water Article Floating Wetland Islands Implementation and Biodiversity Assessment in a Port Marina 1, , 1,2, 1 1,2 Cristina S. C. Calheiros * y , João Carecho y, Maria P. Tomasino , C. Marisa R. Almeida and Ana P. Mucha 1,2 1 Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Novo Edifício do Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, S/N, 4450-208 Matosinhos, Portugal;
[email protected] (J.C.);
[email protected] (M.P.T.);
[email protected] (C.M.R.A.);
[email protected] (A.P.M.) 2 Faculty of Sciences, University of Porto, Praça de Gomes Teixeira, 4099-002 Porto, Portugal * Correspondence:
[email protected] These authors contributed equally to this manuscript. y Received: 27 October 2020; Accepted: 18 November 2020; Published: 21 November 2020 Abstract: Floating wetland islands (FWI) are considered nature-based solutions with great potential to promote several ecosystem services, such as biodiversity and water quality enhancement through phytoremediation processes. To our knowledge, the present work is the first to scientifically document the in-situ establishment of an FWI in a seawater port marina. The establishment and performance of a cork floating platform with a polyculture (Sarcocornia perennis, Juncus maritimus, Phragmites australis, Halimione portulacoides, Spartina maritima, Limonium vulgare) was evaluated. The diversity of organisms present in the FWI was undertaken based on the macrofauna assessment, taking into consideration marine water characterization, with a focus on hydrocarbons. Microbial communities were assessed based on metabarcoding approach to study 16S rRNA gene from environmental DNA retrieved from biofilm (from the planting media), marine biofouling (from the submerged platform) and surface marina water.