Rapido trawling in the northern Adriatic Sea: effects on benthic communities in an experimental area

The rapido is a towed gear used only in the Adriatic Sea for fishing scallops in sandy offshore areas and flatfish in muddy inshore areas. The gear is expected to have a high impact on the entire benthic community, mainly on epifauna and organisms living in the upper sediment layers. To obtain information on likely medium- to long-term effects of trawl fishing in the northern Adriatic Sea, an experiment on immediate/short-term effects was carried out in an undisturbed sandy area near a wreck. The rapido produced flat tracks on the bottom that were still clearly visible after a week by means of sidescan sonar. The trawl did not change the sediment grain size, although it did disturb the upper 6 cm of sediment. Experimental trawling induced a modification in the macrobenthic community that was most evident immediately after the haul. Changes to the meiobenthic community were probably due to sediment disturbance and were recorded after 1 week. Comparison between an undisturbed control area and a neighbouring commercially exploited area allowed some evaluation of long-term changes in the benthic community. (C) 2000 International Council for the Exploration of the Sea.