PROTECTION AND RESTORATION OF THE ENVIRONMENT Cumulative impacts from multiple human activities on seagrass meadows in eastern Mediterranean waters: the case of Saronikos Gulf (Aegean Sea, Greece) Maren Myrto Brodersen 1 & Maria Pantazi 1 & Athina Kokkali 1 & Panayotis Panayotidis 2 & Vasilis Gerakaris 2 & Irida Maina 1 & Stefanos Kavadas 1 & Helen Kaberi 2 & Vassiliki Vassilopoulou 1 Received: 3 April 2017 /Accepted: 27 November 2017 # Springer-Verlag GmbH Germany, part of Springer Nature 2017 Abstract Ecosystem-based management (EBM) addresses the fundamental need to account for cumulative impacts of human activities with the aim of sustainably delivering ecosystem services. The Saronikos Gulf, a large embayment of the Aegean Sea, provides a wide range of ecosystem services that are impacted by multiple human activities, deriving from the metropolitan area of Athens (situated at the northeast part of the Gulf). The anthropogenic impacts affect the status of several marine ecosystem components, e.g., seagrass meadows. Cymodocea nodosa meadows are only present at the most confined western part of the Gulf, whereas Posidonia oceanica meadows are mainly distributed in the inner and outer part of the Gulf. The aim of this study is to assess the cumulative impacts from multiple human activities on the seagrass meadows in the Gulf. The main results indicated that most impacted meadows are P. oceanica in the inner part of the Gulf, adjacent to the most urbanized coastal areas, and near port infrastructures. Land-based pollution, as well as physical damage and loss seem to be the main pressures exerted on the meadows. Understanding cumulative impacts is crucial for informing policy decisions under an EBM approach. Keywords Vulnerability . Ecosystem component . Seagrass meadows . Anthropogenic pressures . Cumulative impact . Aegean Sea Introduction Increasing pressures from human activities on the marine en- vironment have led the European Union (EU) to adopt the Marine Strategy Framework Directive (MSFD, 2008/56/EC) aimed at achieving a BGood Environmental Status^ (GES) of EU waters by 2020. Moreover, under the framework of the Marine Spatial Planning Directive (MSP, 2014/89/EU), the health of the ecosystems is considered in parallel with the provision of their services. Both frameworks have adopted ecosystem-based management (EBM) as a central part of their objectives (Article 1 of the MSFD, Article 5 of the MSP). EBM constitutes an integrated management approach that takes into consideration the human interactions within ecosys- tems. It is clear that conflicts arising from human activities and resource uses need to be managed appropriately and their impacts on the marine environment need to be addressed. The Saronikos Gulf (West-Central Aegean Sea) is adjacent to the metropolitan area of Athens, the capital of Greece, and Piraeus (largest port of Greece), and is thus affected by mul- tiple coastal and marine activities. It receives both urban and industrial inputs, while accommodating both tourism and fish- eries’ activities. The impacts of these pressures on the marine ecosystems of Saronikos Gulf, and particularly on habitats of high conservation priority such as seagrass meadows (Posidonia oceanica and Cymodocea nodosa), have been ex- tensively studied throughout the last decade (Lardi et al. 2015; Gerakaris et al. 2017). These seagrass meadows provide a variety of ecological services such as marine biodiversity maintenance, regulation Responsible editor: Thomas Hein * Maren Myrto Brodersen marenb@hcmr.gr 1 Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, PO BOX 712, 19013 Anavyssos, Greece 2 Hellenic Centre for Marine Research, Institute of Oceanography, PO BOX 712, 19013 Anavyssos, Greece Environmental Science and Pollution Research https://doi.org/10.1007/s11356-017-0848-7