Peptide Mass Fingerprinting (PMF): Alutiiq Kayak Project
Study of a Rare Alutiiq Warrior-Whaler Kayak
This unique single-hatch Alutiiq kayak piqued the interest of Sven Haakanson and Ronnie Lind (Alutiiq representatives from Kodiak Island, Alaska in 2003) when they were consultants to the Peabody Museum of Archaeology and Ethnology, Harvard University (Figure 1).
Figure 1. Alutiiq consultants and Peabody Museum staff in 2012 studying the Alutiiq kayak. (Left to right: Trish Capone, Alfred Naumoff, Julie Ribits, Sven Haakanson and Susan Malutin) (Copyright: Peabody Museum of Archaeology and Ethnology)
This discovery catalyzed further interest and recognition of the craft’s significance which culminated in a grant-funded project to study and conserve the Alutiiq warrior-whaler kayak, and efforts to increase its accessibility. The collaborations among the Peabody Museum, the Alutiiq Museum and Alutiiq consultants have generated a host of questions about the kayak. All aimed to understand the materials used in its construction in order to facilitate treatment decisions and contribute to developing knowledge.
Alutiiq community members, especially Alaska Native artists, are similarly interested in materials and techniques. The Alutiiq community of Kodiak, AK has been particularly interested in developing knowledge around kayaks and kayak-making, and has a multi-dimensional initiative around this effort (http://www.alutiiqmuseum.org) with the longer term goals of promoting public awareness of rich cultural traditions, inspiring youth pride, and strengthening community for a sustainable future.
The identification of materials used in ethnographic objects made from animal hides has traditionally relied on visual examination or oral tradition. These approaches, however, can be limited by sample condition, availability of reference materials, and the expertise of the researcher. The use of peptide mass fingerprinting (PMF) provides a sensitive and specific alternative to the traditional approaches. PMF uses enzymatic digestion of collagen, the major protein found in the mammalian components of the kayak as well as many other ethnographic objects, to produce a mixture of peptides which is analyzed by Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI) yielding a spectrum of characteristic marker ions—a fingerprint. This fingerprint is then compared to fingerprints from reference samples to confirm material identification. Identification is generally to the family level and, in some cases, to the species level.
In consultation with Alutiiq kayak maker (Alfred Naumoff), skin sewer (Susan Malutin) and museum director (Sven Haakanson) in 2012, two samples of stitching and six samples of skin were collected from damaged or degraded areas of the kayak (Figure 2). Through PMF the stitching was identified as humpback whale (see figure below). It is fortunate that the relatively high degree of sequence diversity in whale collagen allows specific identification of many specimens. For example, right, blue, minke, fin, gray, sei, and humpback whales can be individually differentiated among baleen whales.
Graph showing the identification of the sample from the bow stitching as humpback whale.
Based on the presence of characteristic peptide markers, the kayak skin was identified as an earless seal, a member of the phocini tribe of the Phocidae family, which includes, among others, ringed, harbor, harp, ribbon and gray seals. The Alutiiq community had thought that the skin covering might be from Steller sea lion because of its large size. However, PMF can readily distinguish sea lions (family Otariidae) from earless or true seals (family Phocidae) by the presence of a characteristic marker ion.
Figure 2. Ellen Promise sampling skin of the kayak in 2012. (Copyright: Peabody Museum of Archaeology and Ethnology)
The application of PMF to the study of the Alutiiq warrior-whaler kayak demonstrates the benefits of employing this technique in a museum laboratory, particularly where cross-disciplinary collaboration takes place. PMF has proven to be a sensitive, specific and routine method accessible to non-specialists. Our continued application of PMF to a wide range of ethnographic objects and materials will allow researchers to better understand the availability of specific materials in a given region and can serve as a tool for indigenous communities and artists to explore questions they develop regarding objects and apply the results to initiatives within their communities.
The Alaska Native kayak research at the Peabody Museum was partially supported through a grant from the Save America’s Treasures program administered by the U.S. Institute for Museum and Library Services.
In 2013, grant funding to further this analytical work was received from the National Park Service’s National Center for Preservation of Technology and Training. For further information, please go to: http://projects.iq.harvard.edu/pmfcm/