Genetic detection of mislabeled fish from a certified sustainable fishery

SummaryThe decline and collapse of many of the world's fisheries has led to the implementation of social marketing that promotes the consumption of sustainably harvested seafood [1,2]. Because the success of this strategy depends on supply chain integrity, we investigated the accuracy of eco-labels for Patagonian toothfish, marketed as ‘Chilean sea bass’ (Dissostichus eleginoides), by genetically analyzing retail fish bearing certification labels from the Marine Stewardship Council (MSC). For Chilean sea bass, MSC certification labels indicate that fish were harvested from the only sustainable fishery [3,4], a population in waters surrounding the sub-Antarctic island of South Georgia and the nearby plateau at Shag Rocks [3]. We found that not all MSC-certified fish were Chilean sea bass from the certified stock: some were simply not D. eleginoides, but among those that were, we found significant genetic differences between the retail sample of fish and the certified stock population. Uncertified fish may not necessarily resemble stocks closest to their country of origin because capture and processing often occur at different places. However, significant differences between MSC-certified Chilean sea bass and the sole certified fishery for this species indicate that uncertified fish were inserted into the MSC supply chain