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Nieuw-Zeelandse zeepok Austrominius modestus

Foto: Stefan Verheyen


Balanidae [familie]
Austrominius [genus] (1/1)
modestus [soort]

Exotenpaspoort ?

Reële kans op vestiging? Ja
Betrouwbaarheid beoordeling Grote mate van zekerheid (meerdere bronnen)
Vestigingsstatus Gevestigd
Zeldzaamheid Zeer algemeen
Invasiviteit Invasief
Invasiviteit (toelichting) A. modestus is native to New Zealand and southern Australia (Harms 1999). It was Introduced into Europe in 1940-1943 on ships’ hulls (Bishop 1947, Stubbings 1950) and dispersed further in Europe by hull fouling and marine currents (Crisp 1958). Its invasiveness is extremely large. It has the ability to live in a relatively wide range of habitats from -3-4 m to high in the intertidal. It can become very abundant in a very short time. It grows very fast and has a very high fecundity (Crisp & Davies 1955). The species is hermaphroditic (but requires cross-fertilization). It produces broods throughout the year, releasing each brood within two weeks (Barnes & Barnes 1968). It tolerates lower salinity and higher temperatures than most native barnacles, except the other introduced species, Balanus improvisus (Gittenberger et al. 2010).
Type introductie Niet opzettelijk
Jaar van eerste introductie 1946
Jaar van eerste melding 1948
Natuurlijke verspreiding Zuidelijke Stille Oceaan
Verspreiding in Nederland
  • Friesland
  • Groningen
  • Noord-Holland
  • Zuid-Holland
  • Zeeland
  • Verspreiding in Nederland (toelichting) E. modestus was first found in the Netherlands in 1946 (Boschma 1948, Leenhouts 1948). It spread extremely fast through the Dutch coastal waters and along the North Sea coast (Stock 1949) en has colonized the entire coast, including the Wadden Sea, at 1951 (Wolff 2005). There it is now the most abundant barnacle by far, inhabiting a wide range of littoral and sublittoral habitats (Gittenberger et al. 2010). This is also the case at many localities in the province of Zeeland (Vaas 1975). It is nowadays a very common species in the Netherlands, to be found almost everywhere, except in deeper offshore localities.
  • Mariene habitats
  • Estuaria en brakwatergebieden
  • Kustgebied
  • Wijze van introductie
  • Aquacultuur
  • Aangroei op scheepsrompen
  • Onderling verbonden waterwegen/bassins/zeeën
  • Impact Concurrentie
    Ecologische impact (toelichting) E. modestus competes for space and food with several native shallow-water barnacle-species. In some places worldwide it almost completely replaced the native barnacles (Lawson et al. 2004). In the Dutch littoral it competes in particular with the native barnacle Semibalanus balanoides, in the sublittoral zone with the native barnacle Balanus crenatus. In this way the species has a distinct impact on the flora and fauna living on hard substrata along the entire Dutch coast, especially in the provinces of Zeeland and the Wadden Sea (Gittenberger et al. 2010).
    Economische impact (toelichting) E. modestus is a frequent fouling species at all kinds of hard substrata, including ships’ hulls (Gollasch 2002) and in this way a nuisance to the shipping industry. It also may be one of the species fouling pipes of power plants and other facilities. Cleaning materials of fouling species may lead to high costs. On the other hand the species is used as test organism for toxicity tests: especially the larvae are very sensitive and the fact that the species produces larvae almost throughout the year is favourable for monitoring and tests (Corner et al. 1968). There are no data available on the economic impact of this species in the Netherlands.


    • Barnes, H. & M. Barnes 1968. Egg numbers, metabolic efficiency of egg production and fecundity; local and regional variations in a number of common cirripedes. Journal of Experimental Marine Biology and Ecology 2: 135-153.
    • Bishop, M.H.W. 1947. Establishment of an immigrant barnacle in British coastal waters. Nature 159: 501-502.
    • Boschma, H. 1948. Elminius modestus in The Netherlands. Nature 161: 403-404.
    • Buckeridge, J.S. & W.A. Newman 2010. A review of the subfamily Elminiinae (Cirripedia: Thoracica: Austrobalanidae), including a new genus, Protelminius nov. from the Oligocene of New Zealand. Zootaxa 2349: 39-54.
    • Corner, E.D.S., A.J. Southward & E.C. Southward 1968. Toxicity of oil-spill removers (‘detergents’) to marine life: an assessment using the intertidal barnacle Elminius modestus. Journal of the Marine Biological Association of the United Kingdom 48: 29-47.
    • Crisp, D.J. 1958. The spread of Elminius modestus Darwin in north-west Europe. Journal of the Marine Biological Association of the United Kingdom 37: 483-520.
    • Crisp, D.J. & P.A. Davies 1955. Observations in vivo on the breeding of Elminius modestus grown on glass slides. Journal of the Marine Biological Association of the United Kingdom 34: 357-380.
    • Gittenberger, A., M. Rensing, H. Stegenga & B. Hoeksema 2010. Native and non-native species of hard substrata in the Dutch Wadden Sea. Nederlandse Faunistische Mededelingen 33: 21-75.
    • Gollasch, S. 2002. The importance of ship hull fouling as a vector of species introductions into the North Sea. Biofouling 18: 105-121.
    • Harms, J. 1999. The neozoan Elminius modestus Darwin (Crustacea, Cirripedia): possible explanations for its successful invasion in European water. Helgoländer Meeresuntersuchungen 52: 337-345.
    • Lawson, J., J. Davenport & A. Whitaker 2004. Barnacle distribution in Lough Hyne Marine Nature Reserve: a new baseline and an account of invasion by the introduced Australasian species Elminius modestus Darwin. Estuarine, Coastal and Shelf Science 60: 729-735.
    • Leenhouts, P. 1948. De vondsten van Elminius modestus in Nederland. Het Zeepaard 8: 26-27.
    • Stock, J. 1949. Over het voorkomen van Elminius modestus (Darw.) op de pier van IJmuiden. Het Zeepaard 9: 22-24.
    • Stubbings, H.G. 1950. Earlier records of Elminius modestus Darwin in British waters. Nature 166: 277-278.
    • Vaas, K.F. 1975. Immigrants among the animals of the Delta-area of the SW. Netherlands. Hydrobiological Bulletin 9: 114-119.
    • Wolff, W.J. 2005. Non-indigenous marine and estuarine species in The Netherlands. Zoölogische Mededelingen 79: 1-116. [link]