Brown et al.: Simple gear modifications for bycatch reduction in a shrimp trawl fishery 
373 
of TEDs and BRDs has been required by federal and state 
law since the early 1990s in all commercial shrimp trawl 
fisheries in the southeastern United States. 
In the United States, penaeid shrimp account for approxi¬ 
mately 11% of the $5.3 billion total ex-vessel value reported 
for domestic fisheries in 2016 (NMFS 2 ). Approximately 70% 
of domestic shrimp harvest occurs in the Gulf of Mexico, and 
North Carolina is typically the top producer among states on 
the East Coast. From 2013 through 2017, commercial fish¬ 
ermen in North Carolina landed an average of 4130 Mg of 
shrimp with an ex-vessel value of $20.0 million (NCDMF 3 ). 
The fishery in North Carolina targets brown ( Farfan tepe- 
naeus aztecus), pink (F. duorarum), and white ( Litopenaeus 
setiferus) shrimp. All 3 species are considered annual crops, 
implying that natural mortality rather than fishing pres¬ 
sure has the greatest effect on population size (NCDMF, 
2015). This fishery is unique among those in East Coast 
states and much of the Gulf of Mexico in that approximately 
75% of the shrimp harvest comes from inshore, estuarine 
waters (NCDMF, 2015). Approximately 92% of the har¬ 
vest is captured with bottom otter trawls because other 
gears, such as channel nets, skimmer trawls, and shrimp 
pots, are not generally suitable for operating in the deeper, 
often muddy estuarine systems (e.g., Pamlico Sound, North 
Carolina) (NCDMF, 2015). 
The shrimp fishery in North Carolina is controversial 
because of the amount of finfish bycatch in the fishery and 
the resulting discard of commercially and recreationally valu¬ 
able fish species, such as the southern flounder ( Paralichthys 
lethostigma ), summer flounder ( P dentatus), Gulf flounder 
(P. albigutta ), weakfish (Cynoscion regalis ), spot (Leiostomus 
xanthurus), and Atlantic croaker (Micropogonias undulatus) 
(Murray et al., 1992; SAFMC, 1996; NCDMF, 2015). 
Management and research efforts to curb bycatch 
in North Carolina are longstanding and significant. In 1992, 
North Carolina became the first state on the East Coast 
to require BRDs in shrimp trawls (NCDMF, 2015). State 
fisheries biologists have tested existing BRDs (Holland 4 ; 
McKenna and Monaghan 5 ; Brown 6 * ), experimented with 
2 NMFS (National Marine Fisheries Service). 2017. Fisheries of 
the United States, 2016. NOAA Curr. Fish. Stat. 2016, 147 p. 
[Available from website.] 
3 NCDMF (North Carolina Division of Marine Fisheries). 2019. 
2019 license statistics annual report, 424 p. Div. Mar. Fish., 
North Carolina Dep. Environ. Qual., Morehead City, NC. [Avail¬ 
able from website.] 
4 Holland, B. F., Jr. 1989. Evaluation of certified trawl efficiency 
devices (TEDs) in North Carolina’s nearshore ocean. North Car¬ 
olina Dep. Nat. Resour. Comm. Dev., Div. Mar. Fish., Compl. Rep. 
Proj. 2-439-R, 38 p. [Available from website.] 
5 McKenna, S. A, and J. P. Monaghan Jr. 1993. Gear development to 
reduce bycatch in the North Carolina trawl fisheries. North Carolina 
Dep. Environ. Health Nat. Res., Div. Mar. Fish., Compl. Rep. Coop. 
Agreement No. NA90AA-H-SKO52,59 p. [Available from website.] 
6 Brown, K. 2010. Interstate fisheries management program 
implementation for North Carolina. Study 2: documentation and 
reduction of bycatch in North Carolina fisheries. Job 1: compare 
catch rates of shrimp and bycatch of other species in standard 
(control) and modified (experimental) otter trawls in the Neuse 
River and Pamlico Sound, North Carolina. North Carolina Dep. 
Environ. Nat. Res., Div. Mar. Fish., Compl. Rep. NOAA Award 
No. NA08NMF474076, 23 p. [Available from website.] 
modified trawls (He et al.'), and conducted statewide 
bycatch characterization studies (Brown 8 ). Academic sci¬ 
entists have partnered with industry to reduce bycatch 
on multiple occasions (Murray et al., 1992; Rulifson et al., 
1992). Likewise, members of the commercial shrimp indus¬ 
try have participated in numerous collaborative research 
projects addressing bycatch issues, including at least 21 
short-term projects funded by the North Carolina Sea 
Grant from 1995 through 2013 (information about these 
projects is available from website). 
In 2014, the North Carolina shrimp fishery management 
plan was amended by the North Carolina Marine Fisher¬ 
ies Commission (NCMFC) to focus exclusively on reducing 
finfish bycatch in the bottom otter trawl fishery (NCDMF, 
2015). The overall objective of the research reported here 
was to address this management goal by evaluating gear 
modifications capable of achieving bycatch reductions 
relative to control trawl gears while minimizing shrimp 
loss. To achieve this goal, the project team set forth the 
following objectives: 1) convene a workgroup to devise and 
prioritize experimental gears to be tested, 2) conduct com¬ 
parable paired tows aboard commercial fishing vessels, and 
3) compare results to catch data observed in control nets. 
The desired outcome was to develop technical solutions 
within 3 years that met a bycatch reduction target of 40% 
(above that achieved with a control gear), as recommended 
by the NCMFC, while maintaining shrimp catches. 
Materials and methods 
Workgroup 
Prior to gear selection and testing, we convened a 12-member 
workgroup consisting of commercial fishermen, net makers, 
and industry representatives from North Carolina. Multiple 
international gear experts attended the first meeting and 
provided advice relevant to the needs of the fishery in North 
Carolina (Brown et al. 9 ). The purpose of this workgroup 
was to provide feedback throughout the project, from gear 
' He, R, C. Rillahan, K. Brown, T. Lewis. 2016. Design and test of a 
topless shrimp trawl to reduce finfish bycatch in Pamlico Sound, 
North Carolina, 55 p. Final report submitted to NOAA Saltonstall- 
Kennedy Grant Program for grant SMAST-CE-REP-2016-057. 
[Available from School Mar. Sci. Technol., Univ. Mass. Dartmouth, 
285 Old Westport Rd., New Bedford, MA 02747-2300.] 
h Brown, K. 2015. Characterization of the commercial shrimp 
otter trawl fishery in the estuarine and ocean (0-3 miles) 
waters of North Carolina, 165 p. Final report to the National 
Fish and Wildlife Foundation and the National Oceanic and 
Atmospheric Administration National Marine Fisheries Ser¬ 
vice for the study period August 2012-August 2015. Div. Mar. 
Fish., North Carolina Dep. Environ. Qual., Morehead City, NC. 
[Available from website.] 
9 Brown, K., B. Price, L. Lee, S. Baker, and S. Mirabilio. 2017. Tech¬ 
nical solutions to reduce bycatch in the North Carolina shrimp 
trawl fishery, 50 p. Final Report to the North Carolina Marine 
Fisheries Commission and the National Oceanic and Atmo¬ 
spheric Administration Bycatch Reduction Engineering Program 
for the study period June-July 2015 and July-September 2016. 
Div. Mar. Fish., North Carolina Dep. Environ. Qual., Morehead 
City, NC. [Available from website.] 
