1st Record: Italy/Lagoon of Venice (Adriatic Sea) (1992, Curiel et al. 1998; Curiel et al. 2001; Occhipinti Ambrogi 2000)

Italy/Lagoon of Venice (Adriatic Sea) (Curiel et al. 1998; Curiel et al. 2001; Occhipinti Ambrogi 2000; Petrocelli et al. 2019)

Ecological Impact		Competition
The invasion of Undaria pinnatifida in the Venice Lagoon is believed to have decreased diversity and abundance of native understory seaweeds, through competition for substrate (Curiel et al. 1998)

Economic Impact		Aesthetic
In eutrophic portions of the Venice Lagoon, Undaria pinnatifida forms large floating masses (Sfriso and Facca 2013). A photograph on the AlgaeBase website, shows large masses surrounding moored gondolas, probably unattractive to tourists (Guiry and Guiry 2016). Experimental mechanical removal of Undaria pinnatifida from plots in the Venice Lagoon was more effective in July, after the reproductive period, than in March, when the seaweeds were fertile. The July removal allowed other algae to colonize the cleared area and delayed recolonization for about 2 years. However, the experiment showed that effective eradication would have to be done at a very large scale (Curiel et al. 2001).

Economic Impact		Shipping/Boating
Undaria pinnatifida in the Venice Lagoon interferes with navigation of small boats (Sfrizo and Facca 2013).

Species Regional Summary Undaria pinnatifida None ( MED-VII )