Report from the Commission to the Council on the selectivity in trawl fisheries for cod in the Baltic Sea
Date: 2008-12-16
Institutions: European Commission
Subjects: Baltic Sea, conservation of fish stocks, fishing area, fishing net, fishing regulations, report, technical rule

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COMMISSION OF THE EUROPEAN COMMUNITIES 

Brussels, 16.12.2008 
COM(2008) 870 final 

REPORT FROM THE COMMISSION TO THE COUNCIL 

on the selectivity in trawl fisheries for cod in the Baltic Sea 

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REPORT FROM THE COMMISSION TO THE COUNCIL 

on the selectivity in trawl fisheries for cod in the Baltic Sea 

1. 

AIM AND INTRODUCTION 

Article 7 of Council Regulation (EC) No 2187/2005 for the conservation of fishery resources 
through  technical  measures  in  the  Baltic  Sea,  the  Belts  and  the  Sound  requests  the 
Commission  to  present  to  the  Council  "(…)  on  the  basis  of  the  opinion  of  the  Scientific, 
Technical and Economic Committee for Fisheries (…), an assessment of the selectivity on cod 
of  active  gears  for  which  cod  is  recognised  as  target  species.".  According  to  the  scope  of 
Article 7, only gears used in trawl fisheries are covered.  

The assessment concerns trawls, Danish seines and similar gear with a mesh size ≥ 105mm 
with  either  a  Bacoma  exit  window  or  a  T90  codend  (in  which  the  mesh  in  the  codend  and 
extension piece is turned 90°); those being the two selectivity systems used in the Baltic cod 
fishery.  Detailed  descriptions  of  both  gear  attachments  are  specified  in  the  appendix  of  the 
abovementioned Regulation.  

The  assessment  was  conducted  by  the  International  Council  for  the  Exploration  of  the  Sea 
(ICES)1.  The  Scientific,  Technical  and  Economic  Committee  for  Fisheries  (STECF)2  was 
invited to give its opinion on the assessment. The present report offers a summary of ICES' 
and  STECF's  advice,  as  well  as  a  comparison  of  the  selectivity  of  the  T90  codend  and  the 
Bacoma  exit  window.  It  also  provides  the  rationale  for  increased  selectivity,  a  first  set  of 
suggestions on how this could be achieved, and a way forward. 

2. 

ICES AND STECF CONCLUSIONS AND RECOMMENDATIONS 

ICES  concludes  that  both  designs  by  Bacoma  and  the  T90  are  indeed  selective  and  give 
retention length (L50= 50% of the fish of this length will be retained in the net) equivalent to 
the  current  Minimum  Landing  Size  (MLS)  for  cod  of  38  cm.  There  is  no  clear  evidence  of 
discrepancy in the selectivity between the two gears. Additional remarks from ICES concern 
advantages and disadvantages of the two gears in terms of practicality, perceived benefits in 
fish quality or fuel efficiency. ICES also recommends additional studies and analysis. 

STECF  supports  ICES'  findings  and  concludes  that  it  has  not  been  possible  on  basis  of  the 
available  information  to  answer  the  question  whether  the  Bacoma  and  the  T90  trawls  have 
similar selectivity properties or not. STECF also notes that “the current exploitation pattern 
on  cod  of  the  trawl  fishery  allows  the  exploitation  of  immature  cod.  This  results  in  a 
suboptimal utilisation of the cod stocks in the Baltic. An improved exploitation pattern with 
reduced mortality on juveniles will not only provide for higher yields but also contribute to 
the recovery of the eastern cod stock. Therefore STECF recommends that measures resulting 
in an improved exploitation pattern for Baltic cod be considered.” 

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ICES, 8,3,3,3 (2007). ICES response to EU on selectivity of active gears targeting cod in the Baltic Sea. 
STECF  (2008)  Commission  staff  working  paper:  Scientific,  Technical  and  Economic  Committee  for 
Fisheries advice on selectivity of active gears targeting cod in the Baltic Sea 

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3. 

DETAILED ANALYSIS OF THE ASSESSMENT 

3.1. 

Selectivity  

Conclusions on selectivity are based on an earlier analysis carried out by ICES3, due to lack of 
recent  studies  on  selectivity,  especially  on  Bacoma.  ICES  however  takes  into  account 
preliminary  results  from  two  recent  Polish  and  German  studies  on  selectivity,  mainly 
conducted on T904. 

According to ICES' conclusions, both Bacoma windows and T90 codend give L50 of 38-40 
cm, which is equivalent to the MLS for cod of 38 cm. For T90, the preliminary analysis of the 
German and Polish data give L50s of ~ 41cm and selection ranges of 4.8 to 6.5 cm. Overall, 
no difference in selectivity between the two gears could be detected, but nevertheless, it could 
not be excluded. 

