Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979 (additional source)
Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968 (additional source)
Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922 (additional source)
Bonnemaisonia hamifera Hariot, 1891 (additional source)
Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955 (additional source)
Colpomenia peregrina Sauvageau, 1927 (additional source)
Grateloupia doryphora (Montagne) M.Howe, 1914 (additional source)
Pikea californica Harvey, 1853 (additional source)
Solieria chordalis (C.Agardh) J.Agardh, 1842 (additional source)
Undaria pinnatifida (Harvey) Suringar, 1873 (additional source)

Atlantic Coast of Spain for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Atlantic Coast of Spain for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
Azores Exclusive Economic Zone for Bonnemaisonia hamifera Hariot, 1891  (origin: alien)
Belgian Exclusive Economic Zone for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
British Isles for Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979  (origin: alien)
British Isles for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922  (origin: alien)
British Isles for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922  (origin: alien)
British Isles for Asparagopsis armata Harvey, 1855  (origin: alien)
British Isles for Bonnemaisonia hamifera Hariot, 1891  (origin: alien)
British Isles for Colpomenia peregrina Sauvageau, 1927  (origin: alien)
British Isles for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
Brittany for Grateloupia doryphora (Montagne) M.Howe, 1914  (origin: alien)
Brittany for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
Cornwall for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Cornwall for Solieria chordalis (C.Agardh) J.Agardh, 1842  (origin: alien)
Danish Exclusive Economic Zone for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Dorset for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
Dorset for Grateloupia doryphora (Montagne) M.Howe, 1914  (origin: alien)
Dorset for Solieria chordalis (C.Agardh) J.Agardh, 1842  (origin: alien)
Dutch Exclusive Economic Zone for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922  (origin: alien)
East Coast of England for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
East Scotland for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
England for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
England for Grateloupia doryphora (Montagne) M.Howe, 1914  (origin: alien)
English Channel for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
French part of the English Channel for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
French part of the Mediterranean Sea - Western Basin for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
Irish Exclusive economic Zone for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
Irish Exclusive economic Zone for Bonnemaisonia hamifera Hariot, 1891  (origin: alien)
Isle of Wight for Grateloupia doryphora (Montagne) M.Howe, 1914  (origin: alien)
Jersey for Grateloupia doryphora (Montagne) M.Howe, 1914  (origin: alien)
Jersey part of the English Channel for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
Langstone Harbour for Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979  (origin: alien)
Mediterranean Sea for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
Mediterranean Sea for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Netherlands Antilles for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
North France for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
North Sea for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Northumberland for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
Norwegian Exclusive Economic Zone for Bonnemaisonia hamifera Hariot, 1891  (origin: alien)
Norwegian Exclusive Economic Zone for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
Portuguese Atlantic Coast for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Portuguese Exclusive Economic Zone for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922  (origin: alien)
Portuguese Exclusive Economic Zone for Grateloupia doryphora (Montagne) M.Howe, 1914  (origin: alien)
Scilly Isles for Pikea californica Harvey, 1853  (origin: alien)
Scilly Isles for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Shetlands for Asparagopsis armata Harvey, 1855  (origin: alien)
Shetlands for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
South Coast of England for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
South Norway for Colpomenia peregrina Sauvageau, 1927  (origin: alien)
South Norway for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
South Wales for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
South Wales for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Spain for Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979  (origin: alien)
Spain for Asparagopsis armata Harvey, 1855  (origin: alien)
Spain for Solieria chordalis (C.Agardh) J.Agardh, 1842  (origin: alien)
Strangford Lough for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Swedish Exclusive Economic Zone for Sargassum muticum (Yendo) Fensholt, 1955  (origin: alien)
Torquay for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
United Kingdom part of the English Channel for Undaria pinnatifida (Harvey) Suringar, 1873  (origin: alien)
United Kingdom part of the Inner Seas off the West Coast of Scotland for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922  (origin: alien)
Wales for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
Wales for Solieria chordalis (C.Agardh) J.Agardh, 1842  (origin: alien)
West Coast of England for Codium fragile subsp. atlanticum (A.D.Cotton) P.C.Silva, 1955  (origin: alien)
West Coast of Scotland for Antithamnionella spirographidis (Schiffner) E.M.Wollaston, 1968  (origin: alien)
West Mediterranean for Asparagopsis armata Harvey, 1855  (origin: alien)
West Mediterranean for Solieria chordalis (C.Agardh) J.Agardh, 1842  (origin: alien)

