Interactive effect of sedimentation and Caulerpa racemosa var. cylindracea invasion on macroalgal assemblages in the Mediterranean Sea

In the present study the effect of the increase in sediment deposition on the spread of Caulerpa racemosa var. cylindracea and the interactive effects of sedimentation and C. racemosa on native macroalgal assemblages have been evaluated. To achieve these objectives a field experiment has been carried out by transplanting of C. racemosa and manipulating sedimentation rates. Results showed that C. racemosa was not affected by an increase of sedimentation rate. The effects of C. racemosa colonization and those of sediment deposition appeared very similar, resulting in a decrease of erect and prostrate species, while turf was not affected. Synergistic mechanisms between sediment deposition and C. racemosa colonization resulted from the strong decrease in percent cover of the main structural species in areas where the two disturbances co-occurred.