Proteomics identify bowhead whale muscle tissue and baleen in cinder residues at a 16th c. Basque whaling site

Abstract

Basque whalers were active in the North Atlantic between the 11th and 18th. In the 16th and 17th c., they focused their attention to the coasts of Labrador and the Gulf of St. Lawrence, establishing shore stations from where they launched boats for chasing whales. On shore, they proceeded to render the blubber into oil by boiling it in large trypots. The residual blubber and remaining tissues were then used as fuel to boil more blubber. When the fire pit was full, the cinders were shoveled out, and the process began anew with new materials. Fist-sized lumps of cinder found at Bonne Espérance-4 (EiBk-61), a 16th Basque whaling site on the Quebec Lower North Shore, were sampled for proteomics analysis, to detect potential remains of whale tissues in the cinder. A simple protocol was employed for rapidly processing samples for nanoLC-MS/MS analysis. Out of 10 spots sampled on two lumps, materials recovered from one successfully yielded whale proteins. The study confirmed the presence of blubber and muscle remains (42 protein groups, including proteins such as myosin, myoglobin and hemoglobin) as well as baleen remains identified by cuticular keratins (12 protein groups, and up to 46 % protein coverage on type I keratin). Baleen, abundantly found at the site, was likely also used as fuel; based on keratin markers, the baleen belonged to a Balaenidae species. The processing of bowhead whale tissue was substantiated by specific peptides from myoglobin and obscurin, a result consistent with the targeting of bowhead whale by Basque whalers.