Long-term coded wire tag retention 

 in juvenile Sciaenops ocellatus 



Britt W. Bumguardner 

 Robert L. Colura 



Texas Parks and Wildlife Department, Perry R, Bass Marine Fisheries Research Station 

 HC 2, Box 385, Palaclos, Texas 77465 



Gary C. Matlock 



Texas Parks and Wildlife Department, Fisheries and Wildlife Division 

 4200 Smith School Road, Austin, Texas 78744 



Red drum Sciaenops ocellatus, a 

 popular sport fish in the Gulf of 

 Mexico and associated estuarine 

 systems, have been subjected to in- 

 creasing fishing pressure in recent 

 years which has led to declining 

 population size in Texas (Matlock 

 1982) and poor annual survival in 

 Texas bays (Green et al. 1985). 

 Commercial harvest of both inshore 

 stocks of red drum in Texas prior 

 to 1981 (Matlock 1982) and offshore 

 stocks in the Gulf of Mexico prior to 

 1987 (Goodyear 1987) contributed 

 to the apparent population decline 

 in red drum. Documented commer- 

 cial landings in the Gulf of Mexico 

 were less than 50% of estimated 

 recreational harvest prior to 1984. 

 However, documented commercial 

 landings increased to more than 

 double the estimated recreational 

 harvest from 1984 to 1986, primar- 

 ily due to expansion of an oceanic 

 purse seine fishery which began in 

 1978 (Goodyear 1987). 



In Texas, reported commercial 

 landings of red drum were more 

 than double estimated recreational 

 landings for 1976-77, then declined 

 to slightly more than recreational 

 landings for 1978-80. Estimated 

 recreational landings were relative- 

 ly stable, with a general downward 

 trend, during 1976-80 (Matlock 

 1982). The sale of red drum har- 

 vested from Texas public waters 

 was prohibited by legislative action 

 as of 1 September 1981 (Maddux et 



al. 1989), while the purse seine fish- 

 ery for offshore stocks of adult red 

 drum was closed by the Gulf of Mex- 

 ico Fisheries Management Council 

 in 1986. Increasing sportfishing 

 pressure and catastrophic freezes, 

 which caused extensive fish kills in 

 bays along the northern Gtilf of 

 Mexico (Maddux et al. 1989), have 

 also contributed to imposition of in- 

 creasingly restrictive sport bag and 

 size limits for red drum in Texas. 

 Development of controlled spawn- 

 ing and pond culture techniques for 

 red drum has allowed large-scale 

 production and stocking of red 

 drum fingerlings to enhance declin- 

 ing populations (Colura et al. 1976, 

 Arnold et al. 1977, McCarty et al. 

 1986). Over 68 million red drum 

 fingerlings have been stocked for 

 population enhancement in Texas 

 coastal waters since 1975, with 

 the majority of fingerlings stocked 

 since 1983 (Dailey 1990). Develop- 

 ment of a reliable method for iden- 

 tifying stocked fish would allow 

 evaluation of this stocking program. 

 The fish, which are typically <50 

 mm total length (TL) when stocked 

 (Dailey 1990), are frequently re- 

 leased in spring and summer when 

 no small red drum (<100mmTL) 

 occur naturally in bays (McEachron 

 and Green 1986), as red drum 

 spawn in the fall (Comyns et al. 

 1991). Survival of fish stocked in 

 spring and summer can be moni- 

 tored by analysis of length-frequen- 



cies for about 9 months, at which 

 time variation in growth masks the 

 initial length differences. Fish 

 stocked in fall cannot be monitored 

 by length-frequency methods due to 

 onset of the spawning season and 

 resultant confusion of stocked and 

 wild fish of similar size (Dailey and 

 McEachron 1986, Matlock et al. 

 1986). 



For stocking to be considered suc- 

 cessful, hatchery fish must survive 

 long enough to be recruited to the 

 fishery and then to offshore schools 

 of mature red drum. When evalua- 

 tion of stocking success is based on 

 recapttire of tagged fish which must 

 grow large enough to enter the 

 fishery, determination of long-term 

 tag retention and detection rates is 

 necessary for accurate evaluation 

 of fingerling stocking success. Ap- 

 preciable tag loss or nondetection 

 would result in underestimation of 

 the proportion of hatchery fish in 

 the population (Heimbach et al. 

 1990). 



Tagging of hatchery fish has had 

 little success (Matlock et al. 1984 

 and 1986, Gibbard and Colura 1980, 

 Bumguardner et al. 1990). Only 10 

 of 5942 hatchery-reared red drum 

 {x 452mmTL) tagged with monel 

 jaw tags on the opercula were re- 

 captured within 8 months of release 

 (Matlock et al. 1984). Three fish 

 from over 38,000 fingerlings (40- 

 120mmTL) tagged in the snout 

 with coded wire microtags and 

 released in St. Charles Bay, Texas, 

 were recaptured (Matlock et al. 

 1986). The low recapture rate of 

 microtagged fish was probably due 

 to tag loss. Gibbard and Colura 

 (1980) reported 27% retention of 

 coded wire tags placed in the nose 

 of red drum fingerlings (50 mm 

 mean TL) after 1 year. Bumguard- 

 ner et al. (1990) conducted a short- 

 term study (114 days) of red drum 

 fingerlings (x 52mmTL) tagged in 

 the adductor mandibularis (cheek 



Manuscript accepted 9 March 1992. 

 Fishery Bulletin, U.S. 90:390-394 (1992). 



390 



