PROGRESS IN BIOLOGICAL INQUIRIES, 1939 73 
SPONGE-FISHERY INVESTIGATIONS 
Dr. PAvuL S. GALTSOFF, in charge 
Early in December, 1938, a heavy mortality broke out among the 
commercial species of sponge (wool, velvet, grass, reef, yellow, and 
hardhead) on the natural banks in the waters of the Bahama Islands. 
At the request of the Colonial Secretary of the Bahamas, and with 
the consent of the U. S. Department of State, Dr. Gaitsoff was de- 
tailed to Nassau, Bahamas, to collaborate with the British Depart- 
ment of Sponge Fisheries in conducting the necessary imvestigation 
of the cause of the mortality. This detail, which involved no ex- 
penditures on the part of the Government, continued from February 
15 to April 7,1939. During this brief period extensive hydrographical, 
chemical, and biological observations were made in the area of great- 
est mortality, near Andros Island, with additional observations on 
the Little Bahamas Bank and in the inshore waters around New 
Province Island. Laboratory and field experiments were conducted 
at the same time at Nassau and the field station at Mastic Cay, 
Andros Island. The records of a spread of mortality over the 
natural and cultivated sponge beds of the Islands indicate that the 
sequence of infection was from east to west. following the trend of 
water movements within this area. Determinations of s alinity, pH, 
dissolved oxygen, excess base, calcium, and analyses for phosphates, 
silicates, and heavy metals failed to disclose any factor which may 
have been responsible for the mortality. Microscopical examination 
revealed, however. the presence of fungal filaments in all diseased 
sponges. These filaments have not been found in healthy sponge 
tissues, nor in the remains of sponges which have been long dead. 
They are particularly abundant in the marginal zone between the 
newly dead and living tissues of diseased sponges. The infection 
spreads gradually through the tissues, starting often from an origin 
inside. 
In the experiments conducted at Nassau, and at Mastic Cay, it was 
possible to infect reef and wool sponges with the fungus by contact 
with fragments of infected sponges of the same species. The fungus 
was tentativ ely identified as Spongiophaga sp. By the end of F ebru- 
ary the diserse had spread to the northern coast of Cuba, and in 
March it was reported to have reached Key West, Fla. 
A survey of the conditions ef the Florida sponge fishery was made 
by Dr. Galtsoff immediately upon his return from the Bahamas. It 
was reported that during the first week of March large numbers of 
wool, yellow, and grass sponges were noticed on the reef extending 
along the Atlantic side of the Florida Keys. In a short time similar 
conditions were observed from Key West to Biscayne Bay. The 
mortality occurred almost simultaneously in Florida Bay, Barnes 
Sound, and Biscayne Bay, apparently spreading through the numer- 
ous passages which intersect the Keys and connect the waters of the 
Atlantic with those of the Gulf. Gradually the epidemic progressed 
westward over the entire area of Florida Bay as far as Cape Sable. 
Reports of the destruction of sponges in this region were received 
about the middle of April. At that time the mor rtality among com- 
mercial sponges reached such proportions that fishing became un- 
profitable, and had to be stopped long before the end ‘of the season, 
