70 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
hue, and its smell was “like that of rotten eggs.” This was diffused 
gradually around the lagoon, and passed into the ocean; and within 
twenty-four hours every fish, coral, and mollusk in the part impregnated 
with this discoloring substance died. So great was the number of fish 
thrown on the beach that it took three weeks of hard work to bury them 
in a vast trench dug in the sand. 
It is supposed that this water was impregnated with hydro-sulphurie 
or carbonic acid. The statement is made that the corals and shells 
were deeply corroded, the corals, especially, being in many places worn 
down tothe solid base. For along time after the catastrophe there 
were no signs of life in the lagoon. 
Precisely to what cause we are to cine the destruction of fish in 
the summer season, in the Gulf of Mexico, it is impossible to say. -Here, 
without any apparent reason because of change of temperature or other 
physical condition, for a period of weeks together, myriads of fish, of all 
species, are found dying or dead, so much so that: they drift ashore in 
vast numbers, threatening to create a pestilence. It appears that the 
cause, whatever it be, is disseminated in the water, as smacks loaded 
with living fish in their wells, intended for the markets of Key West, 
Cuba, or the north, when entering certain zones éxperience the loss of 
their entire cargo. It is possible that the fatality is caused by some 
algous or fungous plant, which exercises a deleterous effect upon animal 
life. The statement that the zones of dangerous water are differently 
colored from the.main body, would strengthen this impression. One 
explanation is that the water from the Everglades, pouring intothe Gulf, 
in some way exercises a deleterious influence. 
As a general rule, of the fishes which perish from one of these causes 
or another, no matter how great the mass, it floats at the surface of the 
sea until decomposed and wasted, leaving but little inthe way of defi- 
nite remains. 
In regard to the agency of physical causes in destroying immense 
numbers of fish simultaneously, under circumstances to involve their 
being imbedded and their skeletons thereby preserved, numerous illus- 
trations can be adduced in modern times, as we have already shown. 
The eruptions of voleanoes along the sea-coast frequently discharge 
immense bodies of acid or heated waters into the sea that poison every- 
thing around them, the fish being imbedded in the mineral matter 
which accompanies the discharge, or covered up by the ordinary 
tides, or by the extraordinary currents produced by the same out- 
break. 
Another very frequent and important natural source of destruction 
to which we have just referred is in the sudden cooling of tropical wa- 
ters by the ‘“‘northers.” These are frequently observed in the Gulf of 
Mexico, where, in the winter especially, the waters are frequently 
changed abruptly and to a very marked degree by the persistent blow- 
ing of an intensely cold and long continuéd wind from the north. ‘This 

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