Posted By:
Kathy Dye
Kathy Dye
Published On: July 24th, 2023

Panel to look into phenomena plaguing laak’ásk, Pyropia abbottiae

Sealaska Heritage Institute (SHI) convened an unprecedented meeting with tribes and tribal members, regional organizations and scientists from Alaska, Canada and the Lower 48 last week to delve into credible reports of variability in the health and abundance of black seaweed, a vital traditional food and cultural cornerstone for Southeast tribes.

SHI organized the meeting after lifelong Tlingit seaweed harvester Irene Dundas reported an alarming and ongoing change in black seaweed (Pyropia abbottiae or laak’ásk in Tlingit, sgíw in Haida and hla‘ashg in Tsimshian) in the Ketchikan area.

At the meeting in Juneau, Dundas said she first noticed the anomaly in 2021 while her seaweed harvest was drying in the sun at her home. The seaweed was oddly shaped and exhibited green discoloration and dimpling, she said, noting it also tasted off.

“It left a metallic flavor in your mouth and had a different scent when cooking it and a different color,” said Dundas, adding it also broke easily when dried, whereas healthy seaweed retains much of its shape.

She saw the same damage in the algae in 2022 and in 2023 while harvesting seaweed in May and June during its near three-week life cycle. Similar damage has also been reported in British Columbia and other locations, including southern Prince of Wales Island.

Keolani Booth, a tribal councilman for the Metlakatla Indian Community, is a longtime seaweed harvester for his family and community. He told the panel he had also noticed the issue.

“I have the same concerns that Irene has. Where is my way of life going? Those are some of my first memories picking seaweed on the beach with my grandparents,” said Booth, who also noted less abundance in recent years, which has curtailed his ability to share seaweed customarily and widely with the community.

“We are heartbroken as tribal leaders when we can’t provide for everyone,” Booth said. “It weighs on you heavily.”

Irene Dundas giving a presentation to a panel of scientists and Native groups at SHI on July 19, 2023, about anomalies found on black seaweed in the Ketchikan area.At the meeting, SHI heard a range of reports from scientists about seaweed, including one by Jennifer Clark, Ph.D., who studied the effects of the seaborne phenomenon known as “The Blob” on populations of Pyropia abbottiae while conducting her post-doctoral studies at the University of British Columbia. The blob was a mass of warm water that appeared in the north Pacific Ocean in 2014 and persisted into 2015. The blob was followed by an El Nino in 2015 that spanned into 2016. During that time, scientists documented a significant decrease in seaweed abundance, but the algae rebounded from 2017-2019, Clark said.

Others at the meeting also wondered if the reduced abundance of black seaweed could be caused by warmer sea temperatures during the winter, which is when black seaweed produces new seed and may not be experiencing the temperature triggers it is used to.

The green crust fouling the black seaweed is the diatom Licmophora, a single-celled algae found in marine environments. It causes the unfavorable flavor and smell and is not a new phenomenon. It has been noted by harvesters in years past, but according to Dundas, it is increasing in frequency and spread.

“It is not clear what environmental factors promote the growth of this diatom, but it can reduce the health of black seaweed by competing for light and nutrients,” noted Dr. Tiffany Stephens, Ph.D., a scientist who attended the meeting.

SHI, which was designated by the panel as the coordinator of the project, will identify tribal members and scientists to serve on a committee. The panel will develop a research design and grant proposal to establish a record of Indigenous knowledge and practices and to determine the cause and extent of the damage and whether it poses a long-term threat to seaweed populations.

“We have to develop a research program to find out what’s causing this,” said SHI President Rosita Worl, Ph.D.

Meeting attendees, from left: SHI Education Director Kristy Ford; Native Lands & Resource Director Ralph Wolfe, Tlingit & Haida; SHI Trustee Mike Miller, member of Sitka Tribe of Alaska; Professor of Chemistry and Biochemistry Mike Stekoll, Ph.D., UniversThe study could incorporate DNA research or metagenomics. That would involve collecting samples from areas of reported damage and areas where seaweed is healthy to find a potential cause, said Dr. Alida de Flamingh, a geneticist from the Center for Indigenous Science, UIUC at University of Illinois, with whom SHI has collaborated with before on DNA studies.

A DNA study, which would incorporate community insights and feedback, could determine whether the microorganisms associated with maintaining healthy seaweed are out of balance, possibly due to environmental stressors, de Flamingh told the group.

Native Lands & Resource Director Ralph Wolfe of the Central Council of the Tlingit and Haida Indian Tribes of Alaska (Tlingit & Haida) also spoke about a resolution passed by the council opposing commercial harvest of seaweed.

At the end of the session, Worl called the gathering “historic” because Native people and scientists chose to explore the issue together, integrating Indigenous knowledge and science. Tensions between Native communities and scientists worldwide exist in part because of scientists’ past disregard of Indigenous knowledge and customs.

