WHITEFISH FISHERY OF LAKES HURON AND MICHIGAN 



387 



bined. The data do not, however, support the complaint that the deep-trap-net fishery 

 was extremely harmful to the pound-net fishery in 1931. It is true that the total pro- 

 duction in pound nets was less in 1931 than in 1930, but the decline was the result of 

 reduced fishing intensity. The average catch of whitefish per lift of pound nets was 

 approximately 10 pounds greater in 1931 than in 1930. 



Although the average lifts of whitefish in deep trap nets in 1931 were 2.3 times those 

 of pound nets, this advantage depended only on the greater depth of water in which 

 deep trap nets were fished. The effect of the depth of water on the size of the lift is 

 brought out by the comparison of the lifts of whitefish in shallow pound nets, deep 

 pound nets (more than 50 feet of water) , and deep trap nets (table 51 1 . There was little 

 difference between the size of the lifts of deep pound nets and deep trap nets, but both 

 took more than 8 times as many fish per lift as shallow pound nets (less than 50 feet 

 of water). It is obvious, therefore, that any indictment of the deep trap net in Door 

 County waters as a dangerously effective gear must apply also to deep pound nets. 44 



Further conclusions based on observations of pound nets and deep trap nets in 

 Door County waters are summarized as follows: 



(1) The sorting of fish was more difficult in deep trap nets than in pound nets. 

 However, less sorting was necessary with deep trap nets than with pound nets which 

 ordinarily had 2-inch mesh (stretched measure). Very few illegal whitefish (legal size 

 limit, 13 inches, total length, at the time of the investigation) wore seen in deep trap 

 nets, the mesh of which ranged from 3% to \ x /-> inches. On several occasions small 

 fish were seen to escape through the meshes as deep trap nets were lifted. 



(2) Very few gilled fish were observed in deep trap nets, and most of the fish 

 gilled were of legal size. A 3%-inch-mesh net allows the escape of whitefish of 13 

 to 13VO inches, total length, and smaller; 4%-inch meshes release whitefish about 16 

 inches long, and smaller. 



(3) The observations did not support the contention that illegal whitefish brought 

 to the surface in deep trap nets die. Small whitefish and herring were seen to pass 

 through the bottom of the trap nets when they reached the surface, apparently uninjured 

 and certainly not bloated. 



REGULATIONS RECOMMENDED FOR THE DEEP TRAP NET IN 

 WISCONSIN WATERS 



The investigating committee submitted the following recommendations for the 

 regulation of the deep trap net in Wisconsin waters (almost entirely direct quotation 

 from report) : 



1. The size of the mesh in the lifting pot must be not less than 4*/2 inches but the 

 side of the pot where fish are bagged may be of smaller mesh. 



2. The length of the lead shall be not more than 50 rods. 



3. A buoy must be attached to every anchor and each buoy must have a flag 

 attached to it, extending not less than 30 inches above the surface of the water. 



4. The shortest distance between strings of trap nets or between trap nets and 

 pound nets shall be not less than one-half mile. A trap net as here defined refers 

 to any part of the net constructed of webbing and includes the pot, tunnel, heart, and 

 lead (not the anchors, ropes, buoys, and flags). 



44 Both gears can operate on the concentrations of whitefish at depths of 50 or 60 feet. Attempts of deep-trap-net fishermen to locate white- 

 fish in deeper water (ca. 100 feet'l were unsuccessful. 



