THE FOOL) FISHES. 599 



THE DISAPPEARANCE OF THE FOOD OF FISHES. 



In 1871-2, vigorous investigations were carried on, dredging the sea bottoms from many 

 points along the coast, from which it was ascertained that great quantities of animal forms 

 existed there, throughout various depths. Fortunately, as early as 1863, Prof. Baird had 

 dredged in the vicinity of Woods' Holl, when the diminution of the food of fishes had not 

 become manifest. As a general result, it was found that the amount of invertebrate life was 

 quite unchanged in 1871, as compared with the earlier years back to 1863. Acres of mussel- 

 beds were found, and other forms swarmed the ocean bottom. On dredging at distances even 

 of twenty miles out seaward, buckets of water came up rilled with animal life — sea-stars, sea- 

 urchins, sea-shells, etc. The alleged circumstance of the diminution of food as a cause of the 

 decline in the numbers of food fishes is, therefore, of little weight. 



The second alleged cause, that of change of abode on the part of fishes, was found by 

 investigation to have little or no weight. 



Thirdly, disease as a cause, or atmospheric agencies. Instances have occurred where 

 large numbers of fishes have come ashore from death by some unexplained cause. In these 

 cases, it is customary to attribute their death to subaqueous eruptions, whereby sulphuretted 

 hydrogen is thrown up, killing the fishes that are near it. 



The agency of cold is often put forward as a cause, especially among the Tan tog. A 

 very low tide occurred during a cold spell, when large numbers of Tautog were killed and 

 thrown ashore in large numbers on Block Island, and along the southern shores of Massa- 

 chusetts and Rhode Island. We have seen this effect produced in the semi-tropical waters 

 of Florida Grulf, when the temperature became, as a very exceptional circumstance, about 

 50°. The fishes, accustomed to a much higher temperature, died, and were thrown on shore 

 in variety. 



"The fourth cause," says Prof. Baird, "is one as alleged, the ravages of predaceous 

 fishes, I am quite satisfied, is worthy of serious consideration, the principal offender in this 

 respect being the Blue-fish." The enormous voracity of this fish, running in small shoals or 

 bands, as they do, is productive of a wholesale slaughter, not outdone by any other species. 

 The Blue-fish is the perfection of form and graceful build — a fleet cutter, in the sense of fast 

 yachts. A voracious fish, with such capacity for offensive warfare, or rapid foraging, is a 

 terror to the smaller fishes that run in shoals for protection. 



The Blue-fish is a pelagic, or wandering species, characterized, as Prof. Baird says, by a 

 voracity and bloodthirstiness which, perhaps, is not equalled in the Animal Kingdom. The 

 fish seems to live only to destroy, and is constantly employed in killing and chopping up 

 anything that comes in its way that it can master. As some one has said, it is an animated 

 chopping-machine. Sometimes, among the immense schools of Menhaden, Blue-fish are seen 

 biting off tails or heads, and slashing in all directions in mere wantonness, seemingly leaving 

 in their trails the elements of the bloody battle-field. 



The Blue-fish, so called mostly, but known as Horse-mackerel, Skip-jack, Snap-mackerel, 

 Green-fish, White-fish, in various parts of our coast, is technically known as Pomatomus 

 saltatrix (Linn.), Gill. 



This fish is one of the most common and well known of American species, although, for a 

 time, its absence north of Cape Cod for a period, until about 1850, or, more correctly, its 

 scarcity in the eastern portion of Massachusetts Bay, was the means of the people of that 

 region and time having no practical acquaintance with it. Its value as a food fish in itself is 

 no mean item, but its bearing on the relations of our other food fishes is of the utmost impor- 

 tance. Its geographical distribution is very extended. Prince Maximilian says it extends to 

 Brazil. It is also seen on the Canaries' waters. It is noticed in the Mediterranean, in the 

 waters of New Holland, in the West Indies. The New Hampshire coast is nearly its northern 

 habitat, though it is reported as being seen at times as far north as Nova Scotia. It is emi- 

 nently a pelagic fish, which explains, in one way, its great distribution. The trimness and 

 celerity, as well as piratical dash of this species, recalls the rakish and fleet buccaneer craft, 



