Untitled - CNR

Fishery and Sea ResourcesAnguilla anguillaChelon labrosusDiplodus vulgarisLiza aurataLiza ramadaLiza saliensMugil cephalusSparus aurataSep Oct Nov Dec Jan Feb Mar Apr MayFigure 7: Recruitment calendar of marine species captured in tidal channels during studyperiod. Present, grey; abundant, black.open sea, thus affecting recruitment patternsthrough the two tidal channels.In addition, the inadequate maintenance ofthe structures in the tidal channels (mechanicalsluices often encrusted with foulingorganisms and grilles occluded withweeds) clearly constitutes an obstacle tothe entrance of recruits, preventing theproper exchange of waters between the seaand the lagoon basin and further reducingthe “appeal” of the lagoon to juveniles ofeuryhaline marine species. The presenceof the landing stage for fishing boats at theseaward end of the Acquarotta Channel,where the highest number of recruits wasobserved, may also constitute a factor ofdisturbance for the entry of fish juvenilesinto the lagoon.This study enabled us to verify the migrationcalendar of economically importantmarine species entering Lesina Lagoon(Figure 7). The data obtained are comparableto those already available for the samestudy area [25, 24]. On the other hand,differences were observed with respect tobrackish areas along the northern Adriaticcoasts of Italy [27] and the coasts of Greece[29], where recruitment of L. aurata and L.ramada peaks in spring. This discrepancymay be due to differences in the distancebetween the coast and the reproductive areasand to local climatic factors [1].All species except L. aurata showed onecohort, which is the result of a singlespawning event. In contrast, the two cohortsof L. aurata may be the result of twospawning events of different intensities orof a single protracted spawning event.In the lagoon basin, the distribution ofYOY marine fish was not uniform acrossstations. L. aurata, L. ramada, L. saliensand M. cephalus juveniles showed a clearpreference for the area near the mouth ofthe Pilla Channel (station 5). High abundancesof L. ramada and M. cephalus juvenileswere also found at stations 1 and7, located near the mouths of the CannelleChannel and the Zannella River, where effluentis discharged from buffalo and fishfarms. These findings indicate that theseareas function as nursery grounds for thesetwo species. Moreover, high abundances ofL. ramada, L. saliens and M. cephalus juvenileswere found at stations 2 and 9, nearthe tidal channels, where they are assumedto have been in transit towards the nurserygrounds. In a recent study on the spatialtemporalvariations of chemical-physicalparameters, nutrients and phytoplankton inLesina Lagoon, Roselli et al. [23] observed2110