Any surface submerged in the sea will be subjected to biofouling. Within minutes macromolecules like carbohydrates and proteins will have adhered to the surface forming a basis for the following succession of settling microalgae and bacteria that will be present at the surface within hours. Within days, larvae of macroscopic invertebrates like barnacles, ascidians, tunicates and blue mussels will have colonized the surface. Within one-two weeks a full biofouling community will be present at the surface. The generalized process here described of the development of a fouling community is of course depending on the availability of larvae in the water column, temperature and sea area, but these are the steps that essentially are involved in forming biofouling.



 The bay barnacle, Balanus improvisus. B. improvisus tolerates low salinities and is therefore found in the Baltic Sea.

TMBL, place of origin IdefjordenMugga


The bay barnacle, Balanus improvisus

TMBL, prob Baltic


Nauplius larva of the bay barnacle, Balanus improvisus. The bay barnacle has six naupliar stages before it hatches into the settling stage larva, the cyprid larva. Cyprids find a suitable substrate to settle and then metamorphoses into a juvenile barnacle.

10x; Tjärnö cultures


The vase tunicate Ciona intestinalis.

Tjärnö bridge


The star ascidian Botryllus schlosseri.

2x; Kosterhavet


The blue mussel Mytilus edulis.

Mytilus edulis