Page 6 - Maccarrone_etal_2014

178 V. Maccarrone et al. / Turk. J. Fish. Aquat. Sci. 14: 173-181 (2014)

interaction in the Egadi Island Archipelago was found fishing activity suffered by bottlenose dolphin
to be 77.65 € for 50 m of net in one year. depredation. First, we assessed the PPUE of the
control and pinger nets during 29 hauls. After
Fishing Gear Economic Damage comparing these PPUE values, we obtained the
Advantage of Production for the pinger net. After 29
The levels of net damage suffered by the pinger hauls, the Advantage of Production of 50 m of the
net and the control net after 29 fishing days were pinger net with respect to the control net is 25.69 kg €
similar (Table 3) for total losses of 70.96 € for the h-1 m-1. Based on the difference between the PPUE of
pinger net and 79.07 € for the control net. Table 4 the pinger and the control nets on the day during
summarises the data on the net lost surface and the which dolphin were sighted, we indirectly assessed
equivalent value in Euros for the two types of nets the one-year Economic Damage caused by the loss of
during the 29 fishing days. fish due to the depredation phenomenon. However,
because there was a significant difference in the catch
Discussion and Conclusion obtained by the pinger and control nets, we assumed
that the dolphins never attack the pinger net. Thus,
In this study, we assessed the economic this method could underestimate the ED if we
advantage of the use of a pinger in the artisanal consider that the dolphin “prefer” to attack the control

Figure 3. Trend of the advantage of production of the pinger net during 29 fishing days; the gray bar represents the Dolphin
presence around the fishing nets (interactions).

Table 3. Assessment of the Economic Damage for 50 m of the control net during the fishing season: PPUEInt is the

mean difference between the PPUE of the pinger net and the PPUE of the control net only for the day of the interaction with
dolphins

Target Species ____________ ______ Days freqint ED
kg € day-1 m-1
PPUEInt hour h

kg € h-1 m-1

Boops boops 0.32 2.41 80 0.38 23.41

Sardinella aurita 0.21 2.41 80 0.38 15.20

Trachurus trachurus 0.18 2.41 80 0.38 13.22

Pagellus acarne 0.03 2.41 80 0.38 2.41

Scomber scomber 0.15 2.41 80 0.38 11.27

Spicara maena 0.11 2.41 80 0.38 7.79

Symphodus roissali 0.06 2.41 80 0.38 4.34

Economic Damage (euro) 77.65

(2.41 h) is the mean fishing time per haul, day (n = 80) is the number of fishing days per year, and freqint (0.38) is the interaction ratio
between dolphins and the fishing gear.