Species alert
12 new marine species found in the Dutch Wadden Sea
In 2009, the Dutch Invasive Alien Species Team requested a survey (rapid
assessment) of (alien) marine algae and macrofauna of hard substrata in the
Dutch Wadden Sea. During this survey 83 localities were searched for native
and non-native species. In total 129 species were observed, 29 of which were
cryptogenic or of non-native origin. Twelve of these species and one
subspecies were found to be new to the Dutch Wadden Sea. One red alga (Ceramiaceae
sp.) is probably a new species to Europe. The sea-squirt Molgula socialis is
recorded as new for the Netherlands. It is probably widespread, may even be
native and misidentified in the past as the non-native American species M.
manhattensis.
The total number of non-native species in the Dutch Wadden Sea has been
raised to 64. The observed (sub)species of an alien or unknown origin in
the survey are:
- Antithamnionella spirographidis (Schiffner) Wollaston, 1968
- Ceramium cimbricum H.E. Petersen, 1924
- An unknown Ceramiaceae species,
- Codium fragile ssp. atlanticum (A.D.Cotton) P.C. Silva, 1955
- Gracilaria vermiculophylla (Ohmi) Papenfuss, 1967,
- Ficopomatus enigmaticus (Fauvel, 1923)
- cf Neodexiospira brasiliensis (Grube, 1872)
- Aplidium glabrum (Verrill, 1871)
- Botrylloides violaceus Oka, 1927
- Didemnum vexillum Kott 2002
- Molgula socialis Alder, 1863
- Caprella mutica Schurin, 1935
- Jassa marmorata (Holmes, 1903)
All results from this survey can be downloaded
here. The
new website from the Invasive Alien Species Team (in the Dutch language) is
online.
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