Variation of larval fish distributions associated with variability in the location of a shelf-slope front

Abstract

This study examines the extent of the interaction between the short-time-scale vaiiability in the location of the shelf-slope sahnity front and the species coinposltion and abundance of larval flsh in the NW Mediterranean Three extensive crulses were carned out during spring (May and J u n e 19921, a season charactenzed by high mesoscale vanability Vanations In the posltlon of the shelf-slope front were correlated with large changes in the distrlbutlon and abundance of fish larvae In the 3 surveys, offshore dispersal of fish larvae of shelf-dwelllng species appeared to b e lim~ted by the geographical posltion of the front When the frontal structure was detected over the shelf, the distnbution of larvae of shelf-dwelllng species was confined to the coastal side of the front, while larvae of mesopelagic flsh s p e c ~e s were located on the oceanic side When the front was detected over the slope, it did not act as a b a r r ~e r separating the larval distributions of shelf and oceanic species but ~n s t e a d llmlted the offshore extent of the lalval distribution of shelf species