Beam Trawling

Question 1

When was beam trawling introduced?

Answer 1

Latter part of 19th century

Question 2

What countries use beam trawling?

Answer 2

Dutch, Belgians, English and growing interest in North and east Scotland

Question 3

Where does beam trawling take place?

Answer 3

Sometimes operated by small boats by inshore fisheries where modern otter trawl is too large

Question 4

How is the beam trawl net held open?

Answer 4

-Held open by rigid framework that maintains its shape
-Made it ideal for towing behind early sailing boats with unpredictable course and speed

Question 5

Where is the beam trawl on the boat?

Answer 5

Modern boats
-Tow two beam trawls from long derricks projecting over each side of vessel
-Early days
trawling only one net from stern

Question 6

How long is the haul duration for beam trawling?

Answer 6

Usually two hours

Question 7

What depths are fished by beam trawls

Answer 7

100 m

Question 8

What species are fished with beam trawling?

Answer 8

Internationally 75% of flatfish like plaice, sole, turbot and brill
-Shrimp
North Sea and Irish Sea flatfish fishery is carried out with beam trawls

Question 9

How long can the beam be?

Answer 9

12 m

Question 10

Describe the structure of the beam trawl?

Answer 10

-Heavy steal beam of tubular section supported by steel beam heads at each end
-Beam heads have wide shoes at the bottom which slide over seabed
-Beam and beam heads form rigid framework that keeps net open

Question 11

Where is the headrope connected to?

Answer 11

The beam

Question 12

Where is the ground rope fastened?

Answer 12

Fastened loosely between bases of the shoes so that it curves backwards

Question 13

What is the purpose of tickler chains?

Answer 13

Placed in front of ground rope to drive flatfish from the sea bottom into the net

Question 14

What are the two types of beam trawls?

Answer 14

-Open gear
-Chain mat gear

Question 15

What is the chain mat gear beam trawl used for?

Answer 15

For towing over harder, rockier areas of seabed
-Usually used by bigger class of beamers

Question 16

Describe a chain mat beam trawl.

Answer 16

Is a rig of lattice work of chains towed from the back of the beam sloping down to the footrope of the net

Question 17

What is the purpose of the lattice work of chains in a chain mat beam trawl?

Answer 17

Guide the trawl over rough ground and boulders on the seabed to minimize damage

Question 18

What is the purpose of flip up ropes?

Answer 18

To prevent stones from entering the net and damaging it.

Question 19

Describe the structure of flip up ropes.

Answer 19

Rope mesh fence towed ahead of the footrope to lift the footrope over obstacles

Question 20

What are some issues with beam trawling?

Answer 20

-Plaice is caught is mixed fisheries with sole in southern North sea using 80 mm mesh size nets
-Result- plaice under minimum of 27 cm landing size which causes high discard rates (50% by weight)

Question 21

Why aren’t beam trawl mesh sizes increased?

Answer 21

-Increasing mesh size would result in less by-catch and discarding of juvenile plaice
-However this would lead to loss of marketable sole

Question 22

What is the approximate size of which 50% of female plaice first spwan?

Answer 22

30 - 34 cm
(EU minimum is 27cm)

Question 23

What are the advantages of beam trawling?

Answer 23

-Effective for flatfish
-Irish sea- catch sole, plaice, lemon sole, (rays and skates by-catch)
-Megrims and monkfish are caught in deeper water

Question 24

What are the disadvantages of beam trawling?

Answer 24

-One of most destructive forms of bottom trawling
-Sea bed is dug up ecosystem is disturbed
-Hundreds of species of no commercial value are killed - large by-catch
-Mortality caused by tickler chains
-Low discard survival
-Fish in net are injured- reduced commercial value

Question 25

How has beam trawling affected the North sea>

Answer 25

Reduced the benthic biomass and production 56% and 21% respectively compared with unfished state

Question 26

What is the discard survival rate of beam trawling?

Answer 26

10% (40% max, but rarely)

Question 27

How many tickler chains can be used at the same time?

Answer 27

26 chains

Question 28

What is the minimum mesh size of beam trawls?

Answer 28

80 - 90 mm

Question 29

What is the EU estimated fishing pressure of trawl fleets?

Answer 29

Two to three times the sustainable level

Question 30

What are some fish retailers doing in regards to beam trawl policies?

Answer 30

-Some are planning to phase out selling beam trawled flatfish