Letter to the editor regarding the article “Taking advantage of seagrass recovery potential to develop novel and effective meadow rehabilitation methods“ by Alagna et al., published in Marine Pollution Bulletin, 149: 2019 (110578)

Alagna et al. (2019) suggest new transplantation methods for Posidonia oceanica (Linnaeus) Delile, inspired by its natural recovery process after disturbance due to dredging operations for gas-pipelines. They observe that P. oceanica vegetative fragments naturally settled only on loose calcareous stones deployed to fill the trenches of the gas-pipeline. No recovery was noted on dead matte, sand and large calcarenitic boulders. Following a new pilot restoration project currently ongoing in the same area, we demonstrate that natural recovery also occurs on dead matte. After examining other alternative transplantation methods for P. oceanica, the Authors suggest using their "habitat enhancement units" method for the restoration of seagrasses, not only on rocky bottom but also on sand and other bare substrate requiring general environmental restoration. Here we express disagreement on certain issues reported in the paper.