The meeting included tribal representatives from Tlingit & Haida, Sitka Tribe of Alaska, Organized Village of Kake, Ketchikan Indian Community and Metlakatla Indian Community; Indigenous seaweed experts; representatives from Southeast Conference and scientists from the University of British Columbia, University of Alaska Fairbanks, University of Alaska Southeast, University of Illinois and Marine Agronomics. 

About Black Seaweed

"Seaweed Necklace" by Tlingit artist Chloe French from SHI’s ethnographic collection.Black seaweed has been a valuable food source for the Native people of Southeast Alaska for thousands of years. The fresh seaweed is gathered at a minus tide and dried in the sun on sheets. Some people dry it immediately, while others let it soak overnight to soften it. After it is dried, pieces are dipped into a solution of water and flavorings, such as sugar and salt, clam juice and minced clams.

When it has almost dried again, it is put through a grinder. It is stored in a variety of ways, sometimes with bits of other wild plants layered in. Subtleties in the process affect the texture and tenderness. It can be eaten dried or cooked with salmon and salmon eggs.

Seaweed offers the broadest range of minerals of any food, containing virtually all the minerals found in the ocean — the same minerals that are found in human blood. It is a food source of the B-vitamin folate and magnesium and a good source of iron, calcium and the B-vitamins riboflavin and pantothenic acid. In addition, seaweeds contain good amounts of lignans, plant compounds with cancer-protective properties.

“Black seaweed is a significant and favorite food source for our tribal members. Our Native foods contribute to our health and well-being,” said Worl. “It is widely shared by harvesters and distributed in our ceremonial activities where it serves to provide ties to the spirits of our ancestors.”

Seaweed is considered to be such an important traditional resource that it is often seen depicted in Native regalia and other pieces.

Sealaska Heritage Institute is a private nonprofit founded in 1980 to perpetuate and enhance Tlingit, Haida and Tsimshian cultures of Southeast Alaska. Its goal is to promote cultural diversity and cross-cultural understanding through public services and events. SHI also conducts social scientific and public policy research that promotes Alaska Native arts, cultures, history and education statewide. The institute is governed by a Board of Trustees and guided by a Council of Traditional Scholars, a Native Artist Committee and a Southeast Regional Language Committee.

CONTACT: Kathy Dye, SHI Communications and Publications Deputy Director, 907.321.4636,

Captions: Figures 1 and 2 — Unhealthy and healthy seaweed collected by lifelong Tlingit black seaweed harvester Irene Dundas in the Ketchikan area. Photos by Stacy Unzicker, courtesy of Sealaska Heritage Institute.

Figure 3 — Irene Dundas giving a presentation to a panel of scientists and Native groups at SHI on July 19, 2023, about anomalies found on black seaweed in the Ketchikan area. Photo by Stacy Unzicker, courtesy of Sealaska Heritage Institute.

Figure 4 — Meeting attendees, from left: SHI Education Director Kristy Ford; Native Lands & Resource Director Ralph Wolfe, Tlingit & Haida; SHI Trustee Mike Miller, member of Sitka Tribe of Alaska; Professor of Chemistry and Biochemistry Mike Stekoll, Ph.D., University of Alaska Fairbanks; Robert Venables, Southeast Conference; Professor Schery Umanzor, Ph.D., University of Alaska Fairbanks; Tiffany Stephens, Ph.D., University of Alaska Fairbanks; Tribal Councilman Keolani Booth, Metlakatla Indian Community; SHI President Rosita Worl, Ph.D.; Alida de Flamingh, Ph.D., University of Illinois; Irene Dundas, lifelong black seaweed Tlingit harvester; SHI STEAM Program Manager Arielle Halpern, Ph.D; SHI Senior Ethnologist Chuck Smythe, Ph.D.; Chief Scientist Jennifer Clark, Ph.D., Cascadia Seaweed; Tomi Marsh, Oceans Alaska board member. Not pictured (online): Research Director Lauren Bell, Ph.D., Sitka Sound Science Center; Lab Manager Shannon Cellan, Sitka Tribe of Alaska; Cyde Coil, Southeast Conference; SHI Senior Grant Writer Robi Erickson; Dolores Garza, Ph.D., University of Alaska, author and longtime Haida seaweed harvester living in Haida Gwaii, British Columbia; Executive Director Dawn Jackson, Organized Village of Kake; Juliana Leggitt, Southeast Conference; Anthropology Professor Ripan Malhi, University of Illinois; Tom Mumford, Marine Agronomics; and Anthropologist Tom Thornton, Ph.D., University of Alaska Southeast. Photo by Mircea Brown, courtesy of Sealaska Heritage Institute.

Figure 5 — “Seaweed Necklace” by the late Tlingit artist Chloe French is an example of how artists incorporate this important resource into regalia and other pieces. SHI collection.

Note: Media outlets are permitted to use these images for coverage of this story. For higher-res images, contact

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