Invasive Tunicates in Washington State
Report your sighting toWDFW: 360-902-2700
Ciona savignyi
Ciona savignyi in Hood
Canal
photo by Wayne Pallson
Ciona savignyi is a sedentary tunicate that was first observed in abundance at the Des Moines Marina in 1998 during one of the Puget Sound Expeditions. By 1999 it began to appear at the Edmonds Marina, and is now very abundant at both sites. It has also been found at the Tacoma Yacht Club. The tunicate was found in abundance during 2005 survey of geoduck beds in S. Hood Canal. It was not present during previous surveys.
Ciona savignyi on mussels
photo by Judy D Amore
Ciona savignyi is a translucent, gelatinous tunicate that gets its nourishment by siphoning water through its system, trapping food particles in a mucous net in the oral cavity. It competes with native and aquacultural species for both space and food. Because tunicates are filter feeders, they impact the food chain at the bottom, and that impact has the potential to go through the entire trophic system. There is not a lot of published information available presently regarding the invasive potential or impacts. Some research is being done on Prince Edward Island, Canada.
A team of divers with Washington Scuba Alliance and REEF, working in conjunction with WDFW, removed large quantities of Ciona savignyi at Sund Rock in Hood Canal in October 2006. Volunteer divers also regularly survey many dive sites throughout Hood Canal to check for presence of the tunicate.
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Wes
Nicholson, a local NW diver, has created a short DVD for minimal
cost that shows the project in detail, with lots of underwater footage
of Ciona. This is ideal for dive clubs to view. Please check out
his website for more information:
Earthwise Videos |
For more information on invasive tunicates, please go to the PNW Scuba website: www.pnwscuba.com/critterwatchers/invasive.htm
Report your sighting to WDFW: 360-902-2700
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