EFFECTS OF TAGS ON THE FISH 



LITERATURE CITED 



Although the study was conducted to 

 compare the corrosion resistance of the two 

 types of tagging pins, observations Jilso 

 were made on the effects of the tags and 

 the tagging technique upon the opercula on 

 which the tcigs were fastened. 



Damage to the operculum occurred in 

 almost all the haddock which survived more 

 than two weeks after tagging, varying from 

 a mild inflammation to severe ulceration. 

 In £01 extreme case, extensive necrosis 

 occurred which resulted in loss of the tag. 

 This tag was recovered intact from the bot- 

 tom of the tank. When examined, the fish 

 was found to have a raw hole about 3/4 

 inches in diameter where the tag had been 

 applied. 



On seven fish the inner disc was par- 

 tially or completely grown over with tissue, 

 but no fish had only the outer disc grown 

 over. On one fish both inner and outer 

 discs were grown over. The concealment of 

 Petersen discs by overgrowth of tissue may 

 be a factor contributing to rapidly dimin- 

 ishing returns from field tagging (Rounse- 

 fall 1941). 



ANONYMOUS 

 1947. 



Fabrication of U.S.S. stainless 

 and heat resisting steels. U.S. 

 Steel Corp., Carnegie-Illinois 

 Steel Corp., Pittsburgh-Chicago, 

 136 pp. 



CALHOUN, A. J., D. H. FRY, JR., 

 AND E. P. HUGHES 

 1951. Plastic deterioration and metal 

 corrosion in Petersen disc tags. 

 Calif. Fish and Game 37(3): 301- 

 314. 



FORRESTER, C. R. , AND K. S. KETCHEN 

 1955. The resistanr o salt water 



corrosion of .arious types of me 

 metal wire used in the tagging 

 of flatfish. Jour. Fish. Res. 

 Bd. Can. 12(1): 134-142. 



ROUNSEFELL, GEORGE A. 



1941. Field experiments in selecting 

 the most efficient tag for use 

 in haddock studies. Trans. 

 Amer. Fish. Soc . 71:228-235. 



Black granular tissue which sur- 

 rounded the pin for a radius of about 1/4 

 inch was seen on seven fish, five of which 

 had been tagged with nickel pins. 



Opercular ulcerations occurred on 

 eight fish which were tagged with nickel 

 pins and on twelve which were tagged with 

 stainless steel pins. The small increase 

 in ulceration associated with the stainless 

 steel pins may have been a result of the 

 stiffness of these pins. They are slightly 

 more resistant to bending than are the 

 nickel pins. The tagger's unfamiliar ity 

 with the new pin materieil caused him to 

 exert more pressure when twisting the pins 

 and this resulted in tight tags. Pressure 

 from the tag discs probably caused a sore 

 to develop beneath the discs which ulti- 

 mately led to a deep ulceration. This 

 hypothesis cibout the causes of the tagging 

 wounds is supported by the effects of three 

 tags which had been loosely fastened. One 

 fish had been tagged with a stainless steel 

 pin and developed only a slight sore under 

 the discs. The other two fish had been 

 tagged with nickel pins; one developed no 

 sore under the discs, the second developed 

 only minor sores. 



