The new invasive bryozoan, Bugula neritina. (Courtesy Photo | Melissa Frey, Royal B.C. Museum via University of Alaska)

The new invasive bryozoan, Bugula neritina. (Courtesy Photo | Melissa Frey, Royal B.C. Museum via University of Alaska)

Invasive invertebrate discovered near Ketchikan

‘It’s really not known’ how Bugula neritina will change the ecosystem, scientist says, but the potential for harm is real

They’re called sea lace, moss animals and Bugula neritina to scientists — and they’re not supposed to be here.

But they are here, scientists say. The invasive species has been spotted in the southern reaches of coastal Alaska, a team of researchers has discovered.

According to a study published Sept. 27 in the academic journal Bioinvasions Records, the plant-like animal has been catalogued in Ketchikan for the first time ever. Invasive species, plants and animals that may move in to a geographic area where they aren’t indigenous, can sometimes wreak havoc on local ecosystems.

University of Alaska Fairbanks professor Gary Freitag, one of the study’s authors, said they don’t yet know how the sea lace will affect marine life around Ketchikan. There’s potential that it could do nothing, or it could outcompete native species for food or territory.

“We really don’t know the impacts of this,” Freitag said.

[Invasion from ‘Borg of the ocean’ baffles scientists]

The tiny organisms attach to hard surfaces like docks, rocks and the hulls of boats, forming colonies and filter-feeding off passing food particles.

The discovery comes from a year of analysis by a scientific team from the Smithsonian Environmental Research Center, Temple University and the UAF College of Fisheries and Ocean Sciences, where Freitag works as a marine advisor for the college’s Alaska Sea Grant.

The team suspended a series of small plastic plates around Ketchikan attached to bricks, Freitag said. Floating in the water column, the plates served as hosts to a smattering of sea species. The team then lab-analyzed the diversity of animals on the plates, providing them a picture of the different animals present near Ketchikan.

The team first encountered Bugula neritina in 2015 at Ketchikan’s Bar Harbor Marina, according to the paper.

The First City is the northern-most site for the study, which looked at biodiversity in marine waters in California, Panama and Mexico. The team wanted to find out how coastal marine life differs at different latitudes, Freitag said.

“There’s been a lot of theories as to whether diversity of organisms, the amount of organisms and the number of different species, varies with latitude in a region along the coastline. They were working out whether that theory is correct,” Freitag told the Empire in a Thursday phone interview.

The researchers don’t know why or how Bugula neritina moved north to Alaska. It could have arrived on the bottom of a passing vessel. Ketchikan is the first stop for foreign-flagged cruise ships and barges and fishing boats heading north.

Warming waters may be making the migration of invasive species easier, Freitag said. Several marine species new to Alaska, like market squid, are thought to have arrived here after chasing warmer waters north. Researchers believe Ketchikan is a bellwether for such migration.

The discovery is the northernmost record of Bugula neritina in the Pacific Ocean.

“I don’t know whether there’s any real, direct evidence that climate change is causing the spread of invasive species. It’s suspected very heavily, there’s indications that it plays a role,” Freitag said.

[Squid fishery proposed for Southeast]

Alaska has fewer non-indigenous marine species than any other coastal U.S. state, the team wrote, and Ketchikan is a “key location in Alaska for early detection of marine species with the potential to spread poleward from lower latitudes.”

The paper also documents the spread of several other invasive species in Ketchikan’s marine waters. Some of them are potentially problematic for native sea life, Freitag said.

The discovery marks the culmination of years of observation not only by professionals like Freitag, but citizen scientists who’ve tracked invasive species in Ketchikan since at least 2003.

The team documented the continuing spread of three non-indigenous tunicates, invertebrates known as sea squirts. One of those species, Ciona savignyi, the Pacific transparent sea squirt, hasn’t been documented in Alaska waters since 1903.

Sea squirts can cause problems for coastal economies in ground fisheries and oyster and other mariculture farms. Freitag said they haven’t yet documented any adverse effects from the Bugula neritina or any of the sea squirt species. But the potential for disruption is there.

“It’s really not understood what the potential dangers are of any of this stuff, but it potentially has a lot of impact,” Freitag said.


• Contact reporter Kevin Gullufsen at 523-2228 and kgullufsen@juneauempire.com. Follow him on Twitter at @KevinGullufsen.


