using 50 mm diamond and 40 mm square mesh codends

to improve the selectivity of the Mediterranean bottom trawl fishery

Target species:
striped red mullet; hake; Norway lobster; red shrimp

Area, Vessel
315 hauls were carried out in the Balearic Islands bottom trawl fishery on fishing vessels in the size and power ranges of 15 - 23 m and 100 - 400 HP.
Gear type:
demersal

Gear modification
The catching performance of codends made of (i) 50 mm diamond mesh and (ii) 40 mm square mesh were compared.


Results:
(i) The 50 mm diamond codend had higher discard rates than the 40mm square mesh codend, especially for the main discards on the shelf (red algae) and on the slope (crustaceans). (ii) The length frequency distributions did not show overall differences between the 50D and the 40S, but the mean length of hake catches below the minimum landing size (MLS) was significantly higher with the 40S (17 cm) than with the 50D (16 cm).
Further information:
enric.massuti@ba.ieo.es; Zapata M.A. F. Ordines and B. Guijarro.- Submitted. Selectivity in a Mediterranean bottom trawl fishery




Citation :
Zapata, M.A., Ordines, F. and Guijarro, B. , 2017. using 50 mm diamond and 40 mm square mesh codends . In O’Neill, F.G. and Mutch, K. (Eds): Selectivity in Trawl Fishing Gears. Scottish Marine and Freshwater Science Vol 8 No 1.