AQUATIC PKUDUCTS AS FEKTILIZEKS. 273 



FERTILIZERS FROM CRUSTACEANS. 



Ainoiii;- tlie most curious of tho mariue products used for fertilizer 

 is tlie liorseslioe crab {LiDiulnti pohjphemus), wliicli is found in com- 

 parative abundance at several points on the Atlantic coast and espe- 

 cially on the shores of Delaware Bay. The use of this fertilizer dates 

 back at least a hundred years, old records indicating its employment 

 by the farmers of Cape Cod in the eighteenth century. It is reported 

 that they were first used in the Delaware Bay region about fif tj^ years 

 ago. In that section they are taken during May and June, when large 

 numbers visit the shallow waters for spawning purposes. During the 

 remainder of the year they are scarce inshore, although a few may be 

 obtained. They are secured by picking them up at night on the shore 

 either by hand or with pitchforks, or thej^ are taken in pound nets 

 constructed especially for that purpose. The pound nets cost $25 to 

 1^75 each, and they secure by far the greater number. At present the 

 catch is verj^ much less than it was twenty years ago. In 1880, accord- 

 ing to the returns of the United States Fish Commission, the total 

 catch in Delaware Bay amounted to 4,300,000 in number, worth 

 116,300. In 1890, it was only 1,939,670, worth $8,580, and in 1897 it 

 was still further reduced to 1,206,095, worth $8,393. The value of 

 the horseshoe crabs ranges from $4 to $8 per thousand and the weight 

 averages about 2 pounds each. 



In pireparing them for fertilizer, the entire crabs are sometimes 

 merely stacked in piles until they putrefy and become somewhat dry, 

 when they are broken into fragments and composted with muck, 

 lime, or other suitable materials. Two or three small factories exist 

 at which the crabs are dried and ground, or they are ground while 

 green and then mixed with sodium sulphate or sulphuric acid. The 

 product sells for $15 to $25 per ton, and is an excellent fertilizer for 

 grain and fruits. The output in 1880 approximated 1,950 tons, in 1890 

 it was reduced to 880 tons, and in 1901 it was still further reduced to 

 500 tons. 



When lobsters were canned on the coast of Maine, a desirable grade 

 of fertilizer was made from the shells and other refuse of the can- 

 neries. This refuse was sold at a nominal price at the factories, or 

 given away for the hauling. The farmers collecting it would usually 

 dry and grind it and then spread it on the land. Letters patent were 

 issued to William D. Hall, in 1865, for the preparation of this ferti- 

 lizer, but his rights in the matter were never protected. This waste 

 is thus utilized at the present time at the lobster canneries in Nova 

 Scotia and New Brunswick. 



The shells of shrimp produced in the fisheries of California and 

 Louisiana are used to a considerable extent for fertilizer, which is 

 emploj^ed by tlie Chinese not only on the Pacific seaboard but also in 

 the Orient. The shells are removed from the dried shrimp and sold 



F. C. 1903 18 



