ENVELOPE-TYPE CONSTRUCTION OF THE CODENDS USED IN FISHERIES

• PROPOSAL OF NEW CONSTRUCTION

FOR T90 AND BACOMA CODENDS

Krzysztof Stanuch , Andrzej Boczkowski

Seminarium Dziwnów 12.08.2015

BACOMA CODEND

A. extension piece

B. codend

C. Escape window , square mesh panel

1 upper panel max 50 open diamond meshes

2 lower panel max 50 open diamond meshes

3 selvages

4 joining round or lacing

5 lifting strap

6 back strap

7 codline

8 distance of window from codline

9 buoy rope

10 codend buoy

production of BACOMA codend

codline gathers all meshes

to one point of codend

T90 codend

T90 codend

MESH OPENING IN REAR PART OF CODEND

shape of mesh in VI row

shape of mesh in I row

MESH OPENING IN REAR PART OF CODEND

shape of mesh in VI row

shape of mesh in I row

… according to ICES conclusions , both BACOMA windows and T90 codend give L50 of 38-40cm, 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 41 cm and selection ranges of 4,8 to 6,5 cm. Overall no difference in selectivity between the two gears could be detected , but nethertheless, it could not be excluded.

REPORT FROM THE COMISSION TO THE COUNCIL on the selectivity in trawl fisheries for cod in the Baltic Sea COM(2008) 870

• what more we can do to minimize the problem of discards ?

•The gear selectivity reached and even exceeded the MLS of 38 cm

NEW PROPOSAL OF ENVELOPE-TYPE CONSTRUCTION OF THE CODENDS SHOULD DECREASE SELECTION RANGES AND BY THE SAME SHOULD DECREASE DISCARDS OF UNWANTED FISH !

NEW ENVELOPE CODEND upper/lower panel

proper cut in wedges in the rear part of codend gives

the square meshes in this part, fully opened all the time

during towing

These meshes are turned by 45° in relation to the

selvages, thus have the same pattern as in BACOMA

window.

NEW ENVELOPE CODEND upper/lower panel

proper cut in wedges in the rear part of codend gives

the square meshes in this part, fully opened all the time

during towing

These meshes are turned by 45° in relation to the

selvages, thus have the same pattern as in BACOMA

window.

„ENVELOPE-TYPE” ENDING OF THE CODEND

according to new construction

selvage

Advantages of a new design

• better selectivity without mesh size increase • higher escape level of undersized fish • discards reduction • reduction of the gear selectivity range • better water flow in the trawl and codend • universalism • simplicity of the design • low cost of the required changes • for implementation in almost every type of codends

what next?

•Consultation with fisherman in order to adapt the design to the constructions currently in use; •Research with the use of fishing vessels; • presentation of the research results; • implementation.

Thank you