Like many other groups of organisms, there are bryozoans that colonize new areas (with the unintentional help from humans) and end up on the alien species list. One of the bryozoan species that has appeared along the Norwegian coast is Schizoporella japonica, which forms orange-colored colonies that grow on various substrates.
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The species originally comes from the western part of the Pacific but has spread to both North America and Europe. In Norway, the first observations of the species were made in 2014, and it is assumed that the species has been transported here by shipping traffic since the species is usually found in harbors/marinas.
Invasive bryozoans do not necessarily create as much havoc as, for example, the carpet sea squirt (Didemnum vexillum), but they can displace naturally occurring species, encrust boats/ships and marine infrastructure.
Schizoporella is generally a rather difficult bryozoan genus, where you need to look at several different characters to be able to determine the species. The appearance of the zooid opening (orifice), the shape, location and size of the avicularia, the appearance of the brood chamber and the way the colony grows are important to note when looking at Schizoporella.
Reference:
Husa V, Agnalt A-L, Falkenhaug T, Glenner H, Jelmert A og Mortensen S (2023). Ectoprocta: Vurdering av Schizoporella japonica for Fastlands-Norge med havområder. Fremmedartslista 2023. Artsdatabanken. https://lister.artsdatabanken.no/fremmedartslista/2023/2073. Nedlastet 14.05.2025