What you'll find at this site:

Some Background . . .

Some Activities . . .

For teachers and parents. . .


Tunicates, including exotic tunicate, Ciona savignyi

Exotic Tunicates on the Move . . .

a summer marine biology investigation for middle or high school students of Puget Sound


Introduced species are attracting lots of attention in the media these days. Marine invaders of our coastlines are especially troubling, because they are nearly impossibly to eradicate once they become established. Many scientists are working hard to keep up with the rate that invasive species are now showing up on our shores. They are trying to answer questions such as:

    • What new species have appeared in our area?
    • How extensively they have established themselves?
    • What impacts they are having on native species whose habitats they have invaded?


Students in the Puget Sound region have a chance to witness and help document the invasion of a newly arrived marine organism that attaches to docks and boat hulls. How it will affect the marine environment will take some time to assess, but one thing is clear already. This species should be easy to spot as it moves into new parts of Puget Sound, and it may in fact become a dominant organism in parts of its new environment.

 The invader is Ciona savignyi (pronounced Sióna savíni), a tunicate, an interesting invertebrate animal closely related to vertebrates like ourselves. Although Puget Sound is home to many native tunicate species, this one is native to Japan. Ciona savignyi was probably brought into Puget Sound by trans-oceanic shipping, perhaps in ballast water carried inside ships, or as adult animals attached to ships' hulls.


 Ciona savignyi on mussel shells

Ciona savignyi attached to mussel shells.

Tunicate sightings and student discoveries communicated to us will be shared with others on this website.

 What is a Tunicate?

  Experiments with Marine Settlers

Catalog of Dock Fouling Species

Invasive Marine Species