NOTE Erzini et al.: Catches in ghost-fishing octopus and fish traps in the northeastern Atlantic Ocean 
325 
Table 1 
Summary of survey information collected from 84 interviews with skippers: mean depth fished, mean number of traps used by 
the different fleets (local and coastal) in the two areas (Barlavento and Sotavento), and mean numbers of traps lost per year per 
fishing vessel. SD = standard deviation. 
Mean number ( ± SD ) of traps fished Mean number (±SD) of traps lost 
Fleet region 
and area 
Mean (±SD) 
depth (m) fished 
Octopus trap 
Cuttlefish 
trap 
Fish trap 
Octopus 
trap 
Cuttlefish 
trap 
Fish 
trap 
Local (<9 m) 
Barlavento 
Sotavento 
19.1 ±5.7 
21.1 ±5.0 
270.3 ±200.5 
644.4 ±261.7 
149.0 ±145.2 
112.5 ±75.0 
190 ±7.1 
30.9 ±55.5 
145.6 ±102.2 
78.8 ±147.5 
13.5 ±11.1 
13.5 ±10.6 
Coastal (>9m) 
Sotavento 
25.0 ±5.0 
903.8 ±227.7 
80.0 
318.5 ±207.8 
10.0 
Table 2 
Estimates of numbers of octopus traps lost per year off the coast of Barlavento and Sotavento of southern Portugal based on 
national statistics and questionnaire surveys. Fleet was separated into a local and coastal category. Number of licenses was the 
number of trap licenses issued (from national statistics). Number fishing was the number of boats fishing traps (from national 
statistics), Mean number of traps/boat was the mean number of traps fished per year (determined from questionnaires). Total 
number of traps in use was the product of the mean number of traps fished and the number of fishing vessels. Proportion of traps 
lost was estimated from the number of traps lost (from questionnaires) divided by the number of traps fished. Traps lost per year 
was the product of the proportion lost and the total number used. 
Fleet 
Area 
Number of 
Licenses 
Number of 
boats fishing 
Mean number 
of traps/boat 
Total number 
of traps used 
Proportion of 
traps lost 
Number of traps 
lost per year 
Local (<9 m) 
Barlavento 
190 
161 
270.3 
43,518 
0.11 
4975 
Sotavento 
103 
87 
644.4 
56,063 
0.23 
12,667 
Coastal (>9 m) 
Barlavento 
58 
49 
995 
48,755 
0.21 
10,437 
Sotavento 
91 
77 
903.8 
69,593 
0.35 
24,525 
Total 
442 
374 
2813.5 
217,929 
0.24 
52,604 
Although fish traps are relatively less impor- 
tant compared to the octopus traps, they are re- 
stricted to a particular use by the Algarve fishing 
fleet. The use of large fish traps in the Barlavento 
area is favored because of the hard bottom where 
there are larger concentrations of fish. The aver- 
age numbers of traps used per boat for the three 
types of traps commonly used in the fishery, by 
port category (local or coastal) and coastal zone 
area, are given in Table 1. The octopus traps are 
by far the most common of all the traps used. 
We estimated that 52,604 octopus traps were 
lost in Algarve waters in 2000, with the coastal 
fleet accounting for more losses than the local 
fleet, and higher losses in the Sotavento than 
in the Barlavento area (Table 2). Regarding the 
big traps used mostly to catch cuttlefish the local 
fleet lost more such traps than the coastal fleet, 
and there were more losses in the Sotavento than 
in the Barlavento area. 
0 10 20 30 40 50 60 70 80 90 100 
Days after deployment 
Figure 6 
Number of two-banded sea bream ( Diplodus vulgaris ) observed 
in eight different traps over three months. Each symbol rep- 
resents the catches of one trap. 