3.1.1.  Role of number of meshes in the cod end circumference 

The earlier analysis made by ICES uses old data sets on T90 codends. The majority of those 
data sets were obtained from experiments using codends with a higher number of meshes in 
circumference than the current legal maximum of 50. However, a modelling analysis recently 
carried out in Denmark5 and other scientific reports indicated that codend circumference has a 
major  bearing  on  selectivity  regardless  of  whether  the  codend  is  constructed  in  standard 
diamond  mesh  or  T90.  A  reduction  in  the  number  of  meshes  in  the  codend  circumference 
dramatically  increased  selectivity.  It  is  therefore  plausible  that  the  selectivity  of  the  T90 
codend determined from the earlier analysis (with higher number of meshes) underestimates 
the current selectivity for T90. The recent studies carried out by Poland and Germany on T90 
as stated above support this theory.  

3.1.2.  Role of volume of catch and catch composition 

Volume  of  catch  and  catch  composition  can  influence  the  selectivity  of  Bacoma  and  T90 
gears respectively. There are indications both from observers and fishermen that the current 
Bacoma  window  works  relatively  well  when  catches  are  smaller  than  approximately  two 
tonnes per haul. When the catches are larger and especially when they are dominated by cod 
around the minimum landing size, the size-selective properties turn to an unsatisfactory result. 
This is in line with previous studies and is related to the size of the Bacoma window.  

For  the  T90,  codend  studies  indicate  that  the  selectivity  is  not  so  dependent  on  volume  of 
catch but more on catch composition. A high concentration of flatfish in the codend decreases 

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ICES  (2004)  Report  of  the  ICES-FAO  Working  group  on  Fishing  technology  and  fish  behaviour 
(WGFTFB), 20-23 April 2004, Gdynia, Poland. ICES CM 2004/B:05.189 pp; ICES (2005) Report of 
the  ICES-FAO  Working  group  on  Fishing  technology  and  fish  behaviour  (WGFTFB),  18-22  April 
2005, Rome, Italy. ICES CM 2005/B:04.283 pp 
Moderhak  W.,  2007.  Selectivity  in  trawl  fisheries  for  cod  –  assessment  of  the  selectivity  on  cod  of 
active gears for which cod is recognised as target species according to Article 7 of Council Regulation 
(EC) No 2187/2005. Communication from Poland to European Commission. 16th August 2007. 
Wienbeck  H.,  2007.  579  Cruise  Report  of  FRV  Solea  from  7/9/2007-28/9/2007.  Institute  for  Fishery 
Technology & Fishery Economics, Hamburg, Germany. In prep. 
Herrmann B., Priour D., and Krag L.A., 2007. Simulation-based study of the combined effect on cod-
end size selection of turning meshes by 90° and reducing the number of meshes in the circumference for 
round fish. Fisheries Research 84 (2007) 222-232. 

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the  selective  property  of  the  net  for  cod.  Therefore  ICES  recommends  that  complimentary 
technical measures, such as real time closure in areas with high concentrations of flatfish or 
undersized cod, be considered.  

3.1.3.  Minimum Landing Size (MLS) 

Both gear options, Bacoma and T90, give L50s equivalent to the MLS for cod of 38cm. 

At  present  L25  (25%  of  the  fish  of  this  length  will  be  retained  in  the  net)  coincides  with  a 
length of cod in the range of around 35-38 cm for both Bacoma and T90 which would be a 
more selective management objective.  

3.1.4.  Discarding  

The estimated amount of discards from all fisheries on both the Western and Eastern Baltic 
cod stocks is provided by ICES' Working Group on Baltic Fisheries Assessment (WGBFAS). 
According  to  their  latest  report6,  discarding  increased  from  1600  tons  in  2005  to  over  4000 
tons  per  year  in  2006  and  2007.  ICES  considers  that  the  likely  cause  of  this  increase  in 
discards is the strong year classes of 2003 and 2005, which joined the catchable stock but was 
just above the MLS.  

The discard rate for the Baltic cod is now estimated to be around 10% of the catch by weight. 
An increased selectivity would reduce this percentage and provide for improved recovery of 
the stocks and higher yields.  

3.2. 

Additional aspects 

3.2.1.  Acceptance among fishermen  

From all available information there seems to be a clear dichotomy in the preference for gears 
between Member States:  

–  Danish and Swedish fishermen clearly prefer to use the Bacoma window;  

–  Fishermen from other Member States, particularly Poland and Germany, consider 

the T90 codend as the more attractive alternative.  

