374 
Fishery Bulletin 117(4) 
Table 1 
Characteristics of the control and the 9 experimental shrimp otter trawls (gears) that were tested in Pamlico Sound and nearshore 
waters off North Carolina during 2015-2017. The state and federal fisheye bycatch reduction devices (BRDs), as constructed 
for this study, created openings of 131 cm 2 and 258 cm 2 , respectively. All experimental gears included a typical net body, a trawl 
efficiency device (TED), one or more BRDs, and a codend. Some of the gears had TEDs with reduced bar spacing. The cost for an 
industry manufacturer to construct a single control gear for this study was $3000. N/A=not applicable. 
Configuration 
Year 
Gear description 
TED bar 
spacing 
(cm) 
BRD 
Codend 
mesh size 
(cm) 
Costs to 
retrofit one 
control net 
All 
Control 
10.16 
1 state fisheye 
3.81 
N/A 
2015 
Composite panel 
10.16 
Composite panel, spooker cone, 
1 state fisheye 
3.81 
$400 
Reduced-bar TED 
7.62 
1 state fisheye 
3.81 
$700 
Reduced-bar TED + square mesh panel + 
4.76-cm codend 
7.62 
1 state fisheye, square mesh 
panel 
4.76 
$1250 
Ricky BRD 
10.16 
Ricky 
3.81 
$110 
Double federal fisheyes + 4.76-cm codend 
10.16 
2 federal fisheyes 
4.76 
$600 
2016 
Virgil Potter BRD 
10.16 
1 state fisheye, Virgil Potter 
3.81 
$275 
Double federal fisheyes + 4.45-cm codend 
10.16 
2 federal fisheyes 
4.45 
$600 
Reduced-bar TED + double federal fisheyes + 
4.45-cm codend 
7.62 
2 federal fisheyes 
4.45 
$1250 
Virgil Potter BRD + 4.45-cm codend 
10.16 
1 state fisheye, Virgil Potter 
4.45 
$800 
2017 
Reduced-bar TED 
7.62 
1 state fisheye 
3.81 
$700 
Reduced-bar TED + 4.13-cm codend 
7.62 
1 state fisheye 
4.13 
$1225 
Reduced-bar TED + double state fisheyes + 
4.13-cm codend (summer) 
7.62 
2 state fisheyes 
4.13 
$1250 
Reduced-bar TED + double state fisheyes + 
4.13-cm codend (autumn) 
7.62 
2 state fisheyes 
4.13 
$1250 
Reduced-bar TED + double federal fisheyes + 
4.13-cm codend 
7.62 
2 federal fisheyes 
4.13 
$1250 
selection and testing to overall evaluation of the gear results 
and of an acceptable amount of shrimp loss. Meetings were 
held at the beginning of the project and following annual 
testing trials. 
Selection of BRDs and gear combinations for testing in 
this study was guided by multiple factors, including existing 
state regulations, advice from international gear experts, 
and feedback from workgroup members and industry rep¬ 
resentatives. Additionally, a state management regulation 
issued by proclamation in 2015 after the start of this study 
mandated that shrimp fishermen install an additional 
BRD, for a total of 2 devices, allowing various BRD com¬ 
binations (NCDMF 10 ). The workgroup selected 14 gears by 
consensus for testing in 2015, 2016, and 2017 (Table 1). 
Gear testing procedures 
A formal procedure for comparing tows (experimental ver¬ 
sus control) was developed and closely followed the 
10 NCDMF (North Carolina Division of Marine Fisheries). 2015. 
Re: Shrimp trawl BRD requirements. Proclamation SH-2-2015. 
Div. Mar. Fish., North Carolina Dep. Environ. Nat. Resour., 
Morehead City, NC. [Available from website.] 
procedure outlined in the NOAA BRD testing manual 
(NMFS 11 ). A target of 60 successful paired tows was set for 
sampling in 2015, as mandated by the NCMFC, and a min¬ 
imum target of 30 successful paired tows was set for the 
fishing seasons in 2016 and 2017 (NMFS 11 ). A successful 
tow was defined as the control and experimental trawl 
fishing without indication of occurrence of problematic 
events (e.g., hangs or gear malfunction) that could have 
influenced fishing efficiency (i.e., catch). All paired tows 
were performed on 9 commercial shrimp vessels equipped 
with bottom otter trawls (3 vessels in 2015, 2 vessels in 
2016, and 4 vessels in 2017). During the trials in 2015 and 
2016, all vessels were greater than 12 m long and were 
rigged with 4 trawl nets (double rigged) (Figs. 1 and 2), and 
the vessels from which trials were conducted in 2017 
ranged from 10.5 m to 18 m in length and were rigged with 
2 trawl nets (twin rigged). The control and experimental 
nets were tested in the outside positions on double-rigged 
vessels, and trials conducted on double-rigged vessels 
11 NMFS (National Marine Fisheries Service). 2016. Bycatch 
reduction device testing manual, 8 p. Southeast Reg. Off., Natl. 
Mar. Fish. Serv., NOAA, St. Petersburg, FL. [Available from 
website.] 
