What most concerns scientists, Chan said, is that the tunicates' reproduction cycle begins during the next two months, increasing the chances that colonies will spread. Didemnum is on the list of "100 Worst Invasive Species to Keep out of Oregon."
Between 2007 and 2009, the Washington State Department of Fish and Game spent $850,000 managing the tunicate invasion in Puget Sound, Chan pointed out.
The Winchester Bay tunicate patch was discovered earlier this year by Lorne Curran and Fritz Batson, while Curran was surveying marine life for the organization, REEF. They spotted the organisms in an area called "the triangle" an enclosed portion of the lower bay shaped like a wedge of pie. Curran photographed the tunicates, and contacted Chan, who then shared the images with tunicate expert Gretchen Lambert, and others, who confirmed the identification.
On April 26, Curran and several divers from the Oregon Coast Aquarium surveyed nearby Salmon Harbor Marina in Winchester Bay to see if the invasion had spread across the bay and to their relief, it had not. But that relief was short-lived when they returned to the triangle and found that the tunicate colonies appeared to be thriving.
"It appears that the infestation is growing rapidly," Curran said. "Where in February I saw mostly one-foot-square colonies, this time I encountered more colonies that were two-foot to three-foot square." The tunicates were found on both jetty rocks and on some of the mooring lines and "stringers" of an oyster-growing facility in the triangle.
As Chan was working with scientists, community officials and divers on the Winchester Bay discovery, he received word that a second invasion had been discovered by University of Oregon scientist Richard Emlet in the Charleston Boat Basin in Coo
|Contact: Sam Chan|
Oregon State University