CORROSION RESISTANCE OF FISH TAGGING PINS [Marine Biological Laboratoryj WOODS HOLE, MASS. SPECIAL SCIENTIFIC REPORT- FISHERIES No. 262 UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE ( EXPLANATORY NOTE TTie series embodies results of Invearlgatlons, usually of restricted @uope, intended to aid or direct management or utilization practices and as guides for administrative or legislative action. It is issued in limited quantities for official use of Federal, State or cooperating agencies and in processed form for economy and to avoid delay in publication. United States Department of the Interior, Fred A, Seaton, Secretary Fish and Wildlife Service, Arnie J. Suoraela, Commissioner CORROSION RESISTANCE OF FISH TAGGING PINS by Albert C. Jensen Fishery Research Biologist Bureau of Commercial Fisheries United States Fish and Wildlife Service Special Scientific Report — Fisheries No, 262 Washington, D. C. December 1958 The Library of Congress has cataloged this publication as follows: Jensen, Albert C Ci)riosinii rosistancc of K^h tiifr. illus. 27 cm. ( r. S. Fisli and Wilillile Seivkf. Six'oiiil scientitic report : tisheries no. 262) Bibliography : p. 4. 1. Fish tagging. i. Title. (Series) SH11.A335 no. 262 639.2 59-60033 Library of Congress The Fish and Wildlife Service series, Special Scientific Report — Fisheries, is cataloged as follows: U. S. Fish and Wildlife Service, Special scientific report : fisheries, no. 1- tWashington, 1949- no. illus., maps, dlagrs. 27 cm. Supersedes In part the Service's Special scientlflc report. 1. Fisheries — Research. SH11.A335 639.2072 59-60217 Library of Con^nress i2] ABSTRACT Aquarium-held haddock were tagged with nickel and Type 304 stainless steel pins to compare the corrosion resistance of the two metals. The stainless steel pins proved to be superior. CONTENT Page Conditions of the experiment Tanks 1 Fish 1 Method of tagging 1 Control pins 2 Fish survival 2 Results Nickel pins 2 On tagged fish 2 Controls 3 Stainless steel pins 3 On tagged fish 3 Controls 3 Discussion and conclusions 3 Effects of tags on the fish 4 Literature cited 4 Appendix Table A 5 Table B 6 CORROSION RESISTANCE OF FISH TAGGING PINS Wire or pins made of various metals, including silver, platinum, copper, and nickel, have been used extensively to fasten tags to fish. For some years nickel pins were used with Petersen discs to mark had- dock (Melanogrammus aeglef inus L.) in the Gulf of Maine (Rounsefell 1941) and on Georges Bank. When recovered many of them were corroded, suggesting that many tags may have been lost from the fish. To avoid this loss, stainless steel pins were con- sidered as a possible substitute. An experiment with tagged haddock was conducted in the Fish and Wildlife Service aquarium at Woods Hole to compare the cor- rosion resistsince of Type 304 stainless steel pins with that of the nickel pins used in the past. The metallic composition and dimensions of the two types of pins are shown in taible 1. CONDITIONS OF THE EXPERIMENT Tanks Six indoor aquaria each holding about 300 gallons were used in the experiment. Flowing sea water at the rate of four changes per day was supplied to the tanks from Great Harbor, on which the laboratory is located. The water temperature in the tanks was recorded with a Bristol recording thermometer* The average salinity of the water in Great Harbor is 32 parts per thou- sand, and because of the frequency of change the salinity of the aqu«irium water was pre- sumably the same. Fish The haddock used in the experiment were captured by an otter trawl on Georges Bank during Albatross III cruise 59, April 6-12, 1955. A total of 168 fish were transported to Woods Hole on board the ves- sel in wooden tanks supplied with running sea water. Haddock are delicate and difficult to maintain in aquaria. Four weeks were there- fore allowed for initial mortality and to acclimate the fish before the experiment began. Forty-three fish survived eind 36 of the strongest, ranging in size from 30 centimeters to 60 centimeters, were selected for use. Table 1. --Composition and dimensions of tagging pins — 1/ Stainless Steel Chromium 18. 7% Nickel 10.7 Molybdenum 0.22 Carbon 0.08 Titanium* 0.1 Niobium* 0.1 Iron 70.1 100.0 Length (in. ) 1.53 Diameter (in. ) . 035 Nickel Nickel 98. 5% Cobalt 0. 5 Silicon 0. 3 Manganese 0.2 Copper 0.2 Iron 0.1 Length (in. ) Diameter (in. ) *Spectrographic analysis _' Analyzed by National Bureau of Standards 99.8 1. 81 . 