374 



BULLETIN OF THE BUREAU OF FISHERIES 



under my direction with the trout and whitefish nets off Alpena, Mich., for the 

 special purpose of determining the inshore range of chubs; (4) the pound nets set 

 alongshore in shallow water. 



1. Catches of 1%-inch bait nets. — Record 44 shows that such a net set in 31 

 fathoms at Harbor Beach, Mich., yielded a catch, 21 per cent of which was of small 

 longjaws. On the other hand, lifts of identical nets in 30 fathoms off Alpena on 

 September 8, 1917, and September 16, 1919, were examined by me without revealing 

 more than a single specimen of this species (record 10); and in the lift made off 

 Cheboygan, Mich., on October 15, 1919 (record 3) relatively few examples were 

 found. The evidence from this source is scant and inconclusive and concerns only 

 the immature fish that may be taken in gill nets of small mesh. In what quantities 

 these small longjaws are taken in bait nets, at what seasons, and under what con- 

 ditions are matters of prime interest. Record 44 shows that they made up 21 

 per cent of one haul, but in general it is known only that large numbers of small 

 fish of some sort are taken daily to bait trout hooks. If a considerable percentage 

 of these immature fish is longjaws or other species of commercial value when adult, 

 their continued destruction may reduce greatly the supply of marketable fish of the 

 species caught. The matter is worthy of further investigation. 



2. Lifts of JiYi-inch gill nets set for trout and whitefish. — I found large longjaws 

 occasionally at Alpena, Mich., in September, 1917, gilled in 4^-inch trout nets 

 lifted from 20 to 30 fathoms (record 11). Records of Alpena fishing tugs examined 

 by me suggest that similar large fish are caught virtually throughout the season in 

 these nets (record 40). Record 5 shows them taken daily during the last two weeks 

 of September on rock bottom in 12 to 15 fathoms at Rogers, Mich. Record 45 

 shows similar fish in 20 to 30 fathoms at the Duck Islands, Ontario. Record 46 

 shows them during the summer off Gore Bay Lighthouse in the North Channel in 

 20 to 35 fathoms. Record 47 indicates that they are caught in winter at similar 

 depths. The fish recorded under Nos. 5, 45, 46, and 47 were not seen by me, but their 

 size indicates that they were longjaws; only the largest individuals of the species 

 are gilled in nets of this mesh. 



The specimens collected by me from 14 to 30 fathom lifts of 43^-inch trout nets 

 at Alpena (records 9, 14, 23, 31, and 39) were small longjaws. They were not gilled 

 in the usual sense of the word but were caught by their jaws becoming entangled in 

 the meshes of the nets, so that their presence in the nets must be regarded as acci- 

 dental. It is probable that they occur in shallow water in larger numbers than is 

 indicated by their occasional capture in gill nets of large mesh. 



3. Lifts of 2%-inch gill nets set in less than 30 fathoms. — These nets were set in an 

 attempt to determine whether gill nets of suitable mesh set on the same grounds as 

 the 43^-inch trout nets referred to in the preceding paragraph would show longjaws 

 in greater abundance than is indicated by their accidental capture in the trout nets 

 themselves, or whether they occurred in localities in which the trout nets did not 

 reveal them. The nets were lifted off Alpena as follows: September 17, 1917, 13^ 

 miles SE. by S. of the can buoy in 15 fathoms with 4K-inch whitefish nets; Sep- 

 tember 19, 1917, 23 miles SE. by E. H E. of the can buoy in 30 fathoms with trout 

 nets; September 26, 1917, 13 miles SE. by S. of the city in 17 fathoms; November 2, 

 1917, 7 miles E. NE. of the can buoy in 15 fathoms on honeycomb rock. In each 



