Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Taking advantage of seagrass recovery potential to develop novel and effective meadow rehabilitation methods Adriana Alagna a,b, ⁎ , Giovanni D'Anna a , Luigi Musco b , Tomás Vega Fernández b , Martina Gresta c , Natalia Pierozzi c , Fabio Badalamenti a,b,d a CNR-IAS, Institute for the study of Anthropic Impacts and Sustainability of the Marine Environment, Via G. da Verrazzano 17, 91014 Castellammare del Golfo, TP, Italy b Stazione Zoologica Anton Dohrn, Integrative Marine Ecology Department, Villa Comunale, 80121 Naples, Italy c Saipem S.p.A., via Martiri di Cefalonia 67, 20097 San Donato Milanese, MI, Italy d School of Geosciences, Grant Institute, King's Buildings, University of Edinburgh, Edinburgh, United Kingdom ARTICLE INFO Keywords: Restoration Conservation Habitat Substrate Ecological engineering Posidonia oceanica ABSTRACT Seagrasses are among the most threatened biomes worldwide. Until now, seagrass rehabilitation success has reached about 38% overall and more effective approaches to restoration are urgently needed. Here we report a novel method to rehabilitate Posidonia oceanica meadows based on observation of the species' natural recovery after disturbance. Posidonia oceanica rhizomes were transplanted on gabions filled with rocks of selected sizes in order to build a firm substrate with topographic complexity in the relevant scale range to propagules. Five techniques were tested, each involving a different anchoring device. The “slot” technique, which uses a wire-net pocket to retain the cuttings, was the most successful, with survival exceeding 85% after thirty months. Branching allowed final shoot survival to reach 422% of initial planting density. This study shows how an in- depth knowledge of species life history processes provides a suitable foundation for developing effective re- storation methods that benefit from species recovery ability. 1. Introduction In the last decades, seagrass systems have undergone global re- gression due to overexploitation of marine resources, coastal develop- ment, water quality degradation and climate change, with a decline rate increasing from 0.9% yr -1 before 1940 to 7% yr -1 since 1990 (Waycott et al., 2009; Orth et al., 2006). Meadow regression entails loss of associated high-value ecosystem services including nutrient cycling, protection against coastal erosion, carbon sequestration and support of diverse and productive biological communities whose cost was esti- mated at ~US$ 3.8 trillion year -1 (Costanza et al., 1997; Vassallo et al., 2013; Duarte et al., 2013). The growing awareness of the environ- mental, economic and social benefits provided by seagrass systems at a global scale has prompted policymakers to increase efforts for their conservation and to implement proper management strategies (the Ramsar Convention, the Great Barrier Reef Marine Park Act, the Bern Convention, the Barcelona Convention and SPA/BIO protocol, the EC Habitat Directive (92/43/CEE)and the Marine Strategy Framework Directive (MSFD) (2008/56/EC) ). It is now evident that restoration and rehabilitation actions should be integrated within seagrass management strategies to allow or speed up recovery of degraded meadows from disturbance, with the final aim of re-establishing functional and self-sustaining habitats (Fonseca, 2011; Bell et al., 2008). The overall success of seagrass restoration reaches about 38% worldwide (Bayraktarov et al., 2016) and a recent review on restoration actions undertaken in Europe reveals that the success of transplantation is very low, with an average transplant sur- vival of 15% (Cunha et al., 2012). Moreover, positive outcomes of re- storation actions are assessed over periods shorter than 1 year, which is considered unsuitable for monitoring restoration success, especially for long-living seagrass species (Cunha et al., 2012). Re-establishing seagrass meadows is particularly challenging and costly (Bayraktarov et al., 2016). The success of restoration actions may be impaired by specific intolerance to transplantation, limited https://doi.org/10.1016/j.marpolbul.2019.110578 Received 7 March 2019; Received in revised form 6 September 2019; Accepted 7 September 2019 ⁎ Corresponding author at: CNR-IAS, Institute for the study of Anthropic Impacts and Sustainability of the Marine Environment, Via G. da Verrazzano 17, 91014 Castellammare del Golfo, TP, Italy. E-mail address: adriana.alagna@szn.it (A. Alagna). Marine Pollution Bulletin 149 (2019) 110578 0025-326X/ © 2019 Elsevier Ltd. All rights reserved. T