Roots are not essential for restoring Posidonia australis using fragments

Restoration of seagrass meadows using naturally-detached rhizome fragments is increasingly important for conservation, yet many fragments lack intact root systems. This study examined whether root removal affects short- to medium-term growth of Posidonia australis fragments under controlled aquarium conditions. Plagiotropic fragments (~12 cm long) that either had their roots intact or roots removed (-roots) were grown in sediment for eight months. Photosynthetic capacity (Fv/Fm) remained consistently high (>0.73) for both treatments throughout the experiment and no significant differences were detected in shoot numbers, leaf length, leaf extension rates, or above-ground biomass. All -roots fragments regenerated root systems, ultimately producing 13% greater below-ground biomass than fragments with intact roots, although this difference was not statistically significant. Results suggests that naturally-detached rootless fragments could be valuable restoration propagules, potentially simplifying transplanting logistics and expanding the range of useable material. Field validation across different seasons and sediment conditions is recommended.