Invasion
Invasion Description
1st Record: Brunswick Nuclear Power Plant, Wilmington/NC/Cape Fear River Estuary (2000, Freshwater et al. 2006)
Geographic Extent
Cartaret County/NC/Bogue Sound (2003-2004, Freshwater et al. 2006); Brunswick Nuclear Power Plant, Wilmington/NC/Cape Fear River Estuary (2000, Thomas Thompson, presonal communication 2002; Freshwater et al. 2006);; New Hanover County/NC/Masonboro Sound (2000, Freshwater et al. 2006); NC/Myrtle Grove Sound (2001, Freshwater et al. 2006); SC/Charleston Harbor (2009, Byers et al. 2012, CH1- 32.7515, 79.9030; CH2- 32.7707, 79.9513; CH4- 32.7866, 79.8946); Seabrook Island/SC/Edisto River (Byers et al. 2012, site CH3, 32.3376 , 80.7885); Elliot's Beach, Parris Island/SC/Harbor River (2015, Krueger-Hadfield 2017, 32.4333, -80.6833); Hilton Head/SC/Port Royal Sound (Byers et al. 2012, 5 sites, 32.2227 , 80.7876 to 32.3376 ,, 80.7885); Priest’s Landing/GA/Savannah River (2013, Kollars et al. 2016, 31.96012° N, 81.01223°W); GA/Wassaw Sound (2009, Byers et al. 2012, 4 sites, 31.9260 , 80.9806 to 31.9633 , 81.0140 )
Vectors
| Level | Vector |
|---|---|
| Alternate | Fisheries Accidental (not Oyster) |
| Alternate | Ballast Water |
| Alternate | Hull Fouling |
Regional Impacts
| Economic Impact | Industry | |
| In 2000, a red alga, initially identified as A. aff. tenuistipauma, caused serious fouling in the Brunswick Nuclear Power Plant, on the Cape Fear River estuary, North Carolina (Thompson 2002, personal communication; Freshwater et al. 2006). | ||
| Ecological Impact | Habitat Change | |
| Agarophyton vermiculophyllum created extensive seaweed habitat in Charleston Harbor, Hilton Head, and the Savannah River Delta, by attaching the tubes of the polychaete Diopatra cuprea, providing habitat for invertebrate fauna, especially amphipods and snails (Byers et al. 2012). The seaweed provided habitat for very high densities of the amphipod Gammarus mucronatus in the Wilmington River and Wassaw Sound, Georgia. Little A. vermiculophyllum was consumed by the amphipods, but the seaweed provided a refuge from predators and from desiccation at low tide (Wright et al. 2014). Agarophyton vermiculophyllum enhanced the growth of Diopatra cuprea by attracting amphipods and other prey, who use the seaweeds for shelter (Kollars et al. 2016). Agarophyton vermiculophyllum also provides a predation refuge for the mud crab Panopeus herbstii, hiding from Blue Crabs (Callinectes sapidus), although this was intermediate in habitat value, compared to Eastern Oyster reefs (Bishop and Byers 2015). In mudflats in Georgia, the presence of G. vermiculophylla was associated with increased abundnace of benthic invertebrates, and shore birds, but bird responses were species-specific. In experimental setups on a smaller scale, most species preferred to forage in bare mud, or showed no preference (Haram et al. 2018). In an experiment, large areas (25 m2) of a mudflat were planted with high and low densities of G. vermiculophylla, and compared with control plots. Abundance and diversity of epifauna, sediment stabilization, attenuation of water flow, nursery functions, and a multifunctionality index, all showed a density-dependent relationship with G. vermiculophylla (Ramus et al. 2017). Ramus et al. (2017) argue that these positive relationships are beneficial, in relation to declining salt marsh and sea-grass habitats (Ramus et al. 2017). Two papers in 'Biological Invasions' debate Ramus et al.'s (2017) interpretation of the impacts of the impacts (Sotka et al. 2019; Thomsen et al. 2019). In particular, Sotka et al. dispute the depiction of southern intertidal mudflats as a degraded wasteland, and note that Agarophyton does not replace a lost foundational species, but is an introduced species with mixed impacts. | ||
| Ecological Impact | Food/Prey | |
| Gracilaria vermiculophylla created greatly increase seaweed biomass in Charleston Harbor, Hilton Head, and the Savannah River Delta, and rapidly decayed, providing a potential food source for invertebrates and microbes in the mudflats (Byers et al. 2012). | ||
| Ecological Impact | Trophic Cascade | |
The presence of Gracilaria vermiculophylla has had effects on the intensity of predation by carnivorous species on invertebrates in mudflats, bot by attracting prey, and also intering with some predators. Gracilaria vermiculophylla also provides a predation refuge for the mud crab Panopeus herbstii, hiding from Blue Crabs (Callinectes sapidus), although this was intermediate in habitat value, compared to Eastern Oyster reefs (Bishop and Byers 2015). In mudflats in Georgia, the presence of G. vermiculophylla was associated with increased abundnace of benthic invertebrates, and shore birds, but bird responses were species-specific. In experimental setups on a smaller scale, most species preferred to forage in bare mud, or showed no preference (Haram et al. 2018). | ||