The value of regular monitoring and diverse sampling techniques to assess aquatic non-native species: a case study from Orkney Author Kakkonen, Jenni E. * & Marine Services, Harbour Authority Building, Scapa, Orkney, KW 15 1 SD, United Kingdom Author Worsfold, Tim M. APEM Ltd., Diamond Centre, Works Road, Letchworth Garden City, SG 6 1 LW, United Kingdom Author Ashelby, Christopher W. APEM Ltd., Diamond Centre, Works Road, Letchworth Garden City, SG 6 1 LW, United Kingdom Author Taylor, Andrea * & Marine Services, Harbour Authority Building, Scapa, Orkney, KW 15 1 SD, United Kingdom Author Beaton, Katy * & Marine Services, Harbour Authority Building, Scapa, Orkney, KW 15 1 SD, United Kingdom text Management of Biological Invasions 2019 2018-10-17 10 1 46 79 http://dx.doi.org/10.3391/mbi.2019.10.1.04 journal article 299406 10.3391/mbi.2019.10.1.04 a53d05d0-2083-4f05-a83c-8f418fdc5468 1989-8649 11969078 (6) Codium fragile ssp. fragile (Suringar) Hariot, 1889 Status in U.K. – non-native. Codium fragile ssp. fragile (“green fingers”) has been recorded each year of the monitoring programme since 2014, mainly from rapid assessment samples but also from a scrape sample in 2017. It has been found throughout Scapa Flow and at two sites outside Scapa Flow. Wilkinson (1975) previously reported the subspecies (as C. f. ssp. tomentosoides (van Goor) Silva, 1955 ) from Orkney at Burray Ness on the east coast of Burray and it was reported from renewable energy structures in Orkney by Want et al. (2017) but according to Provan et al. (2008) it has been present in Orkney since at least 1891. It is otherwise widespread and well established throughout the U.K. ( Minchin et al. 2013 ).