*2.1. Study Area*

The transplants of aquatic angiosperms took place in an area measuring approximately 36.6 km<sup>2</sup> (Figure 1) situated in the northern basin of the Venice Lagoon (sexagesimal coordinates: 45◦30–34 N, 12◦27–33 E).

**Figure 1.** Map of the sampling area with the 35 transplanting stations. In red and white, the 17 stations transplanted in spring 2014. The stations in red were monitored monthly for one year for environmental parameters. In yellow, the 18 stations transplanted in spring 2015.

Thirty-five stations characterized by shallow waters were identified in the study area, along the edges of the salt marshes and lagoon canals. The transplanting area is naturally divided by a deep canal (San Felice) which flows in a south-northern direction. On the east side of the lagoon, bottoms are shallower, there is no source of freshwater, and the trophic status is low. On the contrary, the trophic status of the west side is quite high due to the waters of some branches of the Silone river (flow 5 m<sup>3</sup> s<sup>−</sup>1) and the Sile river overflows in rainy periods (flow rates: from a few m<sup>3</sup> s<sup>−</sup><sup>1</sup> to 70 m<sup>3</sup> s<sup>−</sup>1), which have an average frequency of 8–9 events per year [14]). The waters, rich in nutrients and suspended particulate, favor the growth of tionitrophilic algae and trigger phytoplankton blooms that hamper plant rooting.
