PROTECTING THE UNDERSIZED TROUT 



By G. H. Thomson, 

 estes park fish hatchery, estes park, colorado. 



I desire to thank the Society at this time for the assistance 

 given nie at the Congress which convened last September in 

 Washington by the indorsment of the recommendations I 

 offered for the protection of the undersized trout. 



I desire also to state a few of the facts which led me to 

 take up the cause of the small fish, and which from my own 

 personal investigation convinced me beyond a reasonable 

 doubt as to the effect of grasping an undersized trout (which 

 the law requires shall be returned to the stream) with a dry 

 hand, when removing from the hook. 



One year ago, I desired to have a couple of large trout 

 to place in one of my hatching troughs, in order to compare 

 them with the records; and also to show the beauty of the 

 trout in their natural state. I caught, with a dip net, two 

 yearling eastern brook trout from the stream that runs in 

 front of the hatchery, and removed them from the net to a 

 bucket of water by grasping them with a dry hand. Imme- 

 diately my hand was covered with the slime from the backs 

 of the fish. Several days after placing the fish in the hatch- 

 ery, I noticed that a white fungus growth had begun to form 

 upon their backs where I had grasped them with my hand. 

 I watched them closely from day to day, and found that the 

 fungus was increasing. I had observed fish in this condition 

 before but did not have them where I could follow them. 



When I have any trouble with my fish in the hatchery I 

 always use salt in the water, as salt is a disinfectant. So I 

 then prepared a strong solution of salt water in a pan and 

 placed the fish in it, one at a time ; one of them was overcome 

 by the salt in three minutes, and I removed it to spring water, 

 where it revived in ten minutes ; the other one I held for five 

 minutes in the salt solution, and it recovered in fifteen 

 minutes time. 



