364 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



feet) . Burbot were absent from shallow water in July and August, and appeared to be 

 concentrated at intermediate depths (81-100 feet in July and 71-110 feet in August). 

 In September and October they apparently were concentrated in depths beyond 100 feet. 

 The changes in the average number of fish per net at the various depths for the months, 

 July-October, suggest a general tendency for the burbot to move toward deeper water. 

 The regular increase from July to September in the catch from 71-80 feet provides an 

 exception to this general trend. The seasons' averages show a scarcity of burbot at 

 depths of less than 71 feet and the greatest abundance at intermediate depths (71-100 

 feet), with the abundance in deep water (more than 100 feet) about half that at 

 intermediate depths. 



Table 35. — Number of burbot per lift of pound nets and deep trap nets in northeastern Lake Michigan (ports 



of Manislique, Epoufette, and Naubinway), 1931-1932 



[Number of lifts in parentheses] 



The data on the bathymetric distribution of the burbot in northeastern Lake 

 Michigan (table 35) provide little evidence of any extensive vertical movements. 

 Characteristic of the averages for each month appeared to be an inshore concentration 

 at 41-60 or 61-70 feet (except in August when only one lift was observed from a depth 

 of less than 70 feet), a reduced abundance at intermediate depths up to 101 feet (111 

 feet in June), and a second concentration at 101-110 feet or more than 110 feet. The 

 average catches in October were greater than those in other months from every depth 

 but 91-100 feet. (The average catch from 101-110 feet was the same in July and 

 October.) The seasons' averages show an increase in the number of burbot from 0.8 

 in shallow water (less than 41 feet) to a maximum of 5.1 fish per lift at 61-70 feet. 

 The average catch per net varied between 1.8 and 3.3 fish in depths of 71-110 feet 

 and rose to 4.3 in water more than 110 feet. 



WHITE SUCKER AND LONG-NOSED OR STURGEON SUCKER 



Separate counts of white suckers (Catostomus commersonnii) and long-nosed or 

 sturgeon suckers (C. catostomus) were obtained for only a limited number of lifts in 

 the Alpena-Ossineke and Saginaw Bay areas of Lake Huron. The available data 

 indicate that white suckers were most numerous in depths of less than 81 feet; only 

 one individual was captured in deeper water (in 101-110 feet). Long-nosed suckers 

 also were most plentiful inside the 81-foot contour, but were taken in fair numbers at 

 greater depths. No long-nosed suckers were captured in depths beyond 110 feet. 



