Invasion
Invasion Description
1st Record: Boothbay Harbor/ME/Boothbay Harbor (on transplanted oysters, 1964, Carlton and Scanlon 1985);
Geographic Extent
Provincetown/MA/Cape Cod Bay (1980, Carlton and Scanlon 1985); Wellfleet/MA/Cape Cod Bay(1974, Carlton and Scanlon 1985); Brewster/Cape Cod Bay (1974, Carlton and Scanlon 1985); Barnstable/MA/Cape Cod Bay (1972, Carlton and Scanlon 1985); Sandwich/MA/Cape Cod Canal; Plymouth/MA/Cape Cod Bay (1974, Carlton and Scanlon 1985); Brewers Plymouth Marina/Plymouth Harbor, Cape Cod Bay (2010, Massachusetts Office of Coastal Zone Management 2013); Duxbury/MA/Cape Cod Bay Duxbury Bay (Cape Cod Bay) (1981, Carlton and Scanlon 1985); Hawthorne Marina, Salem/MA/Salem Harbor (2000, MIT Sea Grant 2003; 2010, Massachusetts Office of Coastal Zone Management 2013); Isles of Shoals/NH-ME/Gulf of Maine (1983, Carlton and Scanlon 1985); Rye Ledge/NH/Gulf of Maine (1985, Mathieson et al. 2003); Weeks Point/NH/Great Bay 1985, Mathieson et al. 2003); Cape Neddick/York/ME/Gulf of Maine (1989, Mathieson et al. 2003); Kittery/ME/Brave Boat Harbor Marsh (1999, Mathieson et al. 2001; Benton et al. 2015); Cape Elizabeth/ME/Dyers Cove, Casco Bay (2010, Massachusetts Office of Coastal Zone Management 2013); Wilbur's Neck, Wharton Point/ME/Maquoit Bay (Casco Bay) (1995, Mathieson et al. 2001) ; Harpswell, Bailey Island/ME/Casco Bay (1994, Mathieson et al. 2001);; Reid State Park, Georgetown/ME/Sheepscot River (1994, Mathieson et al. 2001);Boothbay Harbor/ME/Boothbay Harbor (on transplanted oysters, 1964, Carlton and Scanlon 1985); Rachel Carson Salt Pond Preserve, Bristol/ME/Muscongus Bay, (1995, Mathieson et al. 2001); Bar Harbor/ME/Frenchman's Bay (late 70s, early 1980s, Bird et al. 1993); Wilbur Neck, Eastport/ME/Cobscook Bay (2006, Matheison et al. 2009, 'found in drift'); Saint Patricks Parish/New Brunswick/Sam Orr's Pond, Passamaquoddy Bay (10/14/09, Saunders et al. 2013); Yarmouth/Nova Scotia/Gulf of Maine (2008. Choi et al. 2016)
Vectors
| Level | Vector |
|---|---|
| Alternate | Oyster Accidental |
| Alternate | Canal |
| Alternate | Hull Fouling |
| Probable | Ballast Water |
| Alternate | Natural Dispersal |
Regional Impacts
| Ecological Impact | Competition | |
| Codium fragile invades kelp beds after disturbances, and displaces kelps, and inhibits kelp recruitment. It exploits the fouling and killing of kelps by the introduced bryozoan Membranipora membranacea (Levin et al. 2002). In shallow waters along the Isle of Shoals, there was a gradual shift from kelps to Codium and to an opportunistic red alga community (Harris and Tyrell 2001). | ||
| Ecological Impact | Habitat Change | |
| Codium fragile replaces kelp canopy with less favorable habitat, and supports fewer juvenile fishes (Cunner, Tautogolabrus adspersus) (Levin et al. 2002). Around the Isles of Shoals, NH-ME, from the 1979 to 2015, there has been a trend of replacement of kelps and other larger brown seaweeds, by smaller, bushier red seaweeds (Bonnemaisonia hamifera, Dasysiphonia japonica, and Neosiphonia spp.) and Codium fragile, increasing the structural complexity of the environment, and the abundance and diversity of meso-sized invertebrates (Dijkstra et al. 2017). | ||
| Ecological Impact | Food/Prey | |
| The native snail Lacuna vincta occurred in lower density on Codium fragile than on the native kelp Laminaria saccharina. In experiments, feeding and growth was reduced in L. vincta on Codium, compared to Laminaria (Chavanich and Harris 2004). The herbivorous saccoglossan sea-slug Pacifia dendritica feeds on C. fragile, and can control the seaweed's populations (Harris and Adams 2005). This sea slug may have been present, but rare on the East Coast, before the Codium invasion (Bleakney 1989). | ||