496 BULLETIN OF THE BUREAU OF FISHERIES, 
of the number of small sponges taken. The harpoon and naked diving are 
regarded as harmless, and it is generally held that the beds could not be seriously 
injured by those methods alone. 
On the western side of the Atlantic the case is different. In Cuba and the 
Bahamas, and until recently in the United States, the diving machine has not 
been used and the dredge is unknown. Hooks, the equivalent of the Mediter- 
ranean harpoon, were the only implements employed, yet the complaints of 
waning productiveness of the sponge grounds are quite as loud and, in some 
cases at least, as well grounded. 
The earlier statistics of the Florida fishery are nearly valueless for the 
determination of the productiveness of the beds. The sponges are bought by 
bunches which vary in weight with the size and character of the sponges and 
the manner in which they are strung, and the only comparative weights or 
quantities which are available are those of the packed goods. Unfortunately 
these weights are not those of the pure sponges but of sponges plus salt, sand, 
glucose, and other materials used in loading. Were this loading uniform the 
statistics would still be of some value for the purpose of the present inquiry, 
but the amount of foreign matter introduced has gradually increased since the 
practice was recommenced, about 1895, after an interval of comparatively honest 
packing, until in 1903-4 I found it to range between roo and 150 per cent of 
the true weight of the sponges. At that time, and until the heavy influx of 
sponges from diving operations, practically all sheepswool sponges and some 
of the cheaper grades were heavily loaded, and even much of the small quantity 
sold as “pure”? was more or less ‘“‘doped” with salt, glucose, glycerin, and a 
little litharge. Since 1903 the statistical weight of the catch has been based 
upon an assumed approximate average weight of the bunches and the result is 
probably more accurate. 
Considering the total yield of both Bay and Key grounds, the average 
catch of sheepswool sponges between 1895 and 1899, inclusive, was 173,043 
pounds, while between 1900 and 1904, inclusive, it was 186,155 pounds. In the 
latter period, however, there were two years, 1901 and 1903, when clear water 
on certain grounds rarely fished gave the spongers access to practically virgin 
bottom. It should be stated, however, that in the latter part of this term 
the number of men and vessels employed exhibited some decrease. 
In the period from 1905 to 1908, inclusive, there occurred a great increase 
in the production, the average product of sheepswool sponges being 313,697 
pounds. This was due to the introduction of diving. 
Considering the production in its relation to effort expended in the fishery, 
we find that each man engaged in hooking from 1900 to 1904, inclusive, pro- 
duced an average of 100 pounds of sheepswool sponges per year as compared 
with an average of 81 pounds for the years 1905 to 1908, inclusive. The 
