Information Note for vessel owners on use of Swedish Grid or Inclined Separator
gear type in Area VIIA
The EU Fisheries Councils in November and December 2008 adopted a new Cod
Recovery Plan, as set out in Council Regulation (EC) No. 1342/2008 and Annex IIa
of the 2009 TAC and Quota Regulation (EC) No 43/2009. Under these regulations,
Ireland is required to introduce and implement a licensing regime to manage its
allocation of fishing effort – days at sea limits in areas VIa (north west of Ireland) and
VIIa (the Irish Sea) for vessels using specified gear types.
The Recovery Plan is intended to restrict the fishing activity of fishing vessels
operating in either the Irish Sea or the north west of Ireland and Scotland which catch
cod. The effort level was established by the EU Fisheries Council, on the basis of a
EU Commission proposal, based on track record for the average of the period 2005 to
2007 and was then reduced by 25% in 2009 and by a further 25% in 2010. The
impact of this is that there is now limited fishing effort available for all vessels,
including Irish vessels, fishing in the areas.
Under Article 13 of Council Regulation 1342/2008 vessels opting exclusively to use
the Swedish Grid may get an increase in effort for allocation periods in 2010 in Area
VIIa and a possible exclusion from the effort regime from the latter part of 2010 and
those opting to exclusively use the Inclined Separator gear for allocation periods in
2010 in area VIIa may get an increase in effort. The full details are as follows:
The Swedish Grid
The use of the Swedish Grid will allow for an increase in the days at sea allocated in
area VIIa under article 13 of Council Regulation 1342/2008. As it is the only proven
gear (so far) that has achieved catches less than 1.5%, it is expected that vessels
opting exclusively for this gear type and catching less than 1.5% cod, based on the
approach taken in 2009 by the EU Commission, will possibly be excluded from
the effort regime under Article 11 of Council Regulation 1342/2008 from the
latter part of 2010 onwards.
The Inclined Separator
Vessels opting to use the inclined separator panel will receive an increase in the days
at sea allocation for Area VIIa . As this gear has not been proven to reduce cod
catches below 1.5%, it is expected that vessels opting for this gear type, based on the
approach taken in 2009 by the EU Commission, will not be excluded from the effort
regime under Article 11 of Council Regulation 1342/2008 for 2011.
Recognising these are both quite complex gear modification that maybe unfamiliar to
Irish fishermen, this information note is designed to provide guidance on the
specification and installation of the grid or inclined separator panel into a standard
80mm prawn trawl. The grid design is based on the one used in recent BIM trials and
also extensively in Sweden but deviations to this design are permissible under the
definition of a grid given in Appendix 2 to Annex III of EU regulation 43/2009.
Council Regulation (EC) No 1288/2009 extends the legal effect of points (b) (c) (d)
(e) of Appendix 2 to Annex 111 of Regulation (EC) No 43/2009 until 30 June 2011.
The inclined separator panel is based on the design used in the Irish Sea and as
defined in the Annex to EU Regulation 254/2002.
Further information can be obtained from: Dominic Rihan, Marine Technical
Executive, An Bord Iascaigh Mhara, PO Box 12, Crofton Road, Dun Laoghaire Co.
Dublin Tel: 01-144104 Fax: 01-2300564 E-mail: rihan@bim.ie
THE SWEDISH GRID
The grid system comprises the following:
1. Grid
2. Escape Hole
3. Guiding Panel
Escape Hole
Grid
Guiding Panel
1. The grid must be rectangular in shape and has overall dimensions of 150cm in
height x 85cm in width. It can be constructed in any material but is generally
made in tubular aluminium or stainless steel. It can be hinged horizontally in
the middle to make it easier to put on a net drum. The bars of the grid must be
parallel to the longitudinal axis of the grid and the bar spacing must be a
maximum of 35mm. The grid should be mounted at an angle of 45º and must
have all sides attached to the trawl. The easiest way of ensuring the grid is
installed at the correct angle is to mount the lower side along a transverse row
of knots in the bottom sheet, exactly 1m ahead of a top sheet transverse knot
row attached to the top side of the grid. It should be fitted into the straight
extension of the trawl but can be any distance in front of the codend within
this section. In the BIM trials it was fitted into an 8m x100 mesh section x
80mm mesh size section with a total of 174 meshes in the round including
selvedges. Wear and tear on the netting surrounding the grid is reduced by
lashing 10-12mm PP rope around the frame of the grid after installation. For
floatation 4-8 x 8 inch floats or 4 x 11 inch floats should be attached along the
top edge of the grid.
The Swedish grid, constructed of welded aluminium tube (the outerframe (A) 30mm
diameter and inner bars (B) 30mm diameter), the bar space(C) is 35 mm. The grid is
hinged in the middle (D).
2. The escape hole is a triangular opening with a flat apex cut in the top sheet of
the trawl which allows the escape of fish too large to pass between the bars of
the grid. The escape hole is cut from near the corners of the grid (all bar cut)
on the top sheet down into a triangle, leaving five meshes across at its apex.
The exit hole should then be strengthened with nylon twine, pulled tight to
form a triangle.
