MORTALITY OF FISHES, WEST COAST OF FLORIDA. 13 



mortality, 3'et certain possible causes are shown not to be operative. 

 Furthermore, significant circumstances in the case of 1916 and of 

 previous years, records of similar disasters in other parts of the 

 world, and opinions of representatives of the numerous sciences con- 

 cerned, are brought together here as the basis of discussion and also 

 for further work, if there should be a recurrence of the phenomenon. 



The mortality occurred in 1844, 1854 (Ingersoll, 1882), and a very 

 severe attack was reported in January, 1878. In August, September, 

 October, and November, 1880, it occurred again, but in relatively 

 milder form. The last two instances are said to have been preceded 

 by earthquiikes. In July, 1882. the plague returned; in this case it 

 may be connected with the tilcfish disaster, which occurred at the 

 edge of the continental shelf south of Nantucket along the 100- 

 fathom line. In the summer of 1908 a similar mortality destroyed 

 the spouge beds along the keys between Key West and the mainland. 

 In 1010. as above stated, the mortality Avas exceedingly severe be- 

 tween Boca Grande Pass and Big Marco Pass. The older reports are 

 meager and not based on direct observations; in some cases inverte- 

 brates — chiefly sponges and king crabs — were predominant, in others, 

 sharks and porpoises. It may, then, be assumed that the reports 

 furnish no 'reliable indication of exact conditions. 



The causes suggested are (1) water from the Everglades charged 

 with tannin and products of decomposition of palmettoes and man- 

 groves; (2) extraordinary abundance of Peridinium known to have 

 occasioned the death of fishes in different parts of the world; (3) a 

 disease, fungoid, parasitic, or bacterial; (4) dilution of the water by 

 unusually heavy rains; (5) an issue of gas, volcanic or natural; and 

 (6) earthquakes or seaquakes. 



FOUL AVATER FROiSI THE EVERGLADES. 



1. A hypothesis that has been advanced repeatedly is that water 

 from the Everglades, charged with tannin and the products of decay 

 in vegetation, is brought doAvn by the rivers and kills fishes. It may 

 be said Avith sufficient certainty that this is an impossible explana- 

 tion. For there are no a priori grounds for assuming that the Ever- 

 glade water is poisonous; nor is there any material evidence of such 

 a condition. No fresh-water fishes were killed; life in the ri\^er was 

 normal ; and fishes are known to live m the Everglades. The sporadic 

 appearance of the phenomenon casts doubt on the possibility of such 

 an explanation. And, finally, it seems quite impossible to belicA^e 

 that the volumes of the rivers are sufficient to account for such a 

 widespread distribution of the mortality. It may be, how^ever, that 

 the accumulation of the riA^er load as a decaying organic sediment 



