This dataset contains records from Heiser et al (2014) Assessing the extent of establishment of Undaria pinnatifida in Plymouth Sound Special Area of Conservation, UK Marine Biodiversity Records, page 1 of 8 doi:10.1017/S1755267214000608; Vol. 7; e93. The first UK record of Undaria pinnatifida was in the Hamble estuary (1994) and it was found off Plymouth in 2003. The authors assessed the distribution of U. pinnatifida and native kelps and their allies in Plymouth Sound (at 0 to +1 m relative to Chart Datum). Undaria pinnatifida was widespread along rocky shores, on other hard substrata and grew in the same areas as Saccharina latissima and Saccorhiza polyschides. Undaria pinnatifida was significantly more abundant on vertical substrata than on upward-facing hard substrata. It was almost as common as all of the other kelp species combined on vertical substrata but was outnumbered by native species on upward-facing substrata. Undaria pinnatifida has become the visually dominant macroalga in marinas and has spread to surrounding natural habitats in Plymouth Sound. The extent to which it will out-compete native kelps requires monitoring, especially in conservation areas.
