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238 M. Gristina, M. Gagliano / Fisheries Research 67 (2004) 235–239
choice of the set of the individuals used in the present
study (size, sex ratio), and the standardisation of the
fishing procedures (soak time, bait) permitted us to ex-
perimentally control the main variables that could po-
tentially affect the catch performance of the two trap
types. Accordingly, the present study investigated the
catch performance of traps constructed of two differ-
ent materials. In this study, no significant differences
were found in the catch performances of plastic and
rush traps. The two traps did not show significant dif-
ferences in the catch rate either in relation to biomass
or individual abundance.
It has been suggested that lobsters perceive traps as
shelters (Munro, 1974) and that type of material used
in their construction could affect their attractiveness to commercial lobster fishing. Substituting trammel nets
lobsters. The fact that there was no difference in bait
consumption between the two trap types suggests that
lobsters perceive the two traps in the same way and
that the different materials used in their construction
do not affect the choice of the lobsters. The lack of
escaped specimens during the soak time from both the
traps adds further evidence to this observation.
Ancillary features of the traps, such as colour, mesh
size and form, which may change the “visibility” of
the gears and modify their attractive power (Mahon
and Hunt, 2001) did not seem to influence the results
of our trial. However, we acknowledge that laboratory
conditions do not mirror field conditions (Miller and
Addison, 1995; Zhou and Shirley, 1997). Additional
experiments in the field comparing the fishing effi-
ciency of the two trap types and the suitability of plas-
tic traps as a replacement to the traditional rush type
are advised. Further studies on different life stages of
P. elephas are also advised and may be particularly
pertinent where immature, buried females and larger
males are concerned (Goñi et al., 2001; MacDiarmid
and Butler, 1999).
5. Conclusion
In the past two decades, the durability, longevity
and competitive costs of synthetic materials has con-
tributed to an extensive modification and modernisa-
tion of lobster traps (Krouse, 1989). To date however,
Sicilian lobstermen appear to remain suspicious of
new technologies and prefer trammel nets because:
(1) trammel nets provide higher total catch rates than
traps; (2) the manufacturing and maintenance of tra-
ditional rush traps is expensive and time consuming;
(3) only few old fishermen are able to produce tra-
ditional traps and this art has not been handed down
to new generations. However, the strong decline of
the spiny lobster stock observed in the Mediterranean
fishery (FAO, 1997), particularly in Sicily, illustrates
the need for the introduction of fishing gears that are
consistent with sustainable fisheries and conservation
practices whilst still maintaining current catch rates.
The low costs associated with plastic traps, coupled
with the results presented here, illustrate the abil-
ity of plastic traps to catch lobsters. These features
could provide the incentive to the local community
to re-introduce trapping as the principle means of
by cost effective, selective and non-destructive plastic
traps, would represent an important step in making
the lobster fishery of Sicily a sustainable one.
Acknowledgements
We thank Bart Blaminck of the Acqua Azzurra fish
farm for his generosity, time, patience and enthusiastic
advises on the project. Special thanks are due to Prof.
R. Goñi for the useful suggestions. Additionally, we
thank A. Abdulla, M. Depczynski and G. Di Carlo for
critical discussion and comments, which substantially
improved earlier versions of this manuscript. Finan-
cial support was provided through the Egadi Islands
Marine Reserve.
References
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