Non-native species

Non-native seaweed species

Currently, there are 10 non-native seaweed species recorded from Lundy plus two sub-species. These are listed in the table below. The arrival of a non-native species of kelp, wakame Undaria pinnatifida, is expected; it originates from the NW Pacific and was first recorded in the UK in the Hamble estuary in the Solent. It now occurs at locations all along the English Channel coast. If it does appear, it is likely to be found beneath the jetty first – please keep an eye out for it!

Table listing the non-native seaweed species recorded from Lundy to date.

Common name	Scientific name	Authority	Notes	Photograph
Green sponge fingers (subspecies)	Codium fragile subsp. atlanticum	(A.D.Cotton) P.C.Silva, 1955	First recorded at Lundy in 2008.	Photo not yet available
Green sponge fingers (subspecies)	Codium fragile subsp. fragile	(Suringar) Hariot, 1889	First recorded at Lundy in 2022.	Photo not yet available
A red alga	Antithamnionella ternifolia	(Hooker F. & Harvey) Lyle, 1922	Invasive. Native of SW South America.	Photo not yet available
Harpoon weed	Asparagopsis armata	Harvey, 1855	First found at Lundy in 1949 as Falkenbergia stage (Harvey & Drew, 1949) which, in 2022, was reported as being abundant by the jetty (Hiscock 2022). The ‘harpoon-like’ gametophyte stage first encountered at Lundy in 1973, though rarely seen until latter part of 2000s.
Hook weed	Bonnemaisonia hamifera	Hariot, 1891	Native to NW Pacific. Tetrasporophyte stage originally known as Trailliella. First recorded on kelp stipes by Irvine et al. (1972) and again in 2022.
Pom-pom weed	Caulocanthus okamurae	Yamada, 1933	Native to the NW Pacific. Recorded from Lundy for the first time at Devil’s Kitchen in 2021, at Gannets’ Bay in 2022, though not found in Devil’s Kitchen or at Quarry Beach in 2024.
Siphoned Japan weed	Dasysiphonia japonica	(Yendo) H.S.Kim, 2012	Native to western Pacific. Recorded from Lundy for first time at Brazen Ward in 2022.
Devil’s tongue weed	Grateloupia turuturu	Yamada, 1941	Native to NW Pacific. First recorded at Lundy in 2008. Not seen in intertidal searches in 2024.
Harvey’s siphon weed	Melanothamnus harveyi	(Bailey) Díaz-Tapia & Maggs, 2017	Native to NW Atlantic. Recorded from Lundy for the first time in 2022.
Pale patch laver	Pyropia leucosticta	(Thuret) Neefus & J.Brodie, 2011	Formerly known as Porphyra leucosticta. First recorded at Lundy during the late 1940s.	Photo not yet available
Oyster thief	Colpomenia peregrina	Sauvageau, 1927	Native to NE Pacific.
Wireweed	Sargassum muticum	(Yendo) Fensholt, 1955	Native to NW Pacific. First recorded at Lundy in 1999 (Reach, 2003). Thought to have been introduced accidentally attached to a jack-up rig brought to build the jetty.

Non-native invertebrate species

To date there are only three non-native invertebrate species which have made their way to Lundy (listed in the table below) although one of these, the Pacific oyster Magallana gigas, has not been recorded again since 2021. The red ripple bryozoan Watersipora subatra was first seen attached to the wall of a small cave on the north side of Rat Island in May 2021 and has since spread: it now (2024) covers extensive areas of overhanging and vertical shaded rock surfaces on the NW side of Rat Island. The extent of its colonies will continue to be monitored.

Some non-native species can be tolerated and no ‘active management’ is required to keep them in check. This happens when the species in question has little impact on the habitat in which it is found. Others, such as the Pacific oyster, can multiply rapidly if conditions for settlement are favourable, causing a complete change of the habitat which existed before their arrival. This situation has occurred in certain sheltered estuaries in south Devon. The five individual oysters found in 2021 were destroyed using a hammer, after this action was agreed following discussions between the Warden and Dr Keith Hiscock, aired during a meeting of the MPA Advisory Group.

One non-native species which may appear at Lundy in the future (though it is hoped it won’t!) is the slipper limpet Crepidula fornicata. This gastropod, which forms ‘stacks’ of individuals attached to each other, is native to the eastern seaboard of North America and was first introduced to Essex in consignments of American oysters Crassostrea virginica between 1887-1890. It has since spread throughout the English Channel and as far north as Spurn Head on the east coast and to Milford Haven and Cardigan Bay on the west coast. It has been recorded on/off the English mainland coast and on whelk pots in the outer Bristol Channel. It can rapidly colonise intertidal and subtidal areas of muddy gravel, particularly where these are mixed with shell, so the seabed adjacent to Lundy’s east coast would seem ideal habitat for it to colonise. Unfortunately, it has the ability to change the seabed habitat where it is found, partly through their rapid and dense colonisation of areas and partly through the production of ‘pseudofaeces’ which has the effect of smothering other bivalves. Even though the east side of Lundy is relatively sheltered, it is hoped the exposure it occasionally experiences will be sufficient to prevent slipper limpet larvae from settling here.

Table listing the non-native invertebrate species recorded from Lundy to date.

Common name	Scientific name	Authority	Notes	Photograph
Red ripple bryozoan	Watersipora subatra	(Ortmann, 1890)	Native to western Pacific. First recorded at Lundy in 2021.
Modest barnacle	Austrominius modestus	(Darwin, 1854)	Originally recorded at Lundy as Elminius modestus in 1978. An Australasian species first recorded in Britain in 1946. In the photo to the right, Elminius modestus is the uppermost, slightly larger barnacle; the others are stellate barnacles Chthalamus montagui.
Pacific oyster	Magallana gigas	(Thunberg, 1793)	First recorded as 5 individuals in the vicinity of the jetty in 2021. These were subsequently destroyed. Not seen since.

The arrival of non-native species to Lundy’s shores and seabed may occur at any time, so anyone who might think they have come across an unfamiliar species is asked to mention it to the Warden (hopefully with a photo!), who will be able to investigate the matter further; alternatively, please enter your information on the uploadable Sightings Recording form here.