— 400 



C/5 

 Q 



Z 



o 



a. 



CO 



o 



UJ 



300 



200 



CO 



z 



Q 



Z 

 < 



100 



o 



1946 



1950 



1954 



Figure 18.— Total landings of wcxjI, grass, and yellow sponges, 1917-58. 



obtained by one diving boat is equivalent to the 

 return obtained by 4.5 hooking boats. On this 

 basis (table 12) only 11.2 percent of the number 

 of boats operating in 1946 were still working in 

 1951. 



By 1948 the value per pound of wool sponges 

 had dropped from a 1946 high of $30 to an aver- 

 age of just over $6. The total return for the 

 year 1948 was $466,000 or more than $2 million 

 less than was received for wool sponges alone 

 in 1946. Although the return per unit of effort 

 remained at about the same level and even in- 

 creased as more boats left the fleet, it was not 

 possible to operate economically with the 

 lowered price per pound. As a result, continued 

 withdrawal of boats took place with a 



corresponding decrease in sponge landings so 

 that by 1951 the total take of sponges was less 

 than 3 percent of the peak production year of 

 1936, with a dollar return of less than 3 per- 

 cent of the peak value year of 1946. 



If the sponging fleet had been as large in 

 1951 as in 1946, the yield per unit effort would 

 have declined because of the limited sponging 

 area. In this second postdisease period, a re- 

 duction in the sponging fleet was accompanied 

 by a sizeable increase in the take per unit of 

 effort (as in 1948) — something that had never 

 happened in the history of the industry. 



By 1957 there were 7 diving boats and about 

 35 hooking boats actively sponging. These boats 

 landed sponges as an annual rate of about 29,000 



53 



