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Catches in ghost-fishing octopus and fish traps 
in the northeastern Atlantic Ocean 
(Algarve, Portugal) 
Karim Erzini (contact author) 
Luis Bentes 
Rui Coelho 
Pedro G. Lino 
Pedro Monteiro 
Joaquim Ribeiro 
Jorge M. S. Goncalves 
Email address for K. Erzini: kerzini@ualg.pt 
Centro de Ciencias do Mar (CCMAR), 
Universidade do Algarve, 
8005-139 Faro, Portugal 
Ghost fishing is the term used to 
describe the continued capture of fish 
and other living organisms after a 
fisherman has lost all control over the 
gear. Traps may be lost for a variety 
of reasons including theft, vandalism, 
abandonment, interactions with other 
gear, fouling on the bottom (i.e., traps 
and ropes are caught on rocky sub- 
strate), bad weather, and human error 
(Laist, 1995). Annual trap loss can be 
as high as 20% to 50% of fished traps 
in some fisheries (Al-Masroori et ah, 
2004). Because lost traps can con- 
tinue to fish for long periods, albeit 
with decreasing efficiency over time 
(e.g., Smolowitz, 1978; Breen, 1987, 
1990; Guillory, 1993), ghost fishing is 
a concern in fisheries worldwide. 
Few studies on the ghost fishing of 
lost traps have been carried out in 
European waters, and there has been 
no information from southern Euro- 
pean waters. Ghost fishing of parlour 
pots used to catch lobsters and crabs 
off the south-west coast of the United 
Kingdom was studied by Bullimore 
et al. (2001), and Godpy et al. (2003) 
carried out an experimental study on 
much larger, deliberately lost pots for 
red king crab ( Paralithodes camts- 
chaticus ) in Norwegian waters. In 
both cases the effect of ghost fish- 
ing by parlour pots was deemed to 
be relatively small compared to the 
effects of other types of traps used 
in Canadian and American fisheries 
(Brown and Macfadyen, 2007). 
In southern Portugal, pots and 
traps of various types are among the 
most widely used gears in the small- 
scale fisheries. Fishing vessels <9 m 
(local category) can legally fish up 
to 500 traps, and coastal category 
vessels (9-12 m and >12 m in total 
length) are allowed up to 750 and 
1000 traps, respectively. The most 
widely used traps in the Algarve are 
1) metal frame, hard plastic netting, 
single entry traps for octopus (covo), 
2) large, metal frame traps for catch- 
ing cuttlefish and fish (armadilha), 
and 3) wire traps (murejona) for 
catching fish. However, only the covo 
traps and murejona traps were used 
in our study. 
Under the Common Fisheries Pol- 
icy and the European Community 
directive on habitats and species, 
member states are responsible for lo- 
cal fisheries and are obliged to take 
measures to minimize or mitigate 
the negative effects of fishing activ- 
ity. Concern over the effects of lost 
gear in European waters has led the 
European Commission to finance two 
pan-European projects on ghost fish- 
ing. The first project focused only on 
gill nets and trammel nets (Erzini et 
al., 1997), and the second project in- 
cluded studies on lost traps in several 
European areas (Godpy et al., 2003). 
Here we report the results from one 
of the studies carried out with two 
types of traps in the northeast Atlan- 
tic (south coast of Portugal) (Fig. 1). 
The catches of deliberately lost traps 
were monitored and estimates of the 
number of trap losses and causes of 
trap losses were obtained through 
surveys of commercial fishermen. 
Materials and methods 
Catches in deliberately lost traps 
The main gear used to catch octopus is 
the octopus trap (covo), a small metal 
framed trap with a single entrance 
on the top (Fig. 2). To make escape- 
ment more difficult, the entrance is 
partially blocked by plastic strips that 
are easy to push through when enter- 
ing the trap but not when exiting. A 
total of 60 octopus traps, each baited 
with two sardines, were deployed on 
August 11, 1999, at two sites off Faro 
where normal fishing activities with 
octopus traps takes place. The depth 
at one site was 20 m, and 50 m at the 
other, and both were situated near 
rocky reefs. At each location 30 traps 
were deployed, 15 on soft bottom and 
15 on rocky bottom. Because the traps 
set at 50 m were difficult to retrieve 
with a grapnel from the hard bottom 
or were all lost within one month after 
deployment (on soft bottom), an addi- 
tional 30 octopus traps were deployed 
at the shallower depth on soft and 
hard bottom on 18 May, 2000 and 
were monitored weekly for 14 weeks. 
In addition to the 90 octopus traps, 
10 fish traps of the murejona type 
were also deployed on 25 May 2000 
at the shallower site (20 m depth) 
and monitored by scuba divers on 
a weekly basis for three months. 
Murejona traps are round, wire 
traps with a single funnel-shaped 
Manuscript submitted 9 July 2007. 
Manuscript accepted 25 March 2008. 
Fish. Bull. 106:321-327 (2008). 
The views and opinions expressed or 
implied in this article are those of the 
author and do not necessarily reflect 
the position of the National Marine 
Fisheries Service, NOAA. 
