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New barnacle found at Alyeska terminal The nonindigenous species could have arrived via oil tanker; unclear whether crustacean is widely established in Alaska waters Wesley Loy For Petroleum News
Scientists like making new discoveries. But Greg Ruiz and his colleagues would have been content not to have found what they did recently at the Valdez oil terminal.
During a summer 2011 survey to test for evidence of invasive species in Prince William Sound, the scientists found a kind of barnacle never before seen in Alaska.
The barnacle, with the scientific name Amphibalanus improvisus, is sometimes called by the common name bay barnacle.
It is native to the Atlantic Ocean and is known to be established on the Pacific coast as far north as British Columbia.
“To our knowledge ... (this) occurrence of A. improvisus is the first record for Alaska,” said a report Ruiz and another researcher submitted to the Prince William Sound Regional Citizens’ Advisory Council.
Looking for hitchhikers The Valdez-based council is a congressionally mandated nonprofit organization that monitors the oil industry in Prince William Sound.
The council long has been concerned about potentially harmful nonindigenous species entering Alaska waters as hitchhikers on or inside tankers, which arrive regularly at the Valdez oil terminal to load Alaska North Slope crude for delivery to West Coast refineries. Alyeska Pipeline Service Co., which runs the trans-Alaska pipeline, operates the terminal.
Nonindigenous species including fish, crabs and microorganisms can travel in ballast water that’s pumped on and off ships.
Ruiz is a marine biologist with the Smithsonian Environmental Research Center at Edgewater, Md. He and Jon Geller, of the California State University system’s Moss Landing Marine Laboratories, were the principal investigators on the report submitted to the citizens’ council.
The council was to consider the report at its Sept. 20-21 board meeting in Seward.
The report notes that, to date, relatively few nonindigenous species have been detected in coastal marine waters of Alaska compared to other regions of North America.
That’s somewhat surprising for Prince William Sound, given all the tankers arriving from ports such as Long Beach, Calif., San Francisco and Washington’s Puget Sound, places where hundreds of nonindigenous species have been documented, the report said.
But the tanker arrivals began relatively recently, when the terminal opened in the late 1970s.
“There is often a lag time in detecting new invasions,” the report said, due to the time it takes for populations to grow and be discovered.
“In the case of PWS, the time has been short, and the search effort has been low,” the report said.
Only one found In a Sept. 19 interview with Petroleum News, Ruiz said the newly discovered barnacle isn’t a particularly noxious variety. It can do what barnacles do, such as foul vessel hulls or industrial water inlet pipes. Removing the crustaceans can be a costly chore.
Alaska has its own native species of barnacles, Ruiz said.
In conducting the invasive species survey, the scientists deployed PVC panels at six sites around Prince William Sound during May 2011, and retrieved them three months later. The panels worked as “passive collectors,” allowing marine invertebrates to colonize.
The six sites included the Valdez small-boat harbor, the Valdez ferry dock, the Alyeska oil terminal, the Solomon Gulch salmon hatchery, Tatitlek and Ellamar in Virgin Bay.
The researchers found only one specimen of the barnacle Amphibalanus improvisus. It was at the Alyeska terminal site. But Ruiz noted the survey covered only a small area. It’s not clear whether the barnacle is now established and self-sustaining in Prince William Sound.
“This species may have arrived on the hulls of vessels (as adults) or in the ballast water of vessels (as larvae),” the report to the citizens’ council said. “If the species becomes established, the potential impacts are not well understood at the present time.”
The carriers can be commercial or recreational vessels, Ruiz said.
The researchers hope to conduct more work to test for the presence and persistence of the barnacle.
“This is one of many species that we’ve seen moving northward into the state of Alaska,” Ruiz said.
What’s happening is species unable to reach Alaska under their own power are finding transportation to the young state, he said.
As a marine biologist, Ruiz said, discovering the new barnacle was “kind of bittersweet.”
“It’d be better if we didn’t find anything new,” he said.
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