Rogers et at: Effectiveness of bycatch reduction devices in Louisiana inshore waters 
553 
also been used. The minimum legal stretch mesh size 
at the time of the present study was 3.2 cm; how- 
ever, shrimpers often use larger mesh to reduce the 
catch of small shrimp and nontarge ted (by catch) or- 
ganisms. 
Some methods that shrimpers have used to reduce 
bycatch have included relocating to areas of lower 
fish concentrations, cutting openings in nets, reduc- 
ing tow speeds before haulback, and modifying nets 
in various ways. Heightened pressure by environ- 
mental organizations and pending legislation to re- 
duce bycatch has furthered the development of 
shrimp trawls equipped with bycatch reduction de- 
vices (BRD’s) to reduce the catch of nontargeted or- 
ganisms. Previous research on BRD designs tested 
in the United States has been summarized by Watson 
and Taylor. 3 
Some of the BRD designs used successfully in other 
shrimp fisheries have proven ineffective in Gulf of 
Mexico waters. For example, a horizontal separator 
panel yielded a 75% reduction in bycatch but lost 
30% of the shrimp (Seidel, 1975). Seidel (1975) tested 
six modifications of the Pacific Northwest shrimp 
3 Watson, J. W., and C. W. Taylor. 1990. Research on selective 
shrimp trawl designs for penaeid shrimp in the United States: 
a review of selective shrimp trawl research in the United States 
since 1973. Proceedings ASMFC Fisheries Conservation En- 
gineering Workshop, Narragansett, RI, April 1990, 21 p. 
separator trawl, which has a vertical separator panel 
and several chutes for fish escapement. Shrimp losses 
ranged from 9.1% to 63.5%, and fish reduction ranged 
from 37% to 83.5%; however, the modification with 
the best fish reduction had a shrimp loss of 63.5%. 
The lowest attainable shrimp loss (6%) from a trawl 
with vertical separator panels of varying mesh had 
a 45% bycatch reduction (Watson and McVea, 1977). 
The Gulf has a high diversity of bycatch species, 
many of which are similar in size to shrimp; shrimp, 
however, may represent as little as 10% of the total 
catch (Seidel, 1975). Prior to this study, most evalu- 
ations of BRD’s in the Gulf had been conducted in 
offshore waters. Inshore organisms are often smaller 
than those caught offshore, inshore trawls and ves- 
sels are typically smaller, and trawling conditions, 
such as water depth and turbidity, may differ. Be- 
cause of these differences, the present study was 
designed to determine the performance of four BRD’s 
in inshore waters of Louisiana. 
Materials and methods 
Bycatch reduction devices 
To gather regional expertise on trawling and BRD 
design, an advisory committee of shrimpers, net 
makers, and fishery-related agency personnel was 