3. The guiding panel is constructed in the same material as the extension piece
and is designed to direct the catch towards the bottom of the grid similar to a
“flapper”. It is cut on the bar and its forward edge should match the
circumference of the extension piece tapering down to an opening the width of
the grid and with a minimum vertical opening of 15cm and be about 1m in
length. The guiding panel should be secured in the extension in such a manner
that the funnel mouth will be directed to the part of the grid furthest from the
escape hole. The distance between the grid and the funnel mouth is
recommended to be from 0.3-0.5m
FINISHED GRID SHOWING FISH OUTLET AND CHAFING ROPE AROUND
GRID FRAME
Points to note
1. The bar spacing of the Nephrops grid must not exceed 35mm maximum
2. There is no regulation regarding the size of grid and in Sweden grids from 1.31.5m long x 0.6m-1.0m width are used.
3. The 1m spacing between the top and bottom edges of the grid is to maintain a
45º and is based on a 150cm grid. With a smaller grid this distance will be
shorter to maintain the 45º angle of attack. This can be calculated from the
formula below:
Installation length in extension piece (A) = total length of grid (B) x 0.71
In this case A= 150cm x 0.71 = 106.5cm round down to 100cm
4. The biggest difficulties with the grid are reported to relate to handling of the
grid, chafe, knocking fishermen in heavy swell, clearing the grid and
blockages by debris or large fish. Grid blockage clearance can often be
overcome by slowing the vessel for a minute or so to allow the blockage to
clear. A sign that the grid is blocked is when towing speed slows (similarly to
catching a stone).
5. The grid usually needs adjustment / refitting after several months fishing due
to stretching of the netting section. The angle of the grid should also be
checked and adjusted.
6. Grids often have one or more central hinges to allow it to be wrapped on a net
drum.
7. Many fishermen in Sweden believe the guiding panel is unnecessary as
Nephrops stick to the bottom sheet of the trawl. It is optional to fit a guiding
panel.
8. With the grid there is a reduction of between 10-30% in total catch value when
compared to a standard trawl. The value of fish catches will be greatly reduced
between 75-85% with the majority of this reduction from lower catches of
haddock, whiting, monkfish, John Dory, as well as cod. In the BIM trials
prawns made up 66% of the total value of the catch with the standard trawl
compared to 93% with the grid.
DIAGRAM SHOWING TOP AND SIDE VIEWS OF THE GRID
Width of guiding panel
to be same as extension
piece
Escape hole cut allbars to apex of 5
meshes across
Mount grid top and
bottom along a
transverse row of knots
1m apart
TOP VIEW
Extension piece
174 meshes
total
circumference
1 metre
Attach grid at a distance of
1m between the top and
bottom edges of the grid at
angle of 45º
Mount guiding panel into
extension 1:1
SIDE VIEW
INSTALLATION OF THE GRID INTO AN EXTENSION PIECE
..
Top left: The grid is placed inside extension and the top and bottom are laced in 1m apart to set the angle at 45o
Top right: Grid laced in down the sides
Bottom: Angle is checked (45o)
CUTTING OUT THE ESCAPE HOLE IN FRONT OF THE GRID
Right: Escape hole is cut along the bars in the shape of a triangle
Middle: Exit hole apex is cut so the apex is flat with 5 meshes across
Left: Nylon twine used to reinforce strengthening round
RIGGED GRID SHOWING ATTACHMENT OF FLOTATION
Right: Finished Grid Showing escape outlet
Left: Floats rigged for clipping on and off
ON BOARD HANDLING
Left: Using the power block to manoeuvre the grid during
hauling. Note the grid does not pass through the power block
Right: Grid stored on net drum
THE INCLINED SEPARATOR PANEL
The inclined separator panel is designed to separate roundfish species such as
cod, haddock and cod from prawns that tend to fall back in trawls along the
bottom sheet. Whitefish species are released from the trawl by way of an
escape hatch cut in the top of the trawl above the inclined panel.
Escape opening at top
of panel ~ 30 meshes
Inclined Separator panel
with leading edge ~0.3m
from bottom sheet
(Images courtesy of Fisheries Research Services (FRS), Aberdeen. Crown Copyright
2004)
1. The inclined separator panel is inserted as a 50 mesh section into the
last tapered section of the trawl ~12m above the codline.
2. The panel measures ~ 3m long and is set at an angle of approximately
30º to the selvedge of the net.
3. The leading edge of the panel is horseshoe shaped and set 1m into the
bottom sheet.
4. The leading edge is set ~0.3m above the bottom sheet and at the
selvedge should be one third of the width of the top sheet of the net
measured from selvedge to selvedge.
5. An escape hole is cut at the top of the panel of at least 30 meshes x
80mm across, approximately 2.4m stretched width.
6. The panel can be adjusted by taking in meshes if there seems to be too
big a reduction in overall catch. This will adjust the height of the
leading edge relative to the bottom sheet. Some slight modification of
the panel to fit into small trawls maybe required.
7. With the inclined separator panel there will be a reduction of 8-28% in
total catch value. The value of fish catches will be reduced by between
60-70%. The majority of this reduction is from lower catches of
monkfish, cod and John Dory, haddock and whiting. In the BIM trials
prawns made up 64% of the total value of catch with the standard trawl
compared to 82% with the inclined separator panel.
CODEND
60
TOP SHEET
32
15 Long
1m2b/1m2b out
48
BOTTOM SHEET
14 Long
2m2b/1m2b in
38
10 Flymeshes each side
All netting 80mm
Cut 2m/2b-1m/2b
INSTALLTION OF PANEL AND NET PLAN SHOING PANEL DIMENSIONS
AND CUTS
HORSESHOE SHAPED LEADING
LOOKING BACK TO ESCAPE
EDGE
AT TOP OF PANEL
HOLE
FLUME TANK MODEL OF PANEL
PANEL IN TANK SHOWING
SHAPE WHEN TOWING