730 



Evaluation of small T-anchor and dart tags 

 for use in marking hatchery-reared juvenile 

 red drum, Sciaenops ocellatus 



Brent L. Winner 

 Robert H. McMichael Jr. 



Laurel L. Brant 



Florida Marine Research Institute 



Florida Department of Environmental Protection 



100 Eighth Avenue SB, St, Petersburg, Florida 33701-5095 



Email address (For B L Winner) W/innerBgepic7dep State fl us 



Red drum, Sciaenops ocellatus, is 

 an estuary-dependent marine spe- 

 cies found in coastal and nearshore 

 waters in the western Atlantic 

 Ocean from Maine to Florida and 

 in the Gulf of Mexico from Florida 

 to Vera Cruz, Mexico (Yokel, 1966, 

 1980). Red drum are highly sought 

 after as food and gameflsh. Annual 

 commercial landings in Florida av- 

 eraged nearly 1.0 million pounds 

 from the early 1960s until 1986, 

 when the sale of red drum was pro- 

 hibited. Recreational fishing effort 

 directed toward red drum in Florida 

 has more than doubled since 1989 

 on both the Atlantic and Gulf coasts 

 (Murphy'). Increased fishing pres- 

 sure on red drum stocks has led to 

 the implementation of various man- 

 agement strategies, such as closing 

 the commercial fishery and reducing 

 the recreational catch by means of 

 bag limits, size limits, and closed sea- 

 sons. In the 1970s, methods were 

 developed for culturing red drum in 

 controlled hatchery environments, 

 providing a pathway for the use of 

 stock enhancement for managing the 

 fishery (Arnold et al., 1977; Roberts 

 et al., 1978a, 1978b). Red drum stock 

 enhancement has been conducted ex- 

 tensively in Texas and, to a lesser de- 

 gree, in Florida and South Carolina 

 (Matlock et al., 1986; Willis et al., 

 1995; Smith etal.^). 



Monitoring stocked fish popula- 

 tions in the wild is critical in deter- 



mining the impact of stocked fish 

 on the fishery and the natural 

 population. Red drum are stocked 

 at various sizes: (phase-1 (25-50 

 mm SL); phase-2 (50-100 mm SL); 

 and phase-3 ( 100-200 mm)). Stock- 

 ing larger size red drum (phase-2 

 or -3), facilitates the use of tagging 

 as a method of tracking these fish 

 in the wild. Tagged fish can provide 

 valuable data on stock identity, 

 fishing pressure, movements, abun- 

 dance, age and growth, mortality, 

 and stocking-program success 

 (Ricker, 1956; Hilborn et al., 1990; 

 McFarlane et al., 1990). However, 

 the usefulness of these data de- 

 pends on knowledge of tag-reten- 

 tion rates and of the effects of tag- 

 ging on fish growth and survival. 



A variety of tag types have been 

 tested on red drum of various sizes. 

 Several studies have evaluated the 

 use of coded wire tags in juvenile 

 red drum (phase-2, 50-100 mm SL, 

 Bumguardner et al., 1990, 1992; 

 Szedlmayer and Howe, 1995). Be- 

 cause coded wire tags are not ex- 

 ternally visible, recreational and 

 commercial fishermen are not 

 likely to see them and therefore are 

 not likely to submit capture data 

 to authorities; externally visible 

 tags are better suited for obtaining 

 capture information from recre- 

 ational and commercial fishermen. 



Externally visible tags are typi- 

 cally restricted to use in red drum 



larger than 100 mm (phase-3 fish). 

 Retention of externally visible tags 

 in phase-3 red drum ( 100-200 mm 

 SL) has not been rigorously tested, 

 and little is known of the effects of 

 these tags on survival or growth in 

 this size of red drum. Some studies 

 have tested the effects of various 

 external tags on large red drum 

 (>300mmSL;Elam, 1971; Weaver, 

 1976; Hein and Shepard, 1980a; 

 Gutherz et al., 1990 ). Matlock et al. 

 (1984) reported using Monel jaw 

 tags and Willis et al. (1995) re- 

 ported using internal-anchor tags 

 in fmgerling red drum (100-200 

 mm SL), but neither report ad- 

 dressed tag-retention rates or ef- 

 fects of tags on growth or survival. 

 The Florida Department of En- 

 vironmental Protection's Stock En- 

 hancement and Research Facility 

 (SERF) has the capability of rear- 

 ing phase-1, -2, and -3 red drum for 

 release. Data from this study were 

 used to evaluate the efficacy of two 

 types of external tags in hatchery- 

 reared phase-3 juvenile red drum, 

 and to provide tag-retention and 

 survival estimates, which are nec- 

 essary for correctly interpreting 

 capture information. 



Materials and methods 



Retention of T-anchor and dart tags 

 in hatchery-reared red drum ( 102- 

 173 mm SL) was evaluated over a 

 423-day period. Mortality associ- 



' Murphy, M. D. 1994. A stock assess- 

 ment for red drum, Sciaenops ocellatus, 

 in Florida. Florida Marine Research 

 Institute. Report to the Fla. Mar. Fish. 

 Comm., Tallahassee, FL, 28 p. 



•^ Smith T. I. J., M. R. Denson, D. B. White, 

 andW. E.Jenkins. 1993. Evaluation of 

 a preliminary red drum stock enhance- 

 ment program in South Carolina. SC 

 Wildl. Mar Res. Dep., Mar Resour Res. 

 Inst. Annu. Performance Rep. Charleston. 

 SC, 21 p. 



Manuscript accepted 16 September 1998. 

 Fish. Bull. 97:730-73.5 (1999). 



