Ref. Ares(2018)4180323 - 09/08/2018
Ref. Ares(2019)2387732 - 04/04/2019
Annex VIII
Draft exemption for high survivability of plaice caught with beam trawls BT2 in the
Western Waters (7a-k)
The BT2 gear is used in a target fishery on sole and mixed bycatches of for example plaice. The
general introduction of the “Flemish panel” in 2016 already resulted in the reduction of the total sole
catch by 19,7%, and the reduction of undersized sole (< 24 cm) catch by 40,3%. Increasing the mesh
size of the extension in a Belgian beam trawl was shown to be an effective and simple method to
reduce the capture of sole. For the moment, it seems difficult to further increase selectivity in this
fishery without a further loss of marketable sole.
The choke mitigation tool for the North Western Waters (October 2017) indicated that plaice is a
potential choke in different fishing areas. This tool also demonstrated that a high survivability for
plaice in the western waters would largely alleviate the risk of plaice to choke the fisheries concerned.
Specific survivability studies for plaice demonstrate that there exists an extremely high variability in
the results of vessels, ranging from rather low to high levels (4-93% - see annex I, p. 16. More specific
for the western waters the survival levels range from 8 till 73%). This indicates that it is possible to get
high survivability figures and that improvements are still possible. The study in annex I stipulates an
estimation of the high numbers of juvenile plaice that could survive.
Scientists were invited to study the parameters, which determinate survivability. The study conducted
by ILVO in annex I demonstrates significant impacts on survival by trawl duration, sorting duration,
wave height, sea temperature, sediment catch and total catch.
From a policy perspective, it seems possible to manage certain of those elements e.g. trawl duration,
sorting duration, sediment catch and total catch:
1) The study shows clearly that especially the effect of the sediment catch is important. If catches
exists of more than 25% of stones or sand, the survivability of the flatfish caught, decreases by nearly
a factor 10. The avoidance of stones and sand in the cod end should be possible by the use of certain
technical devices. A note on the potential to increase survival of discards by technical measures in
beam trawls (annex II) suggests two technical modifications to beam trawls to avoid stones:
a) the
flip-up rope rigged on top of the bobbin rope in the net opening;
b) the
benthic release panel, a square mesh panel inserted in the belly of the trawl, just in front
of the cod-end. However, the use of the benthic release panel causes again the loss of
marketable sole catches;
The introduction of these devices could therefore have a significant impact to increase further
survivability for plaice in the BT2 fishery for the >221kW segment fleet.
A transitional period would allow researchers to conduct further scientific work to improve the gear
selectivity and to improve survivability of plaice. Note that the use of these devices will also positively
impact other flatfish species in the area. Amongst others an electric benthic release panel could have
some selectivity potential without losing significant quantities of sole.
2) On smaller BT2 vessels, the <221kW segment fleet, the introduction of these technical devices
would hinder fishing operations. Therefore alternative management measures should be explored to
increase the survivability of plaice in this segment.
The study in annex I demonstrates that a reduction of the trawl duration and air exposure time also
has an impact on the survivability.
A transitional period would allow researchers to conduct further scientific work on the possible impact
of trawl duration and focus further on this particular fleet segment.
During this transitional period a limitation of the average trawl duration to less then ninety minutes
seems recommendable. A summary of the exemption is provided in Table 1.
Recommendations:
- A temporary exemption for high survivability of plaice in western waters (7a-k) caught with
BT2 gear is requested for vessels of the >221kW segment fleet which use the flip-up rope or
benthic release panel.
- The smaller BT2 vessels, with an engine power of not more than 221kW or less than 24 m
length overall, which are constructed to fish in the twelve mile zone, could use a temporary
exemption for high survivability for plaice if the average trawl duration is less then ninety
minutes
Table 1: Completed STECF table for high survivability proposal
Country
Exemption
Species as
Number of
Landings (by
Estimated
Estimated
Discard Rate
Estimated
applied for
bycatch or
vessels
landing
Discards
Catch
discard
(species, area,
target
subject to
obligation
survival rate
gear type)
the landing
subject
from
obligation
vessels)
provided
studies
IE
Plaice, VIIa and
Bycatch
13
269
255
524
49%
8-73%
b-k
BE
Plaice VIIa
Bycatch
19
76
NA
NA
NA
Plaice VIId
Bycatch
41
2.108
1.130(*)
3.238 (*)
35% (*)
8-73%
Plaice VIIe
Bycatch
27
148
NA
NA
NA
(50% trips
12-35%)
Plaice VIIf,g
Bycatch
30
170
199
369
54%
Plaice VIIh,j,k
Bycatch
15
11
NA
NA
NA
Note: (*) discard rate 2015 extrapolated on 2017 catches. In the meantime TAC increased substantially in 2016 (nearly doubled) & 2017.
It is also important to note the seasonal pattern in the Belgian plaice landings VIIde. Based upon a 3 yearly average monthly quota uptake, we can
assume that 80% of the BE quota uptake is during the months January – March (53%) and November – December (27%). (See table next page)
Survivability of plaice in VIIde seems to be better in winter time.
(Joint Recommendations NWW2019 Annex VIIIa table 2:
trip 4 (7d) March 2015 survivability 73%;
trip 5 (7d) March 2015 survivability 55%;
trip 14 (7d) November 2017 survivability 30%(**) and
trip 15 (7de) January 2018 survivability 32% (**) .
Note: (**) Predicted survival based on the validated reflex impairment-survival relationship.)
SCHOL in VIIde
JAN
FEB
MRT
APR
MEI
JUNI
JULI
AUG
SEP
OKT
NOV
DEC
JAAR
init.quotum(ruil)
benut
Belgische havens
211
127
84
33
63
99
50
32
29
35
74
342
1.179
Vreemde havens
491
167
57
15
10
25
17
22
28
51
65
265
1.213
Totaal 2016
702
294
141
48
73
124
67
54
57
86
139
607
2.392
Gecumuleerd 2016
702
995
1.137
1.184
1.257
1.381
1.448
1.503
1.560
1.646
1.785
2.392
2.392 2.037 (+535,341)
93%
Gecumuleerd 2015
242
558
708
738
764
813
872
910
967
1.092
1.318
1.710
1.710 1.018 (+844,952)
92%
Gecumuleerd 2014
318
756
1.062
1.100
1.130
1.165
1.200
1.221
1.250
1.305
1.367
1.430
1.430 871 (+567)
100%
Gemiddelde '14,'15,'16
420
770
969
1.008
1.051
1.120
1.174
1.211
1.259
1.348
1.490
1.844
1.844
23%
42%
53%
55%
57%
61%
64%
66%
68%
73%
81%
100%
100%