Untitled - CNR

Marine research at CNRwell defined area, over the time of recruitsconcentration, although characterized byspatio-temporal variability, were identifiedbetween 100 and 300 m. The first one is localizedin the correspondence of C.po Vaticanoand the second one inside the S. EufemiaGulf (Figure 3).The surface occupied by nursery area waslarger in the southern part of the zone (C.poVaticano) than in the northern one (S. EufemiaGulf). The average density of the recruitsrecorded in each survey was statisticallydifferent (ANOVA p < 0.005). Duringthe autumn (GRUND data) two mainpatches were identified. A large nurseryarea between 100 and 300 m has been localizedin the correspondence of C.po Vaticanoand it is quite stable during the year;infact only during 1997 and 2000 surveyit was not found. The highest density ofrecruits was observed in this nursery areaduring 2001 (2662 R·km −2 ). The secondarea, localized inside the S. EufemiaGulf always at depth comprised between100 and 300 m, was observed only in threeyears (1997, 2001 and 2002). The highestdensity of recruits was recorded during2001 (6877 R·km −2 ).4.2 Monitoring No-TakenZones: Gulfs of Patti andCastellammareThe implementation of no-taken zones(NTZs, i.e., areas in which general or specificfishing is temporarily or permanentlyrestricted) might represent a proper managementtools especially in situation of severestocks depletion and conflicts betweenusers. These two basic aims induced theSicilian regional administration in creatingtwo NTZs, in terms of bottom trawlingbanning, in 1990, in the Gulf of Pattiand the Gulf of Castellammare, respectively.The two areas are located alongthe northern Sicilian coasts, and interestedall the shelf bottoms (< 200m) and partof the slope (200-500m). The two areashave been routinely explored by experimentalbottom trawl surveys by the OperativeUnit of CNR of Messina withinboth national (GRUND) and international(MEDITS) programs. The possibility touse bottom trawl surveys routinely carriedout in Italian Seas as a possible tool tomonitor the evolution of protected areashas been evaluated [16]. The shelf haulsperformed in two gulfs, Castellammare andPatti (Northern coast of the Sicily), wherebottom trawling has been banned since1990, were used. The standing stock forthe pooled species and for Pagellus erythrinusshowed high variability but not significanttemporal trend. Mullus barbatusdecreased in both gulfs, although only inCastellammare the trend is significative.The mean size in the catch vs the mean sizeat maturity indicates a better situation forPagellus erythrinus than Mullus barbatus.The impressive stock recovery, observedin the Gulf of Castellammare in the firstfour years after the introduction of the fishingban ([17]), have been likely attenuated(Pagellus) and slightly decreased (Mullus)respectively. These results are anywayin accordance to what observed [18] aftereight year of the ban. The strong year byyear variability, likely reflecting also the interactionbetween the life cycle and the surveyperiodicities [19], can be smoothed outby the analysis of GRUND data.2077