XXII REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



these fishes were to be found in an increased abundance, such as would 

 result from the overlapping of the normal supply of any part of the 

 coast by that from a different region. The fish were certainly not displaced 

 iu an easterly direction ; and to the west of Narragansett Bay their 

 numbers, though perhaps not diminished to the same extent as east of 

 it, were decidedly less than formerly. 



'Thirdly, disease or atmospheric agencies. — The question of epidemic 

 diseases among fishes is sometimes suggested by finding large numbers 

 coming ashore, at times with and at others without any assignable 

 cause. Occasionally this may be referred to volcanic exhalations, which 

 charge the water with sulphuretted hydrogen gas or other noxious sub- 

 stances, and thus produce death. Where no positive cause can be indi- 

 cated, the occurrence of some form of disease is frequently assigned as the 

 reason. 'It is stated, for instance, that in the last century the blue-fish about 

 Nantucket, then in great abundance and of enormous size, so large 

 indeed that thirty of them would fill a flour-barrel, were attacked by a 

 disease which destroyed them in large numbers j and that the Indians 

 of the island were nearly exterminated at the same time, either by 

 sharing in a common attack, or by eating the diseased fish. In the 

 course of time the blue-fish again returned to the Nantucket waters, 

 although of much smaller size than formerly represented; but the In- 

 dians never recovered their ground, their number being now extremely 

 limited. 



The agency of cold is also given as producing occasionally great 

 mortality, especially among the tail tog. A very cold spell, occur- 

 ring at low tide some years ago, is said to have killed the tautog 

 in such numbers that hundreds of tons were thrown ashore at Block 

 Island and along the southern shores of Rhode Island and Massachu- 

 setts. This fact appears to be well attested, and, in all probability, 

 may have had a decided influence, and similar facts, though on a much 

 smaller scale, have been adduced in reference to the young scup in the 

 late autumn, but this cannot have material influence on the number of 

 old scup, as may be the case with the striped bass and tautog, both of 

 which are known to be winter residents of these shores. Similar facts 

 have been observed even as far south as the Gulf of Mexico, where the 

 occurrence of a "norther" not unfrequently produces more or less 

 mortality by chilling the water. 



The fourth cause of decrease, as alleged, namely, the ravages of 

 predaccous fishes, I am quite satisfied is one worthy of serious con- 

 sideration, the principal offender in this respect being the blue-fish. 

 No one who has spent a season on the coast, where this fish abounds, 

 can fail to have been struck with its enormous voracity, aud the amount 

 of destructiveness which it causes among other kinds of fish. Wherever 

 it appears in large numbers it is sure to produce a marked effect upon 

 the supply of other fishes, either by driving them away from their 

 accustomed haunts or by destroying them in large quantities in any* 



