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Fishery Bulletin 91(1). 1993 



ing and evaluating the impacts of TED use. The OMB 

 required a study on the efficiency of TEDs in exclud- 

 ing turtles, and the House Appropriations Committee 

 required a study of the full economic impact of TEDs. 



NMFS, in cooperation with the shrimp industry, ini- 

 tiated a TED Evaluation Program on 5 March 1988. 

 The objective of this program was to compare shrimp 

 catch rates of TED-equipped trawls with shrimp catch 

 rates of standard trawls in shrimp fishing grounds 

 from North Carolina to Texas. The assumption was 

 that shrimp CPUEs were equal both for vessels from 

 this study and from the commercial fleet fishing dur- 

 ing the same seasons and in the same Statistical Ar- 

 eas (Fig. 1). This paper reports on the results of the 

 program and on estimates of total shrimp loss to the 

 fishery through the use of TEDs. 



Materials and methods 



Recruitment of vessels 



Participation in the study by shrimpers was volun- 

 tary. Vessels and crews were neither leased nor char- 

 tered by NMFS. A payment of $100/d was sometimes 

 provided by the Gulf and South Atlantic Fisheries De- 

 velopment Foundation, generally when TEDs were not 

 required by law. This was an incentive for vessel own- 

 ers to allow NMFS personnel to collect data while on 

 board their vessels. 



Vessels were recruited with the assistance of NMFS 

 port agents, NOAA Sea Grant Marine Advisory agents, 

 regional shrimp associations, and industry contacts. 

 All participating vessels received appropriate federal 

 authorization to use TEDs in only half the trawls when 

 a NMFS observer was on board. Twenty-six quad-rigged 

 vessels (two trawls towed/side) and one twin-rigged 

 vessel (one trawl towed/side) were used in the study. 



Areas 



Beginning in March 1988, observers were placed on 

 shrimp vessels in each of the four major Gulf of Mexico 

 offshore fishing areas (Louisiana, Texas, south Florida, 

 and Alabama-Mississippi) and in the Atlantic off 

 Florida, Georgia, and North Carolina. Higher levels of 

 observer effort were allocated for areas which histori- 

 cally had higher shrimp production. Of 600 planned 

 observer days, 240 were scheduled for Louisiana, 200 

 for Texas, 50 each for east and west Florida, and 60 

 for Mississippi-Alabama. One-hundred observer days 

 were also scheduled for Georgia and North Carolina 

 waters. Observer days were targeted for peak regional 

 shrimping seasons in each area, although this sched- 

 ule was not always implemented due to constraints of 

 voluntary participation by the shrimp industry. 



The U.S. coasts of the Gulf of Mexico and Atlantic 

 Ocean are divided into Statistical Areas (Fig. 1) by 

 NMFS for analytical purposes. Areal groupings for 

 analyses in this study were Statistical Areas 1-8 (West 

 Florida), 9-12 (Florida Pan- 

 handle, Alabama, and Missis- 

 sippi), 13-17 (Louisiana), 18-21 

 (Texas), 28 (Cape Canaveral), 30- 

 31 (East Florida and Georgia), 

 and 34-35 (North Carolina). 



The study depended on 

 shrimpers volunteering to allow 

 NMFS personnel to collect data 

 onboard their vessels. Due to lim- 

 ited response by shrimpers, data 

 came from virtually any vessel 

 whose owner or captain would al- 

 low NMFS aboard. Since one of 

 the principal objectives of this 

 study was to evaluate the effect 

 of the use of TEDs on commer- 

 cial shrimping, the shrimpers de- 

 cided where and when to fish and 

 which certified TED to use. Our 

 only stipulations were that the 

 shrimper had to use federally ap- 

 proved TEDs, allow gear special- 

 ists to properly adjust the TEDs, 

 and keep catches from all nets of 



