Invasion
Invasion Description
1st Record: White Horse Beach, Plymouth/MA/Cape Cod Bay (4/12/10, Savoie and Saunders 2013)
Geographic Extent
Fort Williams State Park, Cape Elizabeth/ME/Casco Bay (2012, Newton et al. 2013); Two Lights State Park, Cape Elizabeth/ME/Casco Bay (2012, Newton et al. 2013); Cape Elizabeth/ME/Kettle Cove, Gulf of Maine (2012, Newton et al. 2013); University of New Hampshire Coastal Research Laboratory, Newcastle/NH/Great Bay (2013, Wells et al. 2014; Mathieson 2016); Appledore Island/ME/Gulf of Maine (2011, Science Daily 9/13/2012); Rye Beach/NH/Gulf of Maine (2012, Newton et al. 2013, drifitng); Back Beach, Rockport/MA/Gulf of Maine (2012, Newton et al. 2013); Folly Cove, Gloucester/MA/Gulf of Maine (Savoie and Saunders 2013); Niles Beach, Gloucester/MA/Massachusetts Bay (4/19/12, Savoie and Sunders 2013); Good Harbor Beach, Gloucester/MA/Massachusetts Bay (2012, Newton et al. 2013); north to Cape Ann/MA/Gulf of Maine (2011, James T. Carlton, email to Paul Fofonoff); Singing Beach, Manchester/MA/Massachusetts Bay (2012, Newton et al. 2013); West Beach, Beverly/MA/Massachusetts Bay (2012, Newton et al. 2013);Canoe Beach, Nahant/MA/Massachusetts Bay (2010, Ramsay-Newton et al. 2016, 4225012.600N, 7054021.300W) ; Pea Island, Nahant/MA/Massachusetts Bay (2012, Newton et al. 2013); White Horse Beach, Plymouth/MA/Cape Cod Bay (4/12/10, Savoie and Saunders 2013); Sandwich Town Beach, Sandwich/MA/4/14/10, Savoie and Saunders 2013); Corporation Beach, Dennis/MA/Cape Cod Bay (4/13/11, Savoie and Saunders 2013)
Vectors
Level | Vector |
---|---|
Alternate | Hull Fouling |
Alternate | Ballast Water |
Alternate | Natural Dispersal |
Regional Impacts
Ecological Impact | Competition | |
In the Gulf of Maine, where D. japonica was first discovered in 2010, by 2012 it has become the second most abundant macroalga in subtidal communities, comprising on average 17% of the community. At some locations, it had 100% coverage. Species richness was negatively correlated with H. japonica abundance (Newton et al. 2013). At Nahant MA, on Massachusetts Bay, Heterosiphonia japonica was dominant in areas with reduced native diversity, had higher rates of nitrate uptake, grew faster than other dominants, and had reduced grazing from a common herbivore, the native snail Lacuna vincta (Chink Shell). These differences were context-dependent; growth rates of the species did not differ in isolation in the laboratory (Low et al. 2014). However, the aggressiveness and nutrient uptake of D. japonica decreased in the 5 years since the initial invasion. The biodiversity of the community continued to be reduced after the invasion (Ramsay-Newton et al. 2016). | ||
Ecological Impact | Habitat Change | |
Around the Isles of Shoals, NH-ME, from the 1979 to 2015, kelps and other larger brown seaweeds were becoming replaced 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). A mid-sized predatory fish, the Cunner (Tautogolabrus adpsersus) preferred kelps to the shorter, bushier seaweeds, dominated by D. japonica in experiments, but the type of seaweed community did not affect the fish's predation success on invertebrates (O'Brien et al. 2018). | ||