English common cord-grass [from synonym] for Spartina townsendii var. anglica (C.E. Hubbard)

 Distribution

 for Agardhiella subulata (C.Agardh) Kraft & M.J.Wynne, 1979

Still sporadic in occurrence, but mainly localised to Langstone and Chichester harbours. West Sussex [details]

 distribution

 for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922

European populations from the Netherlands south as far as Portugal [details]

 distribution

 for Asparagopsis armata Harvey, 1855

European populations can be found from the western Mediterranean to Shetland [details]

 distribution

 for Bonnemaisonia hamifera Hariot, 1891

In Europe it is found from Norway to the Azores including Ireland [details]

 Distribution

 for Codium fragile subsp. tomentosoides (van Goor) P.C.Silva, 1955

From Atlantic Spain to Norway. [details]

 Distribution

 for Colpomenia peregrina Sauvageau, 1927

In europe it is found from Iberia to southern Norway. [details]

 Distribution

 for Haliplanella lineata (Verrill, 1869)

Generally occurring in estuaries, ports and harbours on major shipping routes [details]

 Distribution

 for Pleurosigma simonsenii Hasle, 1990

It has been sporadically reported in the English Channel an southern North Sea, but it may have more or less ... [details]

 Distribution

 for Polysiphonia harveyi Bailey, 1848

European populations occur from Norway to the Mediterranean, including Ireland [details]

 Distribution

 for 

The Norfolk population appears to be no longer extant. [details]

 distribution

 for Thalassiosira tealata Takano, 1980

from the English Channel to Norway [details]

 Introduced species vector dispersal

 for Antithamnionella ternifolia (Hooker f. & Harvey) Lyle, 1922

in Belgian part of the North Sea: Ships: accidental as attached or free-living fouling organisms [details]

 Introduced species vector dispersal

 for Austrominius modestus (Darwin, 1854)

in Belgian part of the North Sea: Ships: accidental with ballast water, sea water systems, live wells or other deck ... [details]

 Introduced species vector dispersal

 for Austrominius modestus (Darwin, 1854)

in Belgian part of the North Sea: Ships: accidental as attached or free-living fouling organisms [details]

 Introduced species vector dispersal

 for Crepidula fornicata (Linnaeus, 1758)

in Belgian part of the North Sea: Ships: accidental with ballast water, sea water systems, live wells or other deck ... [details]

 Introduced species vector dispersal

 for Crepidula fornicata (Linnaeus, 1758)

in Belgian part of the North Sea: Aquaculture: accidental [details]

 Introduced species vector dispersal

 for Ficopomatus enigmaticus (Fauvel, 1923)

in Belgian part of the North Sea: Aquaculture: accidental [details]

 Introduced species vector dispersal

 for Neosiphonia harveyi (Bailey) M.-S.Kim, H.-G.Choi, Guiry & G.W.Saunders, 2001

in Belgian part of the North Sea: Aquaculture: accidental [details]

 Introduced species vector dispersal

 for Spartina townsendii var. anglica (C.E. Hubbard)

in Belgian part of the North Sea: Other [details]

 Introduced species vector dispersal

 for Spartina townsendii var. anglica (C.E. Hubbard)

in Belgian part of the North Sea: Ships: accidental with ballast water, sea water systems, live wells or other deck ... [details]

 Introduced species vector dispersal

 for Styela clava Herdman, 1881

in Belgian part of the North Sea: Ships: accidental as attached or free-living fouling organisms [details]

 Introduced species vector dispersal

 for Thalassiosira punctigera (Castracane) Hasle, 1983

in Belgian part of the North Sea: Ships: accidental with ballast water, sea water systems, live wells or other deck ... [details]

 Introduced species vector dispersal

 for Undaria pinnatifida (Harvey) Suringar, 1873

in Belgian part of the North Sea: Aquaculture: accidental [details]