Something’s Fishy: Investigating Tuna Mislabelling Across the Pacific Northwest

Abstract

Seafood fraud poses a significant problem due to mislabelling having serious health, ethical, economic, and environmental implications. Despite this, it is commonly used as a method to reduce costs and to meet consumer demand. To investigate this issue in the Pacific Northwest, we tested seven unique samples of tuna, sourced from grocery stores and restaurants, for mislabelling. Three replicates each of four fresh samples (one albacore, one Atlantic bluefin, two yellowfin/ahi) and three canned samples (all skipjack) were tested using DNA extraction, PCR, and gel electrophoresis. The results were inconclusive, possibly due to a combination of factors including complications with the gel used, the small sample size, and the presence of metals and preservatives in the canned samples. We recommend future studies replicate the presented experimental design with primers specific to commonly substituted species for each tuna sample. Usage of a larger sample size would potentially result in a statistically meaningful calculation of mislabelled tuna prevalence.