Invasion
Invasion Description
Portsmouth area/NH/Great Bay (2001, Ruiz et al. unpublished data)
Geographic Extent
Back Channel Marina, Portsmouth area/NH/Great Bay (2001, Ruiz et al., unpublished data); Badger Island Marina, Kittery/NH/Great Bay (2001, Ruiz et al. unpublished data); Main Marina Shipyard, Sounding Pier, Portsmouth area/ME/Great Bay (2001, Ruiz et al. unpublished data); Port Authority, Portsmouth area/NH/Great Bay (2001, Ruiz et al. unpublished data); Fort Point, Newcastle/NH/Great Bay (2002,USGS Woods Hole Science Center 2003-2007); Newington/NH/Piscataqua River (2002, USGS Woods Hole Science Center 2003-2007); Wentworth Marina, Portsmouth/HN/Great Bay (2006, Harris and Dijkstra 2008); Coastal Marine Lab, Portsmouth/NH/Great Bay (2003; MIT Sea Grant 2006; MIT Sea Grant 2009; 2006, Harris and Dijkstra 2008; 2010, Massachusetts Office of Coastal Zone Management 2013); Odiorne Point/NH/Gulf of Maine (2010, Massachusetts Office of Coastal Zone Management 2013); University of New Hampshire Coastal Marine Laboratory, Portsmouth/NH/Great Bay (2018, reeport Marina, Freeport/ME/Casco Bay (2018, Commonwealth of Massachusetts, Executive Office of Energy and Environmental Affairs, Office of Coastal Zone Management 2020); Port Harbor Marina, Portland/ME/Casco Bay (2018, Commonwealth of Massachusetts, Executive Office of Energy and Environmental Affairs, Office of Coastal Zone Management 2020)
Vectors
| Level | Vector |
|---|---|
| Probable | Hull Fouling |
Regional Impacts
| Ecological Impact | Competition | |
| In Portsmouth Harbor, by 2003-2006, colonial tunicates including D. vexillum replaced the mussel Mytilus edulis (1979-1982) as the dominant species in fouling communities (Dijkstra and Harris 2009). | ||
| Ecological Impact | Habitat Change | |
| In Portsmouth Harbor, by 2003-2006, colonial tunicates including D. vexillum replaced the mussel Mytilus edulis as the dominant species in fouling communities (Dijkstra and Harris 2009). A major functional change occured because while mussel shells provided structure, which other organisms can settle upon, colonial tunicates are more resistant to secondary settlement. However, colonial tunicates die off seasonally, creating large areas of bare substrate which can be colonized by other organisms (Dijkstra and Harris 2009). | ||