405,872. Following 1878 it is 

 apparent that the fisher^^ was at a very low ebb in 1885, 1905 to 1907, 

 1909, 1914, and 1915, with occasional years of relative abundance. 



Factors which have contributed to the depletion of the supply are : 

 Intensiveness of fishing operations; changed conditions in the river, 

 resulting from the advance of civilization, productive of conditions 

 in its waters destructive to maintenance of supply of our important 

 anadromous species; and such fluctuations as may be induced by 

 weather conditions affecting the migration of the shad into and up the 

 river. Of the first much has been said and written, of the second rela- 

 tively little. Some close students of the question suggest that the shad 

 is doomed, that the changed conditions in our rivers resulting from the 

 advance of civilization are steadily growing more unfavorable for 

 reproduction and that it is only a question of time until this important 

 fish disappears from our waters. Certain it is that there is need for 

 fui-ther investigations to determine the relative importance of the 

 different factors contributing to the decline of this fishery and the 

 extent to which fish-cultural operations and protective legislation 

 are helping to maintain the supply. Such investigations should 

 include studies of the changes taking place in the rivers and the 

 possibilities of restoring them to a condition favorable to the repro- 

 duction and growth of such anadromous fishes. The annual statis- 

 tical canvasses are being made for the purpose of yielding helpful 

 information to those who may undertake such an investigation. 



NOTES ON SPONGE FISHERY. 



In 1921 the quantity of sponges sold at the Sponge Exchange, 

 Tarpon Springs, Fla., was 386,390 pounds, valued at $540,093, of 

 which 173,723 pounds, valued at $463,170, were large wool; 63,786 

 pounds, valued at $28,705, small wool; 70,218 pounds, valued at 

 $30,428, yellow; 65,745 pounds, valued at $12,623, grass; and 12,918 

 pounds, valued at $5,167, wire. The prices of the small wool sponges 

 were so low in the latter part of 1920 that several thousand bunches 

 were held over for sale in 1921. For this reason the 1921 totals of 

 this kind were larger than for the preceding year. It is estimated 

 that sponges to the value of $40,000 were sold outside of the exchange 

 at Tarpon Springs. 



