Invasion
Invasion Description
1st Record: Denmark/Horsens Fjord (2003, Thomsen et al. 2007)
Geographic Extent
Denmark/Horsens Fjord (2003, Thomsen et al. 2007); Denmark/Vejle Fjord (2004, Thomsen et al. 2007); Horsens/Denmark/Inner Belt (Hammann et al. 2013, 55° 51’ 35.02’’ N, 9° 52’ 35.76’’E); Nyborg/Denmark/Outer Belt (Hammann et al. 2013, 55° 17’ 54.23’’ N, 10° 49’ 07.35’’E); Heiligenhafen/Germany/Belt Sea (Hammann et al. 2013; 54° 22’ 48.14’’ N, 10° 58’ 58.94’’E); Germany/Kiel Bay (2006, Thomsen et al. 2007); near Luttenberg/Germany/Kieil Bight (2007, Weinbeger et al. 2008)
Vectors
| Level | Vector |
|---|---|
| Alternate | Ballast Water |
| Alternate | Hull Fouling |
| Alternate | Oyster Accidental |
| Alternate | Canal |
Regional Impacts
| Ecological Impact | Food/Prey | |
| The snail Littorina littorea (Common Periwinkle, collected from the Kiel Fjord, Germany), consumed less of the invasive strains of G. vermiculophylla, from a German and a Danish site on the Belt Sea, compared to non-invasive strains from China. The invasive strains appear to have evolved traits for grazing resistance (Hammann et al. 2013). When G. vermiculophylla is grazed by the herbivore Idotea baltica, wounding of the plant causes a release of a range of chemical compunds, followed by an induced chemical defense (Nylund et al. 2011). | ||
| Ecological Impact | Competition | |
| In tank experiments, mats of Agarophyton vermiculophyllum can cover Eelgrass (Zostera marina) reducing its growth and survival (Martinez-Luscher and Holmer 2010). Field experiments on the Island of Fyn, Denmark, examine the effects of temperature and drifting populations of G. vermiculophylla on Eelgrass (Zostera marina). Overall, negative effects of high temperature (27°C) were most important, but a weak effect of algal cover was found at 27ºC when the Eelgrass was already stressed (Hoffle et al. 2011). | ||