734 MARINE PRODUCTS OF COMMERCE 



At first the fishery was confined to the waters adjacent to the Florida Keys, 

 but from about 1868 to 1879 extensive beds of superior sheepswool sponges 

 were found in the Gulf of Mexico, north of Cedar Key, and a little later south 

 of that point, extending as far as Anclote Key. Key West maintained its suprem- 

 acy in the sponge market until about 1899, when Tarpon Springs, more advan- 

 tageously located in respect to the valuable Gulf of Mexico grounds, supplanted 

 it. The introduction of diving in 1905 and the establishment of Tarpon Springs 

 as the headquarters for the Greek divers, confirmed the position of that place 

 as the principal market. At present over 85 per cent of the total product of Florida 

 sponges is marketed through the sponge exchange, a nonprofit organization estab- 

 lished in 1908. 



Decline in Production 



The production of sponges in the United States steadily increased from 1920 

 to about 1936—1937, when it reached its maximum of over 600,000 pounds, val- 

 ued at more than 1.2 million dollars. In 1937 the industry employed 72 diving 

 outfits, 256 sponge hooks, and gave livelihood to 949 fishermen. The decline in 

 the quantity of sponges on fishing grounds brought down the production figure 

 to only 158,000 pounds in 1947. The scarcity of sponges greatly increased their 

 price, and in 1946-1947 the value of the industry was 2.9 and 1.7 million dollars, 

 respectively, greatly exceeding the 1936-1937 figures in spite of the decreased 

 production. 



The decline of the sponge fishery has not been limited to Florida waters, but 

 affected the entire Western Atlantic production, which dropped from 1,750,000 

 in 1938 to only 300,000 pounds in 1947. 



The principal cause of the decline has been the blight or wasting disease which 

 appeared in the fall of 1937 on the sponge grounds of the Bahamas and rapidly 

 spread over the entire West Indies. The disease extended as far south as British 

 Honduras, where it destroyed a large stock of cultivated sponges grown at Turneffe 

 Lagoon, while in the north it depleted the natural grounds, from Key West to 

 Carabelle, Florida. 



Investigation, conducted jointly by the American and British biologists, deter- 

 mined that the cause of the disease was a fungus infection which was spread by 

 a System of water cvirrents. The blight was particularly severe among the culti- 

 vated and densely planted sponges at Andros Island (Bahamas) and in British 

 Honduras. 



Since the recovery of sponge populations on the affected grounds has been 

 very slow, the former productivity of the grounds may not be restored in less 

 than 20 or 30 years. The situation is aggravated by the complete lack of scien- 

 tific management of sponge resources. Sponge grounds off the Florida Coast have 

 never been surveyed, and consequently no accurate information exists of their 

 extent and present population density. Likewise, the biology of American com- 

 mercial sponges has been so little studied that data of their reproduction, rate 

 of growth, normal mortality, as well as the knowledge of the ecological conditions 

 affecting sponges, are lacking. In the absence of these essential data no practical 

 conservation measure could be suggested. 



At present the enforcement of a 5-inch minimum size law is the principal con- 



