Table 14. --Harvest of Florida sponges, 1950-62 



for all sponges both as to numbers and average 

 price. 



In July 1956, on my recommendation, the 

 Branch of Statistics of the Bureau of Commer- 

 cial Fisheries changed the method of gathering 

 data on the price and quantity of the sponges 

 landed. These changes will improve the relia- 

 bility of the statistics on sponge landings and 

 values and will aid any biological and market 

 analyses in the future. 



There has been a steady increase in the land- 

 ings of sponges from 1951 onward (table 14). 

 This increase is caused largely by the in- 

 creased sponge fleet, except in 1955, when the 

 number of sponges taken almost doubled the 

 take of the previous year. It would appear that 

 a large number of sponges reached egg- produc- 

 ing size in 1955, and assuming that conditions 

 for spawning were favorable in 1955, there 

 should have been a large number of sponges 

 of legal size from this spawning reaching egg- 

 bearing size in 1957 and throughout 1958. 

 Records of landings for 1957 and 1958 indicate 

 that this probably had come about. During the 

 first half of 1957 the total landings were almost 

 equal to the total take of 1956. Unfortunately, 

 during the late spring and summer there was 

 a heavy mortality of wool sponges due probably 

 to freshening of the water. Samples examined 

 indicated that this was the reason. Conse- 

 quently, landings fell off during the next two 

 sponging periods, but reports from the fall 

 trips of 1958 show that there has been a rapid 

 return of the sponges, to the level of 1956 at 

 least. 



As long as the sponge fishery is entirely 

 dependent upon sponges growing in the shallow 

 area, the fishery will be plagued by intermit- 

 tent adverse conditions. The industry cannot 

 be stabilized until the sponges are growing in 

 quantity in the deeper water. 



Probable Reasons for Annual 

 Fluctijations in Landings 



Any probable increase in the number of 

 sponges growing in shallow water will be predi- 

 cated on the following: 



1. Concentrations of mature sponges in all 

 parts of the areas are greater than the 

 minimum required for adequate fertili- 

 zation. 



2. Fishing for sponges will not deplete the 

 present beds or seriously reduce the con- 

 centrations below the level required for 

 adequate fertilization. 



3. No serious disease or adverse ecological 

 condition such as a freshening of the water 

 will take place. 



Records of take per unit effort in various 

 areas, the wide daily fluctuation of take, and 

 the several local severe losses of sponges 

 because of adverse conditions point up the fact 

 that the concentration of the wool sponges is 

 erratic on the northern sponging grounds. It is 

 unlikely that the increase in concentration by 

 natural reproduction throughout the present 

 fishing grounds will increase by as much as 60 



56 



