322 
Fishery Bulletin 106(3) 
9°30'W 9°00'W 8°30'W 8°00W 7°30'W 7°00'W 
Figure 1 
Map of the Algarve region and the Barlavento and Sotavento areas where 
the catches of deliberately lost traps of two types were quantified in 1999 
and 2000, and where information on the numbers of traps lost by com- 
mercial fishermen and the reasons for trap loss were obtained by means 
of questionnaire surveys. 
opening at the top (Fig. 3). Murejonas targeting sea 
breams (Sparidae) were baited with approximately 
0.5 kg of crushed common cockle ( Cerastoderma edule). 
The octopus traps located in shallow waters were 
monitored by scuba divers using slates, video, and still 
photography cameras. Acoustic pingers, an acoustic 
receiver, and a GPS differential antenna were used 
to aid divers in locating the experimental traps. Data 
recorded consisted of the number of the trap, number 
and identification of the species captured, as well as an 
estimate of the total length of each individual 
caught. In order to estimate the total catch 
(numbers of fish), traps were also inspected for 
remains of fish that might have died or been 
eaten while inside the traps. The structural 
integrity of the traps was evaluated by divers 
one year after their deployment. 
The catches were analyzed in terms of target 
vs. nontarget and prey (both target and non- 
target) vs. predator species. The target spe- 
cies were common octopus ( Octopus vulgaris ) 
for the octopus traps, and Sparidae (axillary 
seabream ( Pagellus acarne ), common pandora 
(P. erythrinus), striped seabream ( Lithognathus 
mormyrus), annular seabream ( Diplodus annu- 
laris), Senegal seabream ( D . bellottii), common 
seabream (D. sargus), two-banded seabream 
(D. vulgaris), black seabream ( Spondylioso - 
ma cantharus), and blotched picarel ( Spicara 
maena) for the murejona fish traps. Conger 
eel ( Conger conger ), Mediterranean moray eel 
( Muraena helena), forkbeard ( Phycis phycis), 
and O. vulgaris were considered predator spe- 
cies that would feed on trapped small fish and 
in the case of conger and moray eels, also on 
octopus. 
Bail basket 
Entrance 
40 cm 
Bridle 
44 cm 
Figure 2 
View from the top of an iron frame, plastic mesh octopus trap 
(covo) of typical dimensions (40 x 44 x 25 cm) and mesh size (4-cm 
plastic square mesh). 
