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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 traps; (2) the manufacturing and maintenance of tra-
study (size, sex ratio), and the standardisation of the ditional rush traps is expensive and time consuming;
fishing procedures (soak time, bait) permitted us to ex- (3) only few old fishermen are able to produce tra-
perimentally control the main variables that could po- ditional traps and this art has not been handed down
tentially affect the catch performance of the two trap to new generations. However, the strong decline of
types. Accordingly, the present study investigated the the spiny lobster stock observed in the Mediterranean
catch performance of traps constructed of two differ- fishery (FAO, 1997), particularly in Sicily, illustrates
ent materials. In this study, no significant differences the need for the introduction of fishing gears that are
were found in the catch performances of plastic and consistent with sustainable fisheries and conservation
rush traps. The two traps did not show significant dif- practices whilst still maintaining current catch rates.
ferences in the catch rate either in relation to biomass The low costs associated with plastic traps, coupled
or individual abundance. with the results presented here, illustrate the abil-
ity of plastic traps to catch lobsters. These features
It has been suggested that lobsters perceive traps as could provide the incentive to the local community
shelters (Munro, 1974) and that type of material used to re-introduce trapping as the principle means of
in their construction could affect their attractiveness to commercial lobster fishing. Substituting trammel nets
lobsters. The fact that there was no difference in bait by cost effective, selective and non-destructive plastic
consumption between the two trap types suggests that traps, would represent an important step in making
lobsters perceive the two traps in the same way and the lobster fishery of Sicily a sustainable one.
that the different materials used in their construction
do not affect the choice of the lobsters. The lack of Acknowledgements
escaped specimens during the soak time from both the
traps adds further evidence to this observation. We thank Bart Blaminck of the Acqua Azzurra fish
farm for his generosity, time, patience and enthusiastic
Ancillary features of the traps, such as colour, mesh advises on the project. Special thanks are due to Prof.
size and form, which may change the “visibility” of R. Goñi for the useful suggestions. Additionally, we
the gears and modify their attractive power (Mahon thank A. Abdulla, M. Depczynski and G. Di Carlo for
and Hunt, 2001) did not seem to influence the results critical discussion and comments, which substantially
of our trial. However, we acknowledge that laboratory improved earlier versions of this manuscript. Finan-
conditions do not mirror field conditions (Miller and cial support was provided through the Egadi Islands
Addison, 1995; Zhou and Shirley, 1997). Additional Marine Reserve.
experiments in the field comparing the fishing effi-
ciency of the two trap types and the suitability of plas- References
tic traps as a replacement to the traditional rush type
are advised. Further studies on different life stages of Eno, C.N., MacDonald, D.S., Kinnear, J.A., Awos, S.C., Chapman,
P. elephas are also advised and may be particularly C.J., Clark, R.A., Bunker, F.P.-D., Munro, C., 2001. Effects of
pertinent where immature, buried females and larger crustacean traps on benthic fauna. ICES J. Mar. Sci. 58, 11–20.
males are concerned (Goñi et al., 2001; MacDiarmid
and Butler, 1999). FAO, 1997. Fishery statistics. Catches and landings. FAO Fisheries
Series No. 48. FAO Statistics Series No. 134, vol. 80. FAO,
5. Conclusion Rome, 714 pp.
In the past two decades, the durability, longevity Goñi, R., Reñones, O., Quetglas, A., 2001. Dynamics of a protected
and competitive costs of synthetic materials has con- western Mediterranean population of the European spiny lobster
tributed to an extensive modification and modernisa- Palinurus elephas (Fabricius, 1787) assessed by trap surveys.
tion of lobster traps (Krouse, 1989). To date however, Mar. Freshwater Res. 52, 1577–1587.
Sicilian lobstermen appear to remain suspicious of
new technologies and prefer trammel nets because: Gristina, M., Fiorentino, F., Garofalo, G., Ragonese, S., Gagliano,
(1) trammel nets provide higher total catch rates than M., 2002. Gli effetti della protezione sull’aragosta comune
(Palinurus elephas Fabricius, 1787) nella riserva marina delle
“Isole Egadi”. Rapporto preliminare: ID/W.PR./MG-FF-GG-