Tunicates on the Move . . .
summer marine biology investigation for middle or high school
students of Puget Sound
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?
Tunicate sightings and student
discoveries communicated to
us will be shared with others on this website.
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.
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 attached to mussel shells.