THE REAPPEARANCE OF THE TILEFISH. 
323 
dredge was used 47 times. It is fortunate that these investigations were made in 
1880 and 1881, since they furnished definite data respecting tiie i)hysical and biological 
conditions of a tract of the sea bottom which in the sju’ing of 1882 became the scene 
of widespread devastation. 
While Captain Collins was collecting his data, the Fish liaivlc, which had taken 
a few tiletish in 1880, and had found them very numerous in 1881, was continuing her 
deep-sea explorations under the direction of Professor Verrill. During August, Sep- 
tember, and October, 1882, five trips were made to the tilefish grounds, and the dredge 
was lowered 4(1 times. The definite information relative to the life on the sea bottom, 
which Professor Verrill had been able to secure during the summers of 1880 aud 1881, 
now became of great value, since it enabled him to report on the general faunistic 
changes which had affected this area, to measure the extent of the destruction of 
oceanic life, and to give an intelligent reason therefor. 
In the report for 1882, he writes : 
Oue of the most peculiar facts couuected with our dredging this season (1882) was the scarcity 
or absence of many of the species, especially Crustacea, that were taken in the two previous years, in 
essentially the same localities aud depths, in vast numbers, several thousand at a time. 
In another article (Physical characters of the portion of the continental border 
beneath the Gulf Stream, explored by the Fish Hawh, 1880 to 1882), Professor Verrill 
describes the rapid iucline of the sea bottom beyond the 100-fathom line, “usually as 
steep as the side of a great mountain chain, and about as high as Mount Washington, 
New Hampshire.” He further Avrites: 
The bottom along the upper part of this slope and the outermost portion of the adjacent 
plateau, in 65 to 150 fathoms, and sometimes to 200 fathoms or more, is bathed by the waters of the 
Gulf Stream. Consequently the temperature of the bottom water along this belt is decidedly^ higher 
than it is along the shallower part of the plateau near the shore, in 25 to 60 fathoms. * * * yve 
may therefore call the upper part of the slope, in about 85 to 150 fathoms, the “warm belt.” — ( Report 
U. S. Fish Commission for 1882, p. 279.) 
It Avas along this Avarm belt that many animals characteristic of tropical or sub- 
tropical fauna were dredged in 1880 and 1881, and Professor Verrill states: 
lu fact, this belt is occupied by a northern continuation of the southern or West Indian Gulf- 
Stream fauna * * * that could not exist there if the Gulf Stream did not How along this area at 
the bottom, both in winter and summer. 
The tilefish, whose relatives are known to be tropical, doubtless belongs to this 
warm-water fauna, aud the de.structiou of 1882 was exidaiued by Professor Verrill when 
he wrote, in October of that year : 
It is probable, therefore, that the linding of vast numbers of dead tiletish lloatiug at the surface 
in this region last winter was connected with a wholesale destruction of the life at the bottom, along 
the shallower part of this belt (in 70 to 150 fathoms), where the southern forms of life aud higher 
temperature (17° to 52°) are found. This great destruction of life was proljably caused by a A-ery 
severe storm that occurred in the region at that time, which, l)y agitating the bottom water, forced 
outward the very cold water that even in summer occupies the wide area of shallower sea in less than 
60 fathoms along the coast, and thus caused a sudden lowering of the teuiijerature along this narrow 
warm zone, where the tiletish and the Crustacea referred to were formerly found. 
The warm belt is here narrow, even in summer, and is not only bordered on its inner edge, but is 
also underlaid in deeper water by much colder water. In fact, the bottom water inshore is probably 
below 32° F. in winter where the depth is 20 to 10 fathoms. In August this year (1882) we found the 
temiierature 37° F., south of Cape Cod, in 55 to 60 fathoms. It is evident, therefore, that even a mod- 
erate agitation and mixing up of the warm aud cold water might in winter reduce the temperature 
so much as to practically obliterate the warm belt at the bottom. Rut a severe storm, such as the one 
