Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Assessing marine environmental status through microphytobenthos assemblages colonizing the Autonomous Reef Monitoring Structures (ARMS) and their potential in coastal marine restoration Chiara Pennesi a,⁎ , Roberto Danovaro a,b a Department of Life and Environmental Sciences, Polytechnic University of Marche, via Brecce Bianche, 60131 Ancona, Italy b Stazione Zoologica Anton Dohrn, Naples, Italy ARTICLE INFO Keywords: Artificial substrates Diatoms Marine environmental status Marine monitoring Microphytobenthos ABSTRACT Microphytobenthos is potentially highly sensitive to environmental alterations, but has been rarely utilized in monitoring studies. Here we investigated the use of microphytobenthos colonizing Autonomous Reef Monitoring Structures (ARMS) to assess the marine environmental quality. We analysed microphytobenthic assemblages in terms of abundance, biomass and species composition on ARMS deployed in northern Adriatic Sea along a gradient of increasing impacts. We show that microphytobenthic variables changed significantly across sites, with lowest abundance and biodiversity in the highly impacted site. Moreover, the specific analysis of Diatoms revealed that genera like Entomoneis and Cylindrotheca could be used as indicators of nutrient enriched and stressed conditions. We provide evidence that the analysis of microphytobenthos colonizing artificial substrates could be used as a tool for detecting altered environmental characteristics. We also show that the ARMS, re- creating hot spots of microphytobenthic biodiversity, and protect them from grazing, could be potentially uti- lized to restore degraded hard substrates. Our result indicates that microphytobenthos can be easily incorporated in future monitoring and restoration programmes to assess and improve marine environmental health. 1. Introduction Microphytobenthos (MPBs) is composed by unicellular eukaryotic algae (i.e., Bacillariophyceae, Chlorophyceae and Dinophyceae), and autotrophic prokaryotes (Azovsky et al., 2013). Microphytobenthos is composed by highly productive phototrophic taxa and represent one of the most important and widespread component of marine primary production at global scale (Underwood and Kromkamp, 1999). The ecological importance of the microphytobenthos assemblages in marine ecosystems is due to the: a) their role in benthic primary production; b) the relevance as food for grazers and deposit feeders (De Jonge and Van Beusekom, 1992; Defew et al., 2002; Miller et al., 1996); c) the effects on sediment properties (through the production of extracellular poly- meric substances, EPS; Ubertini et al., 2015; Underwood and Paterson, 2003), and d) the role on nutrient and oxygen fluxes across sediment- water interface. The analysis of microphytobenthic assemblages can provide im- portant insights into the assessment of marine environmental status and of the impact of global change (Dura et al., 2016; Kostecki and Janczak- Kostecka, 2012; Lobban and Jordan, 2010; Recasens et al., 2015; Rioual et al., 2007; Romero and Armand, 2010; Vegas-Vilarrúbia et al., 2013). These microalgae are considered useful indicators of environmental alteration for their short life cycles and quick response to abiotic and biotic changes (Chen et al., 2016; Potapova and Charles, 2007; Potapova et al., 2005). Other studies showed that diatom assemblages are sensitive to changes in salinity and to water movement (Busse and Snoeijs, 2002, 2003; Ulanova and Snoeijs, 2006). Planktonic and per- iphytic diatoms are included in many water quality monitoring pro- grammes worldwide (Kireta et al., 2012; El-Karim, 2014), and they are routinely utilized in freshwater systems, whereas applications to marine water are still limited (Cibic et al., 2012; B-Béres et al., 2016; Desrosiers et al., 2013). Diatom assemblages have been utilized also for the study of the effects of contamination by heavy metals, where this group showed also the presence of teratogenic forms in response to this kind of pollution (Rogelja et al., 2016; Siqueiros-Beltrones et al., 2014). Recent studies showed that the assemblage structure of benthic diatoms and other microscopic benthic components can be modified by altered environmental conditions and some taxa can be used as bio-indicator both at the level of genus and species (Desrosiers et al., 2013; Hill et al., 2001; Pusceddu et al., 2009). Diatoms represent also a significant component of the epilithon (flora adhering to hard substrates, and this definition is often utilized at http://dx.doi.org/10.1016/j.marpolbul.2017.08.001 Received 13 March 2017; Received in revised form 17 July 2017; Accepted 1 August 2017 ⁎ Corresponding author. E-mail address: c.pennesi@univpm.it (C. Pennesi). Marine Pollution Bulletin xxx (xxxx) xxx–xxx 0025-326X/ © 2017 Elsevier Ltd. All rights reserved. Please cite this article as: Pennesi, C., Marine Pollution Bulletin (2017), http://dx.doi.org/10.1016/j.marpolbul.2017.08.001