Denson et a\ Tag-reporting levels for Sciaenops ocellatus in Sorith Carolina and Georgia estuaries 



39 



and nineteen anglers in SC (79.0'7r of total anglers) 

 reported only one tagged fish during the study. In GA, 184 

 anglers reported capture of 226 tagged fish. Single reports 

 in GA represented 80.4''; (;( = 148i of the total catch of 

 tagged fish. The overall return level for all fish reported in 

 SC (22.7 [±1.8]%) was not significantly different from that 

 in GA (25.8 [±4.1]%) (P=0.8129. F=0.67) (Table 2). For the 

 cumulative data, no significant differences were detected 

 between "$100 reward" (27.8 [±3.3]%l and "reward" tags 

 (20.8 [±2.7]%) (P=0.0724, F=12.33l (Table 2). There were 

 also no statistical differences in the cumulative data 

 among the estuaries within states (P=0.0604. F=4.07) 

 (Table 2) and no detectable interaction between state and 

 reward or reward and estuary within states, from the high 

 variability in the cumulative data among estuaries and 

 sites (52.5% and 47.5% of total variation, respectively). 



Single returns 



To further restrict the potential for bias caused by inter- 

 action of different reward messages or caused by the 

 project biologist, capture reports were partitioned to 

 include instances where an angler returned only one 

 tag during the entire study. Overall, no significant differ- 

 ences (P=0.1215,F=6.76) were detected between the single 

 returns of "reward" (11.6 [±1.11% ) and "$100 reward" ( 15.0 

 [±2.5]%) treatments within SC. This was also the case 

 in GA (P=0.1215, F=6.760 where 15.1(±2.9)% of "reward" 

 tags were returned, as compared with 17.6 (±2.7)% for 

 "$100 reward" tags (Table 3). In addition, when data were 

 compared between states, no differences were detected 

 (P=0.6152, F=0.35). However, when single returns among 

 estuaries were compared, Wassaw Sound in GA (Fig. 1) 

 yielded significantly higher returns (P=0.0126, P=7.95) 

 than any of the other estuaries where fish were released 

 (Table 3 1. 



Survey data 



In SC, 52% of respondents indicated that they had previ- 

 ously caught tagged fish. Of those, several anglers admit- 

 ted that they had not routinely reported tags. Additionally, 

 others ( 16% ) indicated that they would not have reported 

 the tag if it had not been worth $100. In one extreme case 

 an angler who reported six "$100 reward" tags and an 

 equal number of "reward" tags at once, indicated that he 

 would not have turned in an individual "$100 reward" tag 

 because in his words "he did not need the money." 



In GA, 29% of anglers had caught a tagged fish prior to 

 the study; however only 7 ( 5% ) said that they would not 

 turn in tags worth less than $100. In light of this infor- 

 mation, the return data were partitioned to eliminate po- 

 tential bias that would result from encountering a "$100 

 reward" tag. This partitioned data set revealed that sig- 

 nificantly fewer (P=0.0310, F=30.81) unbiased "reward" 

 tags (14.3 [+2.1]%) were returned in SC than "$100 re- 

 ward" tags (25.5 [±2.3]%) (Table 4). This was also true in 

 GA, where 19.1(±4.3)% of "reward" tags were unbiased re- 

 turns, as compared with 30.1 (±6.4)*^"^ of "$100 reward" 

 tags (P=0.0310, F=30.81) (Table 4). 



Table 2 



Cumulative mean return level C/r) and standard error 

 for red drum tagged with one of two reward messages 

 ("reward" or "$100 reward"). No significant differences 

 were detected between reward message, estuary, or state. 



Release location 



Charleston Harbor 

 Calibogue Sound 

 South Carolina (mean) 

 St. Simons Sound 

 Wassaw Sound 

 Georgia (mean) 

 Overall mean 



Discussion 



Overall return levels for the tagged fish released in our 

 study were similar to levels of angler return for red 

 drum in each states fishery-dependent tagging programs 

 (Wenner^, Woodward''). Because of high variability within 

 estuaries, there were no significant differences between 

 returns of "reward" and "$100 reward" according to the 

 analysis of cumulative return data. The high variability 



Woodward. A. G. 1997. Personal commun. Georgia Depart- 

 ment of Natural Resources, 1 Conser\-ation Way, Brunswick, GA 

 31523. 