032 Method of Tagging The fish were tagged with Petersen discs on May 9 using the technique described by Rounsefell (1941) in which the pin is threaded through the center of one disc and then pushed through the operculum from the inside. The second disc is then threaded on the projecting point of the pin. The surplus part of the pin is cut off and the remainder twisted into a loop cind bent over with long-nosed pliers. To calm the fish while being tagged, they were placed in a tank containing 12 gal- lons of sea water to which one-half pound of ethyl carbamate (Urethane) had been added. After about one minute in the anesthetizing bath the fish began to float belly up, made only feeble swimming movements and were generally relaxed enough to per- mit tagging. On 18 fish the tags were fastened with stainless steel pins and on the other 18 fish the tags were fastened with nickel pins. Three fish tagged with stainless steel pins and three fish tagged with nickel pins were placed in each tank. Control Pins In addition to pins attached to the fish, two groups of control pins were set up to distinguish the effects of the raw harbor water, the aquarium water and the body fluids of the fish. A group of 10 stainless steel pins and 10 nickel pins were put in the aquarium water with the fish and a similar group was placed in the harbor. Half of these pins were bent as in tjigging and half were left straight to see if bending affected the resistance to cor- rosion. rising until it reached 70° F. on July 1. The last fish succumbed on July 12. These data are shown in table 2. Although 36 fish had been tagged, only 34 tags were recovered from fish dur- ing the course of thg. experiment . The tags which had fallen off two fish were later recovered from the bottom of the tank. When a fish died its tags and pin were re- moved intact and washed in fresh water. The tag number, the date and the condition of the tagging wound were noted. At the end of the experiment the control pins were removed from the tanks and the harbor and washed in fresh water. All pins were exam- ined under a binocular microscope for evidence of corrosion. Fish Survival RESULTS There was some mortality throughout the experiment, but 20 fish survived for eight weeks. All these died during the ninth week, probably from lethal water tem- peratures. Previous studies at Woods Hole have shown that haddock do not survive well at water temperatures higher than 65° F. The temperature in the tanks was 53° F. on May 9 and reached 65° F. on June 19, six _weeks later. The temperature continued Table 2. --Abstract of the experimental log Nickel Pins On Tagged Fish Date May 9 16 23 30 June 6 13 20 27 July 4 12 Water Temperature (degrees Fahrenheit) &3 54 57 59 60 62 67 69 70 70 Number of fish alive All the nickel pins were corroded except one pin that was on a fish which died the day after tagging. Most of the nickel pins were corroded where they passed through the operculum and were in contact with tissue. The degree of corrosion vaxied from minor (staining and shallow etching on the surface metal) to extensive (deep etching and weaken- ing of the metal). Two pins were partially worn through from abrasion by the tag discs, one was abraded by the inner disc, the other by the outer disc. 36 32 27 26 25 25 22 22 20 AU dead Three pins appeared sound on the surface but broke when bent, revealing a hollow corroded interior covered by a thin skin of apparently unaffected metal. This phenomenon has also been noted by Calhoun, Fry, and Hughes (1951) and Forrester and Ketchen (1955). In one case the nickel pin weakened and broke, allow- ing the pin head and inner disc to fall off the fish. The rest of the pin and the outer disc remained attached to the fish. This probably explains the loss of both tags by two fish on which nickel pins had been used. Table 3 summarizes the condition of nickel pins on tagged fish. o •o T3 Id J3 O O. O Controls Discussion and Conclusions All of the nickel pins in the aquarium control lot were corroded. In the bent pins the degree of failure ranged from pitting and surface corrosion to hollowing. All of the straight pins were hollowed, and broke when tested with pliers. The control pins in the harbor showed varied resistance to corrosion. Two bent pins bore minor surface corrosion at the bend, the other three were unjiffected. Two of the straight pins showed minor surface corrosion and one was unaffected. The remaining two were lost during the experi- ment . Stainless Steel Pins On Tagged Fish The stainless steel pins were almost completely free from corrosion. Three pins showed rust spots and one pin was partially worn through by abrasion from the outer disc. These results agree well with those of Forrester and Ketchen (1955) who used pins of Type 316 stainless steel in a field tagging study. Type 316 differs from the Type 304 used in this experiment mainly in having 15 times as much molybdenum (Anon. 1947). Controls None of the control stainless steel pins were affected by immersion in the aquarium or in the harbor. Table 3. --Summary of the average condition of the nickel used to tag fish Time on Fish Days Condition 1 - 21 22 - 42 43 - 61 62 - 64 Minor corrosion Moderate surface corrosion Moderate to extensive corrosion Extensive corrosion; hollowed pins ili Most of the structural damage to the pins occurred where the pin contacted fish tissue. Body fluids of the fish may have been primarily responsible for the corro- sion of the nickel pins on fish. Addi- tional factors (Calhoun, Fry and Hughes 1951) which may have entered into the