bottom trawl fleet, the discard of individuals above legal size is less than 20% by
weight of the catch in the regulated species, with the exception of Pagellus
erythrinus of which 44% by weight of specimens with legal size are discarded. In
species such as Merluccius merluccius, 100% of discards are juveniles, although an
analysis of their size distribution shows that a proportion of individuals traded are
below the legal minimum size. Among the unregulated species, B. boops and
M. poutassou have the highest percentages of discarded specimens with legal size
with 98% and 85% by weight, respectively. The most discarded species was
B. boops, constituting its discard 87% of its catches in weight in 2011 and 97% in
2012. Next in importance is P. acarne, a species that has a great impact on the
catches of the demersal fleet since 75% in weight are small specimens (Figs. 18.32
and 18.33).
0
200
400
600
800
B. boops
P. acarne
T. mediterraneus
T. trachurus
P. erythrinus
M. poutassou
S. scombrus
M. merluccius
D. vulgaris
P. bogaraveo
S. pilchardus
M. barbatus
E. encrasicolus
M. surmuletus
Tons
Discard
Landing
Fig. 18.32 Average total catch (tons) of the retained (commercial) and discarded fraction of the
bottom trawl fleet during the period 2011–2012 (redrawn from García et al. 2015)
620
M. González Aguilar et al.