IIFET 2000 Proceedings
Bycatch Effects on Quality of
Ocean Shrimp, Pandalus jordani
Vicki Hoover Krutzikowsky, Oregon State University, Newport, Oregon
Robert W. Hannah, Oregon Department of Fish and Wildlife, Newport, Oregon
Gilbert Sylvia, Oregon State University, Newport, Oregon
Michael Morrissey, Oregon State University, Astoria Oregon
IIFET 2000 Proceedings
Introduction and Methods
• Hypothesized that bycatch may affect the quality of the shrimp by
causing breakage.
• A double-rigged commercial shrimp vessel was chartered for test
fishing.
– One net employed a Nordmore grate BRD and the other served as
a control.
– Bycatch was measured from each net.
– The shrimp catch was kept separate by side of gear and day of
fishing.
• Shrimp samples were collected at seven stages from the deck to
finished product and evaluated for percent breakage by weight.
• Other factors such as ct/lb, molt condition and microbial counts
measured.
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IIFET 2000 Proceedings
% Pieces from belt sample
%
P
i
e
c
e
s
% Pieces before cooking
18
9
8
%
7
6
5
16
14
P 12
i 10
e
8
c
6
e
s
4
2
4
3
2
1
0
0
Excluder
No excluder
Excluder
1
2
0
3
0
1
No excluder
2
Excluder
3
Excluder
Excluder (1.9%, sd=1.1)
No excluder (2.9%, sd=2.1).
Excluder (8.1%, sd=2.0)
No excluder (11.2%, sd=3.6
p-value=0.048, Mann-Whitney
U-test, n=33
p-value=0.036, Mann-Whitney
U-test, n=8
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IIFET 2000 Proceedings
% Recovery
Cooked % pieces
30
%
% 25
R
e
c
o
v
e
r
y
P 20
i
e 15
c
e 10
s
5
0
35%
30%
25%
20%
15%
10%
5%
0%
1
0
1
No excluder Excluder
No excluder
2
Excluder
3
Excluder 17.5% (sd=6.5)
No excluder 18.4% (sd=5.5)
(p-value=0.60, Mann-Whitney
U-test, n=8).
2
3
4
Research day
5
6
7
8
Excluder
No excluder
Percent recovery was not
significantly different between
excluder and control sides
(p-value=0.92, Mann-Whitney
U-test, n=8).
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IIFET 2000 Proceedings
Conclusions
Based on these findings, it is concluded that
finfish bycatch does contribute to the breakage of
ocean shrimp.
However, the impact is small relative to
breakage caused by other handling procedures.
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