NOTE Winner et a\ : Evaluation of T-anchor and dart tags for use in marking Saaenops ocel/atus 



733 



100 



c 



O 



0. 



60 - 



' Dart 1 

 Dan 2 



20 



40 



60 



Days 



100 



120 



Figure 3 



Survival of red drum in each treatment group during the first 112 days of the study. 



versely affect fish growth. It is important that a tag- 

 ging method not affect growth ( Ricker, 1956; Wydoski 

 and Emery, 1983), especially when tagging is being 

 used to verify aging methods (e.g. oxytetracycline 

 injection) or to estimate survival rates in the wild 

 (Green et al., 1985; McFarlane et al., 1990). Growth- 

 rate estimates of red drum in our study (0.41-0.50 

 mm/day) were lower than those for this size of red 

 drum reported in other studies (Colura and Hysmith, 

 1975; Hein and Shepard, 1980b), possibly because of 

 the high stocking densities in the net pens. 



In summary, dart and T-anchor tags are well suited 

 for marking juvenile phase-3 red drum ( 102-173 mm 



SL) and are usually retained until the fish are large 

 enough to enter the fishery (Florida minimum size 

 limit for red drum is 368 mm SL). Both tag types 

 were easy to apply and did not affect red drum growth 

 or survival. Although tag retention, survival, and 

 growth rates did not differ between tag types, our 

 results did reveal some potential problems associ- 

 ated with the long-term use of T-anchor tags. The 

 wound around the insertion point of the T-anchor tags 

 did not heal during the 423 days of our experiment, 

 and late in the study, some tags showed signs of ex- 

 pulsion (anchor protrusion through abdominal wall). 

 Both tag types could be used to track releases of 



