Invasion
Invasion Description
1st Record: Patagonia/Argentina/Gulfo Nuevo (42 46.8 S; 64 59.46W) (Casas et al. 2004)
Geographic Extent
Puerto Madryn/Argentina/Atlantic Ocean (Schwindt et al. 2014; Schwindt et al. 2020); Patagonia/Argentina/Gulfo Nuevo (42 46.8 S; 64 59.46W) (1992, Casas et al. 2004); Patagonia/Argentina/Gulfo Nuevo (42 46.8 S; 64 59.46W) (Casas et al. 2004); Las Charas, Ambrosetti, Casino, Valdes Penisula/Argentina/San Jose and Nuevo Gulfs (2008, Raffo et al. 2014); Patagonia/Argentina/Cracker Bay (Raffo et al. 2009, 42 8560S, 64 8270W); Patagonia/Argentina/Rio Deseado (47 45 S; 65 55 W ) (2001, Martin and Cuevas 2006); Mar del Plata/Argentina/Mar del Plata Harbour (9/2011, Meretta et al. 2012, 38º02'00 S, 57º31'30 W); Puerto Madryn/Argentina/Gulfo Nuevo (Pereyra et al. 2014, PC; 41°41.689´S; 65° 01.412´W); Patagonia, Argentina/mouth of Salado stream, San Mattias Gulf (Pereyra et al. 2014, 41°36.877´S; 65°01.236´W);
Vectors
| Level | Vector |
|---|---|
| Alternate | Fisheries Accidental (not Oyster) |
| Alternate | Ballast Water |
Regional Impacts
| Ecological Impact | Competition | |
| In Gutto, Gulfo Nuevo, Patagonia, the invasion of U. pinnatifida decreased diversity of native seaweeds (Casas et al. 2004). However, Raffo et al. (2009) did not find evidence of competition between native Macrocystis pyrifera and U. pinnatifida, when examining growth and density of the two species in Cracker Bay, Patagonia. This could be due to examining an earlier phase of invasion, however (Raffo et al. 2009). Undaria pinnatifida in Patagonia frequently settles on Styela clava, and potentially could interfere with the growth of the tunicate. However, this has not been experimentally studied (Pereyra et al. 2017). | ||
| Ecological Impact | Habitat Change | |
| The diversity of fauna associated with the holdfast of U. pinnatifida was decreased, compared to that of the native kelp Macrocystis pyrifera, in Cracker Bay, Patagonia (Raffo et al. 2009). In reef areas off northern Patagonia, reefs with a low degree of relief, which were invaded by Undaria, had a low diversity of fishes compared to similar uninvaded reefs. Reefs with higher relief were not noticeably affected by the Undaria invasion, because Undaria tended to colonize only the lower portions of the reefs, leaving many refuge areas unaltered (Irigoyen et al. 2011a). Experimental plots covered by Undaria had higher algal biodiversity, and abundance of several invertebrates than sites from which Undaria was removed (Irigoyen et al. 2011b). Exudates of Undaria affect the optical properties of seawater and stimulate microbia growth (Lozada et al. 2021). | ||
| Ecological Impact | Food/Prey | |
| In Puerto Madryn, Patagonia, experimental studies found that the sea urchins Arbacia dufresnii and Pseudechinus magellanicus grazed lightly on Undaria pinnatifida, while the gastropod Tegula patagonica fed on the kelp's epibiota. However, P. magellanicus was not seen feeding on this kelp in the field (Teso et al. 2009). | ||