PART XII. 
THE RIVER FISHERIES OF THE ATLANTIC STATES. 
1.—THE RIVERS OF EASTERN FLORIDA, GEORGIA, AND SOUTH 
CAROLINA. 
By MARSHALL McDONALD. 
1. SAINT JOHN’S RIVER, FLORIDA. 
DESCRIPTION OF THE RIVER.—The extreme sources of the Saint John’s River lie south of the 
twenty-eighth degree of north latitude. It trends north and south, and, gathering accessions from 
a hundred lakes, finally discharges its waters into the Atlantic Ocean under latitude 30° 30’. Its 
general course is from south to north. Like the Gulf Stream, therefore, it carries the warmth of 
the south to colder latitudes, in which respect it differs entirely from the other principal streams 
of the Atlantic slope, all of which run south and east, having their sources north, among the mount- 
ains, and carrying down to their lower reaches water of a lower temperature than that of the sur- 
rounding locality. This is especially true in the spring and early summer, when we find the tem- 
perature of these streams progressively diminishing as we ascend to their headwaters. The data 
are not at hand to furnish a tabular statement in proof of this progressive rise of temperature as 
the headwaters of the Saint John’s are approached, because records are only kept at one point—Jack- 
sonville; but the course of the river from south to north clearly shows that such must be the case. 
From the records of the signal office at Jacksonville we have obtained a connected series of ob- 
servations* of the temperature of the river for the years 187374, 187778, 1878~79, and 1879~’80. 
An examination of these tables shows that the river temperature passes below 60° about the 
1st of December, not again rising above that degree until the middle or end of February.t Coin- 
cident with this period of low temperature the shad run begins, the fishing season being at its 
height in February, when the temperature reaches 60°. A comparison of these observations with 
those for other rivers shows that though the shad season on the Saint John’s differs widely in time 
from that on more northern streams, yet it occurs under similar conditions of water temperature ; 
in other words, the time of the occurrence of shad in any river appears to depend solely upon the 
* For tables see Section I, Natural History of Aquatic Animals, pp. 600, 601. 
tIn 1871 William Dempsey bought shad at New Berlin, on the Saint John’s, He found that the average monthly 
catch per net was, in December, 82.6; in January, 413; in February, 619; and in March, 207. This indicates that from 
the latter part of January to the end of February is the period of the greatest abundance of shad iu this river. 
613 
