36 DEPARTMENT OF GAME AND FISHERIES No. 9 



Conservation Department, shows that the culture and distribution of one or all 

 of the above species are being carried on. This indicates with what care and 

 discretion their removal should be exercised and controlled. Fortunately their 

 culture is not required at the present time in Ontario, but in order to avoid 

 such a circumstance their exploitation commercially or otherwise is being 

 prevented. 



Pound Netting in Lake Erie 



A second season was spent in studying the pound-net situation in Lake 

 Erie in order to determine the mesh of netting in the crib which v/ould release 

 the largest number of immature fish, which would reduce or entirely eradicate 

 the sorting of fish, that is, the legal from the illegal-sized, and which would 

 prevent gilling of legal-sized fish in the crib or retainer. 



Seven experimental nets were set, and each of these was controlled on either 

 side by a commercial net in current use, that is, one having a 2-inch mesh through- 

 out the crib. In each case, the experimental nets were the same as the com- 

 mercial nets, with the exception that each of the former had twine of varying 

 mesh set in the backs of the cribs, namely, l^^-inch, 23^-inch, 23/^-inch, 23^-inch, 

 3-inch, and 334-inch. One crib was made up of mesh similar to that used in 

 the back and sides of the trap nets in the State of Ohio and instituted by law for 

 1929. This was done merely for comparative purposes and not with the remotest 

 desire or object of recommending such nets for the Canadian portion of Lake 

 Erie. 



Each day an accurate record was made of the fish retained in the cribs of 

 the seven experimental nets and the eighteen controls as follows: species, weight, 

 size, number, percentage gilled, and total catch. The daily records were arranged 

 diagrammatically so that each record corresponded to the position of a net 

 relative to each of the others. 



The measurements given above are for new twine. When the twine is 

 tarred and subjected to the action of water it shrinks from 18 to 25 per cent. 

 The true size of the mesh when in use was, however, recorded. 



Until the results are gone over very carefully, no definite conclusion can 

 be stated, but it would appear that a l^^-'mch mesh in the crib is the most 

 satisfactory from the standpoint of the preservation of immature fish. On the 

 other hand, a minimum number is gilled in the l^^^-inch and 2-inch mesh; but 

 these meshes retain fish of all sizes, and the sorting of fish with its innumerable 

 abuses creeps in. A crib which allows immature fish to escape and thus provides 

 a minimum sorting is looked upon with favour by the Fish Culture Branch. 



Investigations on the Georgian Bay 



During the past summer our investigations on the Georgian bay centred 

 around (1) the use of lake trout hooks by commercial fishermen and their 

 detrimental effects, if any; (2) the justification for establishing new lines 

 protecting inshore waters and prohibiting commercial fishing in the areas enclosed 

 by such lines; (3) the effect of the operation of pound nets on the south shore of 

 Georgian bay on game fish and commercial fish, such as lake trout, which are 

 prized by anglers in that section. 



Without more complete findings it is impossible to state that licensed trout 

 hooks are taking an undue proportion of immature trout. It is also impossible to 

 state at this juncture whether bait fishermen engaged in hook fishing are damaging 

 the food supply of the trout by removing quantities of bait-fish. 



