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In 2016, Peru was the fifth biggest producer of marine capture fisheries in the world, with a total production of 3.7 million tonnes. Credit: Food and Agriculture Organization of the United Nations (FAO)

Science

The cold, nutrient-rich waters of the Humboldt Current make Peru one of the most successful fisheries in the world, boasting over two thousand different fish, molluscan, and crustacean species and producing 3.7 million tonnes of fished goods in 2016 alone.

However, a new study led by researchers at Biodes Laboratorios Soluciones Integrales S.C.R.L, Universidad Nacional De Santa, and the Instituto del Mar del Peru (IMARPE) has glimpsed into the genetics of country’s seafood sector and found that many species are in fact mislabelled or substituted.

“Seafood fraud and species substitutions occur regularly in this sector and represent a global issue. Proper identification of food species is now the main concern not only for governments and companies but also for consumers due to economic, regulatory, health and religious reasons,” said Alan Marín, lead author on the study published in PLOS One.

“Conventional fish identification methods, based on morphological traits using field guides and taxonomic keys, may lead to misidentification when applied to morphologically similar or recently diverged species and can be utilized only when the full body is available. Mislabelling can happen at any point in the supply chain, from fisher to retailer; thus, determining how substitutions occur is complicated”.

Knowing this, the researchers opted to use DNA barcoding, a method that doesn’t depend on physical features being in-tact and compares the DNA of a sample to a known species database, allowing them to find an accurate match. They aimed to correctly identify fish presented in several different forms including fresh, frozen, canned, dried and cooked. A total of 35 samples (26.72 percent) were mislabelled, including tilapia labeled as wild marine fish, dolphinfish and hake labeled as grouper, and different shark species sold as “smooth-hounds”. Their results also unveiled the marketing of protected and threatened species such as whale shark, Atlantic white marlin, smooth hammerhead, shortfin Mako, and pelagic thresher sharks.

“Our results could be used as a starting point to identify the major mislabelled species and the most common substitute species, as well as high priority stages for species substitution control along the supply chain,” said Marín.

“To strengthen traceability, strict enforcement of fish inspection programs based on DNA barcoding throughout the seafood industry and retailers must be conducted by government agencies. DNA barcoding will help to prevent and combat illegal or “pirate” fishing, especially in a mega-diverse country with high fish consumption such as Peru.”

The researchers concluded by saying that developing new DNA technologies, including rapid molecular detection techniques to monitor endangered and heavily exploited species must be a priority concern.

By Ellis Moloney

Marín, A., Serna, J., Robles, C., Ramírez, B., Reyes-Flores, L., & Zelada-Mázmela, E. et al. (2018). A glimpse into the genetic diversity of the Peruvian seafood sector: Unveiling species substitution, mislabeling and trade of threatened species. PLOS ONE, 13(11), e0206596. doi: 10.1371/journal.pone.0206596

The funder (Biodes Laboratorios Soluciones Integrales S.C.R.L) provided support in the form of salaries for authors [AM, JS, CR], but did not have any additional role in the study design, data collection, and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.