In accordance with the mesh size of the bag (2a ¼ 110 mm), beam trawls
generaly proved to be selective, the specimens retained being larger than 6 cm
(the minimum size at which R. venosa can be retained is 5 cm).
The increase in R. venosa catches by means of beam trawl fishing by vessels with
length greater than 12 m led by default to a few changes in the structure of the
fishing fleet (an increasing number of multi-functional vessels, in the fleet segment
12–18 m). As such, while in 2013 only 4 vessels belonging to the fleet segment
12–18 m fished with beam trawl, in 2014, their number increased by 6 vessels.
Fig. 23.2 Vessel used for
beam-trawl R. venosa
harvesting: length of 15 m
(a) and 26 m (b) (original)
Fig. 23.3 Beam trawl
(http://slideplayer.com/
slide/10598946/)
23 New Equipment and Technologies Used for Rapa Whelk Harvesting at the. . .
401
generaly proved to be selective, the specimens retained being larger than 6 cm
(the minimum size at which R. venosa can be retained is 5 cm).
The increase in R. venosa catches by means of beam trawl fishing by vessels with
length greater than 12 m led by default to a few changes in the structure of the
fishing fleet (an increasing number of multi-functional vessels, in the fleet segment
12–18 m). As such, while in 2013 only 4 vessels belonging to the fleet segment
12–18 m fished with beam trawl, in 2014, their number increased by 6 vessels.
Fig. 23.2 Vessel used for
beam-trawl R. venosa
harvesting: length of 15 m
(a) and 26 m (b) (original)
Fig. 23.3 Beam trawl
(http://slideplayer.com/
slide/10598946/)
23 New Equipment and Technologies Used for Rapa Whelk Harvesting at the. . .
401