Tes$ng of two industrydesigned BRDs to reduce Pacific halibut bycatch Mark J.M. Lomeli Pacific States Marine Fisheries Commission Newport, OR W. Waldo Wakefield FRAM, NWFSC, NMFS, NOAA Fisheries Newport, OR F/V Miss Sue Newport, OR Foulweather Trawl, LLC Newport, OR 29 th Lowell Wakefield Fisheries Symposium 1316 May 2014 Anchorage, AK
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Tes$ng of two industry-‐designed BRDs to reduce Pacific halibut bycatch
Mark J.M. Lomeli Pacific States Marine Fisheries Commission Newport, OR
W. Waldo Wakefield FRAM, NWFSC, NMFS, NOAA Fisheries Newport, OR
F/V Miss Sue Newport, OR
Foulweather Trawl, LLC Newport, OR
29th Lowell Wakefield Fisheries Symposium 13-‐16 May 2014 Anchorage, AK
West Coast Limited Entry Groundfish Trawl Fishery
• Managed under a Catch Shares / IFQ Program – establishes ACLs, IFQs, and IBQ for Pacific halibut – 100% observer coverage
• Groundfish boKom trawl fishery – Dover sole/thornyheads/sablefish are targeted over the cont. slope
(know as the deepwater DTS complex fishery)
– over the cont. shelf, fishermen target a variety of species including flaSishes, rockfishes, roundfishes, & skates
Concern Over Pacific Halibut Bycatch
• Limited quota is available relaXve to the more abundant and more producXve flaSish and roundfish stocks targeted
• For example, 2014 ACLs vs IBQ – Dover sole = 25, 000 mt – English sole = 5,646 mt vs Pacific halibut = 78 mt – petrale sole = 2,652 mt – sablefish = 2,038 mt
• RetenXon of trawl-‐caught halibut is prohibited, therefore must be discarded at sea – before discarded, an observer assigns the fish to a mortality category of
excellent (20%), poor (55%), or dead (90%) – this % mortality (by weight) is then deducted from the fishermen’s IBQ
Industry-‐Designed BRDs Evaluated
• The BRDs evaluated were flexible sorXng grid excluders – Concept: fishes smaller than the sorXng grids will pass through and
move ae towards the codend, whereas fish larger than the grid opening will be excluded
• 1) Developed for the deepwater DTS complex fishery for reducing halibut bycatch
• 2) Developed for the nearshore flaSish fishery for reducing halibut and roundfish bycatch (i.e. overfished and rebuilding rockfishes, juvenile sablefish) – Vessels targeXng Dover sole, petrale sole, English sole, Pacific
sanddad, etc.
Gear Trials • Fishing occurred off Oregon aboard the F/V Miss Sue in 2013
• Tow dura$ons were set to 45 min. – Towing speed ranged from 2.2-‐2.6 knots
• Fish reten$on/escapement was quan$fied using a recapture net, with length and weight data being collected on halibut and species of commercial importance
• Deepwater DTS Complex Fishery: – 23 tows were conducted; avg. bo\om depth = 301 m
• Nearshore Fla^ish Fishery: – 15 tows were conducted; avg. bo\om depth = 189 m
escape tube of netting
intermediate section codend
debris panel Flexible sorting grid 5.5 x 6.0” (14.0 x 15.2 cm)
BRD
Deepwater DTS Complex Fishery BRD
1 2 intermediate
section codend
Nearshore FlaSish Fishery BRD Grid size = 1.75 x 8.5” (4.4 x 21.6 cm)
Top view Camera view
Deepwater DTS Complex Fishery Results
Pacific Halibut Bycatch ReducXon
Trawl Recapture net Result
Number of fish 18 52 74.3%
Weight (kg) 95.0 486.7 83.7%
Mean length (cm) 76 (±1.6 SE) 90 (±1.9 SE) P<0.0001
length (cm)60 70 80 90 100 110 120 130 140 150
weig
ht (k
g)
0
5
10
15
20
25
30
35Recapture net (n=52)Trawl (n=18)
Halibut Size SelecXvity
length (cm)60 70 80 90 100 110 120 130 140 150
weig
ht (k
g)
0
5
10
15
20
25
30
35Recapture net (n=52)Trawl (n=18)
Halibut Size SelecXvity
> 8 KG; 100%
length (cm)60 70 80 90 100 110 120 130 140 150
weig
ht (k
g)
0
5
10
15
20
25
30
35Recapture net (n=52)Trawl (n=18)
Halibut Size SelecXvity
Size SelecXvity for Halibut < 8 kg
length (cm)60 65 70 75 80 85 90
wei
ght (
kg)
2
3
4
5
6
7
8
9
10Recapture net (n=24)Trawl (n=18)
length (cm)60 65 70 75 80 85 90
wei
ght (
kg)
2
3
4
5
6
7
8
9
10Recapture net (n=24)Trawl (n=18)
Size SelecXvity for Halibut < 8 kg
5-8 KG; 70%
length (cm)60 65 70 75 80 85 90
wei
ght (
kg)
2
3
4
5
6
7
8
9
10Recapture net (n=24)Trawl (n=18)
Size SelecXvity for Halibut < 8 kg
< 5 KG; 25%
Halibut Escapement per Tow
tow
1 3 5 7 9 11 13 15 17 19 21 23
weig
ht (k
g)
-20
-10
0
10
20
30
40
50
60 Recapture netTrawl
Halibu
t
Rex so
le
Arrowtoo
th
Dover
sole
Petrale
sole
SSTH
Rough
eye r
f
Sablef
ish
Lingc
od
Big sk
ate
Long
nose
skate
% re
tent
ion
0
10
20
30
80
90
100
RetenXon by Weight (kg) Total catch / tow: 131 – 3,762 kg
• Two BRDs were shown to reduce Pacific halibut bycatch while maintaining catches for several target species
• Deepwater DTS Complex Fishery: – posiXve results were observed overall, however, the gear’s ability to retain larger-‐sized ($) sablefish could affect fishermen’s voluntary use of this BRD
• Nearshore FlaSish Fishery: – encouraging results were observed – further tesXng of this BRD is scheduled to begin at the end of this month
Acknowledgments • NOAA Fisheries Bycatch ReducXon Engineering Program
• PSMFC and NWFSC
• F/V Miss Sue and F/V Excalibur
• Foulweather Trawl, LLC
• Victor Simon (NWFSC FRAM) collaboraXng on the set up of a wireless back deck
• Although viability was only assessed for halibut, most fish caught in the recapture net appeared to be in good condiXon with the excepXon to rockfishes
• Small recapture net catches and short tow duraXons likely contributed to the excellent condiXons noted
Viability Category % Excellent condition excellent poor dead
Trawl 13 1 4 72.2 Recapture net 51 0 1 98.0 Total 64 1 5 91.4