108 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [18] 



the fish. This is probably, as he supposes it to be, " white-bait" or the 

 young of the sea herring, Glupea harengus. It is known as "eye-bait" 

 to the Canadian fishermen. 



Captain Merchant tells me that when mackerel are found with "red- 

 seed" in their stomachs fishermen are sure that they are on the right 

 fishing grounds. 



I am told by Captain Collins that it is common for many of the Amer- 

 ican fishermen to consider it a good sign of mackerel when they see 

 floating seaweed, more especially eel grass, "chopped up," i. e., cut 

 into short pieces, which they think is done by these fish. Perhaps 

 there may be a good reason for this supposition, since the mackerel, while 

 feeding on the diminutive shells with which the weeds are covered, may 

 also bite the latter in two. The presence of gannets is also considered 

 a good sign of mackerel. 



In England the food of the mackerel is called the "mackerel mint," 

 and this is said to consist at certain seasons of the year of the sand- 

 lants and five other fish, especially the herring and the sprat, while 

 they have also been observed to devour, in the summer months, minute 

 crustaceans, the swimming larvse of tape-worms, and the embryos of the 

 small spiral shell of the genus Eissoa, which, in its adult state, is found 

 in great abundance upon seaweed. It was probably some animal of this 

 kind which was referred to by Captain Harding in the statement above 

 quoted, concerning the abundance of red seed about Boone Island. Mr. 

 J. F. Whiteaves has recorded a similar habit for the mackerel of the Gulf 

 of Saint Lawrence.* 



Professor Hind has pointed out certain relations which exist in the 

 Gulf of Saint Lawrence between the mackerel and the lant, or sand-eel, 

 which appears to be one of its most important articles of diet in these 

 waters. I quote here in full his observations upon this subject, and also 

 his views upon the relations of currents and tides to the presence of 

 mackerel food, and the constant movements of the schools of fish: 



" The movements of the mackerel, like those of the cod, and indeed 

 of most species of fish, are determined at different seasons of the year 

 by the geographical position of its food ; and the first important kind 

 of food which appears to lure the mackerel inshore, after spawning in 

 the Gulf of Saint Lawrence, is the launce or sand-eel. 



"The relation of the launce or sand-eel [Ammodytes americanus) to 

 the mackerel is very much greater than appears at the first blush, and 

 resembles the relation of the herring to the cod in general, and in par- 

 ticular the relation of the so-called Norwegian 'Sull cod,' or launce 

 cod, to this widespread and important bait-fish. The approach of the 

 launce to the coast in spring is most probably the cause why the so- 

 called spring cod fishing suddenly ceases on many banks and shoals, 

 commencing again at difl:erent localities two and three weeks later. 



* Report on the second deep-sea dredging expedition of the Gulf of Saint Lawrence, 



1872. 



