Invasion
Invasion Description
1st record: Isles of Shoals/ME-NH/Gulf of Maine (1987, Berman et al. 1993; Harris and Tyrell 2000, on blades of kelp, Saccharina latissima = Laminaria saccharum spp.)
Geographic Extent
Isles of Shoals/ME-NH/Gulf of Maine (1987, Berman et al. 1993; Harris and Tyrell 2000, on blades of kelp, Saccharina latissima = Laminaria saccharum)
Vectors
| Level | Vector |
|---|---|
| Alternate | Hull Fouling |
| Alternate | Ballast Water |
Regional Impacts
| Ecological Impact | Competition | |
| In the Isles of Shoals (NH-ME), Membranipora membranacea's colonies overgrew large areas of the fronds of kelp (Laminaria saccharina = Saccharina latissima), potentially decreasing the photosynthesis and growth of the seaweed. In addition, M. membranacea consistently overgrows the bryozoan Electra pilosa and the hydroid Obelia geniculata on kelp fronds, and is rarely overgrown by other epiphytes (Berman et al. 1992). Over time, from 1996-1999, in the Isles of Shoals, M. membranacea increasingly colonized other algal species, Agarum clathratum, Desmarestia aculeata, and the introduced Codium fragile (Harris and Tyrell 2001). | ||
| Ecological Impact | Habitat Change | |
| Kelps overgrown by M. membranacea are more vulnerable to breaking and tearing during storm surges (Berman et al. 1992). Decreases in the abundance of large kelps (Saccharina = Laminaria spp.) at the Isles of Shoals have contributed to increases in other seaweeds (Agarum clathratum, Desmarestia aculeata, and the introduced Codium fragile fagile, which suffer less damage from colonization by M. membranipora (Harris and Tyrell 2001). | ||