pro- cess which caused the pin damage are the galvanic effect produced by dissimilar metcils (i.e., stainless steel, nickel and the iron pipes and drain screens) immersed in the aquarium tanks and/or the concentra- tion-cell effect produced by a metal immersed in a mixture of electrolytes (i.e., fish excretory products and sea water). Electrolysis from either cause, coupled with actual chemical corrosion, would accelerate destruction of the pins. This could explain why the nickel control pins in the tanks were more corroded than the nickel control pins in the harbor which corroded slightly or not at all. The airtif iciality of the aquarium tanks as a fish habitat should be con- sidered before any strict conclusions are drawn concerning the usefulness of the pins which were tested in this study. However, since the nickel pins did corrode in the aquarium and to some extent in the harbor, it is reasonable to assume they would corrode in the open sea over a period of months instead of weeks. This conclusion is supported by the number of nickel pins which have corroded in the field tagging of haddock. Similarly, since the stainless steel pins did not corrode in the aquarium or in the harbor they probably would not corrode in field use. Based on the results of these studies we have decided to stop using nickel pins for tagging haddock. Since the Type 304 stainless steel pins we tested are resistant to corrosion by the metabolic pro- ducts of the haddock and also resistant to corrosion by raw sea water, we are using them exclusively in field tagging of several marine species. The pins were used in an extensive haddock tagging program conducted in 1956 and 1957. When sufficient returns are available, the relative corrosion resistjuice of the stainless steel and the nickel pins in actual field use will be compared. pins 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. APPENDIX Table A. --Condition of pins and opercula following tagging Nickel Pins Tag Day! No. Fish 60 1 41 8 21 10 51 21 15 42 33 42 37 53 98 57 22 57 1/ Pin Condition Operculum Condition Remarks 82 43 59 31 57 57 58 58 No corrosion Minor surface corrosion at operculum. Minor surface corrosion at operculum. Minor surface corrosion at operculum. Moderate surface corrosion at operculum. Moderate surface corrosion at operculum. Hollowed at operculum. Lost in tank. Extensive surface corro- sion at operculum. Abraded by inner disc. Moderate surface corro- sion at operculum. Abraded by outer disc. Extensive surface corro- sion at operculum. Moderate surface corro- sion at operculum. Moderate surface corro- sion at operculum. Pin pitted near head on shank. Good Good Good Good Ulcerated, both sides. Good Minor sore, both sides. Minor ulceration externally. Inner disc grown over. Moderate ulceration externally. Inner disc grown over. Severe ulceration externally. Inner disc grown over. Severe ulceration externally. Moderate ulceration internally. Moderate ulceration both sides. 76 59 Minor surface corrosion at operculum. Good 27 61 Moderate surface corro- Minor ulcers sion at operculum. Pitted both sides. under head. 29 63 Hollowed at operculum. Decomposed 80 63 Hollowed and broken. Head and inner disc missing in tank. Good 32 63 Lost in tank. Black granular tissue around pin. Black granular tissue around pin. Black granular tissue around pin. Black granular tissue around pin. Tight tag, dropped off operculum. Black granular tissue around pin. Loose tag. Loose tag. Dead in tank several days. Part of tag broken off. — / Days on fish refers to elapsed time between the day the fish was tagged and the day it died. APPENDIX Table B. --Condition of pins and opercula following tagging Stainless Steel Pins Tag Days on Fish i/ Pin Condition No. 19 4 No corrosion 71 7 No corrosion 94 7 No corrosion 57 8 No corrosion 77 8 No corrosion 70 14 No corrosion 24 22 No corrosion 56 42 Rust spot at twist, 45 53 No corrosion. 89 57 No corrosion 84 58 No corrosion Operculum Condition Remarks 65 42 91 64 39 03 46 58 58 58 61 61 63 64 Abraded by outer disc. Rust spot at twist. No corrosion No corrosion No corrosion No corrosion except black spot near pin head. Abraded by outer disc. Rust spot at twist. No corrosion Good Good Good Good Good Moderate ulceration both sides of operculum. Ulcerated, both sides. Ulcerated, both sides, yicerated, both sides. Inner Euid outer discs grown over. Minor ulceration externally. Inner disc grown over. Moderate ulceration exter- nally. Inner disc partially grown over. Severe ulceration exter- nally. Inner disc grown over. Good Severe ulceration exter- nally. Inner disc grown over. Severe ulceration, both sides. Severe ulceration, both sides. Severe ulceration, both sides. Minor ulceration externally. Tight tag. Black granular tissue around pin. Tight tag. Tight tag. Black granular tissue around pin. Loose tag. —I Days on fish refers to elapsed time between the day the fish was tagged and the day it died. INT.-DOP. SEC, WASH., D.C. u 8 U 3 0 MBL WHOI Library - Serials 5 WHSE 01262