Recovery of a fast-growing seagrass from small-scale mechanical disturbances: Effects of intensity, size and seasonal timing.

We studied the recovery of the fast-growing seagrass Cymodocea nodosa from disturbances of different intensities (shoots removal or the entire plant), plot sizes (from 0.04 to 1 m2) and in different seasons (spring and autumn) in a shallow coastal bay. We monitored recovery over 27 months and measured plant traits at the end. Shoot density and canopy height recovered faster (1 month) when only shoots were removed compared to when the entire plant was removed (10-25 months). Small areas took longer to recover than large ones, probably due to limited light availability or the accumulation of detritus. Plants disturbed in autumn took 9 months longer to recover than those disturbed in spring. After the 27-month, all plant traits were similar to those of control plots, except rhizome biomass, which was lower. Our results suggest that mechanical disturbances might exert a negative effect on the long-term resilience of seagrasses.