Another rare invasive species, the sea squirt Ciona savignyi. (Courtesy Photo | Melissa Frey, Royal B.C. Museum via University of Alaska)

Another rare invasive species, the sea squirt Ciona savignyi. (Courtesy Photo | Melissa Frey, Royal B.C. Museum via University of Alaska)

One of the fouling panels used in the experiment. (Courtesy Photo | Gary Freitag).

One of the fouling panels used in the experiment. (Courtesy Photo | Gary Freitag).

A crab covered in Botrylloides, found in Ketchikan. (Courtesy Photo | Gary Freitag via University of Alaska)

A crab covered in Botrylloides, found in Ketchikan. (Courtesy Photo | Gary Freitag via University of Alaska)

More in Home

Rep. Sara Hannan (right) offers an overview of this year’s legislative session to date as Rep. Andi Story and Sen. Jesse Kiehl listen during a town hall by Juneau’s delegation on Thursday evening at Juneau-Douglas High School: Yadaa.at Kalé. (Mark Sabbatini / Juneau Empire)
Multitude of education issues, budget, PFD among top areas of focus at legislative town hall

Juneau’s three Democratic lawmakers reassert support of more school funding, ensuring LGBTQ+ rights.

Allison Gornik plays the lead role of Alice during a rehearsal Saturday of Juneau Dance Theatre’s production of “Alice in Wonderland,” which will be staged at Juneau-Douglas High School: Yadaa.at Kalé for three days starting Friday. (Mark Sabbatini / Juneau Empire)
An ‘Alice in Wonderland’ that requires quick thinking on and off your feet

Ballet that Juneau Dance Theatre calls its most elaborate production ever opens Friday at JDHS.

Danielle Brubaker shops for homeschool materials at the IDEA Homeschool Curriculum Fair in Anchorage on Thursday. A court ruling struck down the part of Alaska law that allows correspondence school families to receive money for such purchases. (Claire Stremple/Alaska Beacon)
Lawmakers to wait on Alaska Supreme Court as families reel in wake of correspondence ruling

Cash allotments are ‘make or break’ for some families, others plan to limit spending.

A waterfront view of Marine Parking Garage with the windows of the Juneau Public Library visible on the top floor. “Welcome” signs in several languages greet ships on the dock pilings below. (Laurie Craig / For the Juneau Empire)
The story of the Marine Parking Garage: Saved by the library

After surviving lawsuit by Gold Rush-era persona, building is a modern landmark of art and function.

Rosemary Ahtuangaruak, mayor of the Inupiaq village of Nuiqsut, at the area where a road to the Willow project will be built in the North Slope of Alaska, March 23, 2023. The Interior Department said it will not permit construction of a 211-mile road through the park, which a mining company wanted for access to copper deposits. (Erin Schaff/The New York Times)
Biden shields millions of acres of Alaskan wilderness from drilling and mining

The Biden administration expanded federal protections across millions of acres of Alaskan… Continue reading

Caribou cross through Gates of the Arctic National Park and Preserve in their 2012 spring migration. A 211-mile industrial road that the Alaska Industrial Development and Export Authority wants to build would pass through Gates of the Arctic and other areas used by the Western Arctic Caribou Herd, one of the largest in North America. Supporters, including many Alaska political leaders, say the road would provide important economic benefits. Opponents say it would have unacceptable effects on the caribou. (Photo by Zak Richter/National Park Service)
Alaska’s U.S. senators say pending decisions on Ambler road and NPR-A are illegal

Expected decisions by Biden administration oppose mining road, support more North Slope protections.

Rep. Sarah Vance, R-Homer, speaks on the floor of the Alaska House of Representatives on Wednesday, March 13. (James Brooks/Alaska Beacon)
Alaska House members propose constitutional amendment to allow public money for private schools

After a court ruling that overturned a key part of Alaska’s education… Continue reading

Newly elected tribal leaders are sworn in during the Central Council of the Tlingit and Haida Indian Tribes of Alaska’s 89th annual Tribal Assembly on Thursday at Elizabeth Peratrovich Hall. (Photo courtesy of the Central Council of the Tlingit and Haida Indian Tribes of Alaska)
New council leaders, citizen of year, emerging leader elected at 89th Tribal Assembly

Tlingit and Haida President Chalyee Éesh Richard Peterson elected unopposed to sixth two-year term.

Most Read