KKSHEKY BULLETIN: VOL. 86, NO. 1 



the family level of significance would not exceed 

 0.15. All other tests were made with a signifi- 

 cance level of u = 0.05. Mean catch rates and con- 

 fidence intervals computed from transformed 

 data were back-transformed for tabular and 

 graphic presentation (Elliott 1979). 



RESULTS 



Fishing trotlines on the bottom reduces bycatch 

 without affecting catches of black drum, the 

 target species. A significant difference could not 

 be detected between black drum catch rates on 

 top and bottom trotlines regardless of bait, sea- 

 son, or bay (Tables 2, 3). Catch rates for hardhead 

 catfish, red drum, spotted seatrout and total 

 fishes were significantly lower on bottom trot- 

 lines than on top trotlines (Tables 2, 3). Differ- 

 ences in catch rates between top and bottom trot- 

 lines for hardhead catfish, red drum, and total 

 fishes did not vary significantly among seasons 

 and baits but did vary between bays based on the 

 first-order interactions (Tables 4, 5). A significant 

 second-order interaction of position x bay x bait 

 for spotted seatrout revealed that differences be- 

 tween top and bottom trotlines were affected by 

 both bait and bay but not by season (Fig. 4). 



No significant difference was found in red drum 

 catch rates among baits nor in spotted seatrout 

 catch rates among seasons (Tables 2, 3). All other 

 main effects were significant for catch rates of all 

 species and total fishes. Of the possible first-order 

 interactions involving bait, season, and bay, only 

 season x bait for hardhead catfish, red drum, and 

 total fishes, bait x bay for black drum and total 

 fishes, and season x bay for black drum, hard- 

 head catfish, and total fishes were significant (Ta- 

 bles 4, 5). The second-order interaction of 

 bait X bay x season for total fishes was signifi- 

 cant (Fig. 5). 



No significant differences were found in mean 

 lengths of black drum, hardhead catfish, red 

 drum, and spotted seatrout between top and bot- 

 tom trotlines (Tables 6-8). Significant differences 

 in mean length of hardhead catfish were detected 

 for main effects of bait and season (Table 7). 



DISCUSSION 



Management objectives could be better met by 

 requiring placement of trotline hooks on bottom 

 than by allowing hooks to be fished from the sur- 

 face. Red drum and spotted seatrout mortality 

 would be reduced without significantly affecting 



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