Invasion
Invasion Description
1st Record: Plymouth area, Devon/England/River Yealm, English Channel (Boalch and Potts 1977)
Geographic Extent
Devon/England/Salcombe Harbour (DeAmicis et al. 2015); Plymouth area, Devon/England/River Yealm, English Channel (1976, Boalch and Potts 1977; Crackington Cove, north Cornwall/England/Celtic Sea (1992, Eno et al. 1997; "most Irish coasts' (Minchin 2007); 15 west coast locations/Ireland/Atlantic Ocean (2001-2005, Guiry 2007); Kilmore Quay/Ireland/Celtic Sea (2001, Kraan 2009, 1st record for Ireland); Rath Strand/Ireland/Celtic Sea (2002, Kraan 2009); Galway County/Ireland/Cashel Bay (2002, Kraan 2009); Ireland/Lough Hyne, Celtic Sea (2003, Trowbridge et al. 2011; Letterard, Connemara/Ireland/Kikikieran Bay (2008, Baer and Stengel 2014); Salvaterra et al. 2013); Sligo County/Ireland/Drumcliff Bay (2002, Kraan 2009); Morvern/Scotland/Loch na Droma Buidhe (2007, Moore and Harries 2009, most northern UK location); Ireland/Atlantic Ocean (Peña et al. 2014, maerl beds)
Vectors
| Level | Vector |
|---|---|
| Alternate | Natural Dispersal |
| Alternate | Hull Fouling |
Regional Impacts
| Ecological Impact | Competition | |
| In experiments using assemblages of native algae and S. muticum reared in containers in the intertidal of Lough Hyne, Ireland, S. muticum had a negative impacts on the biomass of Fucus vesiculosus and, to a lesser extent, on Cladostephus spongiosus. In the Salcombe River estuary, England, S. muticum was able to attach to soft substrate within Eelgrass (Zostera marina) beds, because of the increased stability and decreased water movement (Tweedley et al. 2008). | ||
| Ecological Impact | Habitat Change | |
| In experiments in Lough Hyne, Ireland, benthic animal diversity and species richness was higher in assemblages of native algae than those containing S. muticum, probably because S. muticum contains less habitat cover (Salvaterra et al. 2013). On the West Coast of Ireland, S. muticum supports dense growths of the filamentous brown alga Pylaiella littoralis, especially in sheltered sites, where the epiphyte growth, inhibited photosynthesis, growth, and caused mortality. Growth of other epiphytes and survival of S. muticum was better in more exposed sites (Baer and Stengel 2014). In the Salcombe-Knightsbridge Estuary (English Channel), Devon, England, invasion by S. muticum resulted in shorter blade length of Eelgrass (Zostera marina), and altered epibiota communities. Although S. muticum provides a more structurally complex habitat, and supports larger abundances of some taxa, its seasonal die-offs may limit the establishment of populations (DeAmicis et al. 2015). | ||
| Ecological Impact | Herbivory | |
| Flat Periwinkles (Littorina obtusata and L. fabalis) from English Channel sites first colonized 6-40 years ago (1970s), fed as readily on S. muticum as on native Ascophyllum nodusum, in comparison to snails from later invaded areas. This could represent behavoral or evoultionary adaptation (Kurr and Davies 2018).
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