It seems as though neither option is perfect in optimising catches or minimising discards, and 
both are more acceptable for fishermen than a simple mesh size increase.  

3.2.2.  Gear attachments 

Under  Article  5  of  Council  Regulation  (EC)  2187/2005,  several  legal  gear  attachments  are 
described that may have an adverse effect on selectivity or can be rigged in an illegal manner 
to restrict mesh opening. The use of bottom side chafers, large “rescue” floats attached to the 
codline, flappers and round straps, may have an effect on selectivity depending on how they 
are  rigged.  The  continued  need  for  such  attachments  for  strength  and  safety  reasons  should 
thus be balanced against their negative effects on selectivity.  

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ICES CM 2008 / ACOM : 06 

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3.3. 

Follow-up studies recommended by ICES and STECF  

ICES  and  STECF  recommend  carrying  out  studies  in  order  to  increase  knowledge  of  and 
clarify the difference between Bacoma window and T90 codend. The list of studies proposed 
is as follow: 

•  Structured  experiments  specifically  designed  to  compare  selectiveness  between  T90 
codends  and  Bacoma  windows  and  to  evaluate  the  effect  of  twine  thickness,  codend 
circumference and mesh size; 

•  Studies on selectivity with increasing catch size and catch composition with both Bacoma 

and T90 codends;  

•  Investigation  of  the  potential  for  complimentary  technical  measures  such  as  real-time  or 

area closures in the Baltic; 

•  Proper  review  of  the  potential  impact  of  circumvention  through  Member  States' 

information; 

•  Review  of  the  current  regulations  regarding  permissible  gear  attachments  e.g.  chafers, 

rescue floats etc. in order to establish whether there is a continued need for their use.  

4. 

COMMISSION'S CONCLUSIONS 

The  Commission  is  of  the  opinion  that  although  discard  rates  are  comparatively  low  in  the 
Baltic cod trawl fishery, there is scope for increased selectivity and other measures to reduce 
discards.  Taking  into  account  the  STECF  recommendation  that  "measures  resulting  in 
improved  exploitation  pattern  for  Baltic  cod  be  considered",  the  Commission  would  like  to 
explore  the  possibility  of  increasing  selectivity  in  the  Baltic  cod  trawl  fishery  and  avoid 
discards.  

The  Commission  sees  the  current  positive  trend  in  the  Baltic  eastern  cod  stock  as  an 
opportunity  to  increase  selectivity  without  heavy  economic  losses  for  the  Baltic  fishing 
industry.  The  semi-enclosed  Baltic  Sea  with  its  dominantly  single  species  fisheries  also 
constitutes  a  suitable  candidate  for  a  fully-embraced  ecosystem  approach  management  with 
significantly  reduced  discard  levels  of  both  commercial  and  non-commercial  species.  The 
medium  and  longer-term  effects  of  such  approach  should  be  higher  catch  quotas  and 
ecologically and economically healthier fisheries.  

Recently  the  Commission  has  gained  support  from  the  Baltic  Sea  RAC7,8  (BSRAC)  for 
reducing  discards  and  improving  selectivity  in  the  Baltic  Sea.  The  Commission  recognises 
that  there  are  many  possible  measures  for  this  approach  including  expanded  Bacoma 
windows,  increased  mesh  size  in  T90,  increased  mesh  size  in  Bacoma  window,  increased 
mesh size overall, reduced number of meshes in the codend circumference, pilot scheme for 
juvenile cod avoidance, real time closures etc. The Commission welcomes further initiatives 
from Member States and the Baltic Sea RAC in this context and will arrange meetings with 
Member States and the Baltic Sea RAC to discuss pilot projects that would evaluate different 

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BSRAC (2008) Recommendations on the fisheries for Baltic Sea fish species in 2009 
Baltic Sea RAC (2008) Comments on the Commission's consultation paper on discards  

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measures. The Commission will consider the results of pilot projects for reduction of discards 
and  improved  selectivity,  suggest  objectives  and  possibly  new  regulatory  measures,  if  and 
when considered necessary. 

In  this  context,  the  Commission  would  like  to  point  out  that  Council  Regulation  (EC)  No. 
1198/2006 of 27 July 2006 on the European Fisheries Fund, provides several provisions that 
may be used by Member States for the purpose of increasing selectivity. Some examples are 
changes of fishing gear, aid for equipment to reduce the impact on non-commercial species, 
aid  for  smaller  vessels  to  improve  the  management  and  control  of  access  to  certain  fishing 
areas and aid for collective actions such as pilot projects. The Commission therefore invites 
Member States to use the existing means for promotion of pilot projects to improve selectivity 
in the Baltic cod fisheries. 

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