Population dynamics of a fragmented subtidal Zostera marina population affected by shell fishing

This investigation illustrates the spatial and temporal dynamics of a Zostera marina seagrass meadow affected by clam harvesting. Photointerpretation satellite imagery corresponding to years 2007, 2013, 2017 2018, combined with field monitoring in 2019 allowed assessing coverage, population genetic characterization Z. areas impacted non-impacted shellfishing activity. The displayed highly fragmented discontinuous matrix anthropogenically induced periodical disturbance associated bottom raking. A continuous colonization process characterized landscape, where area occupied varied two-fold factor, changes even exceeding 86% some years. Only 740 m2 (ca. 15%) remained vegetated four monitored this investigation. number patches showed large interannual variability, 100% studied, ranging from 58 199, while border effect perimeter/area indicator variation between 1 2. Clearly differentiated patterns were observed shoot density, biomass, flowering density shellfishing-induced different sizes long-term areas. significant pattern differentiation among control populations also found. Our results that as function patch-sizes, thus reinforcing need for approach involving seascape structure patch assess impact disturbances on ecosystems.