Using DNA barcoding to track seafood mislabeling in Los Angeles restaurants

Area of Science:

• Food science
• Marine biology
• Genetics

Background:

• Seafood mislabeling is a global issue, often with high reported fraud rates.
• Previous studies were limited to single-year sampling, hindering assessment of regulatory impacts.

Purpose of the Study:

• To investigate the prevalence and patterns of seafood mislabeling in Los Angeles sushi restaurants over four years (2012-2015).
• To assess if regulatory measures have impacted seafood truth-in-labeling.

Main Methods:

• DNA barcoding of the mtDNA COI gene was used to identify seafood species from 26 sushi restaurants and 16 high-end grocery stores.
• Sequenced DNA was compared against the National Center for Biotechnology Information database and U.S. Food and Drug Administration (FDA) acceptable market names.

Main Results:

• A consistent high rate of mislabeling (47%) was found in sushi restaurants across the four-year study period.
• Specific species like halibut, red snapper, yellowfin tuna, and yellowtail showed high mislabeling rates (>77%), while salmon and mackerel had lower rates (<15%).
• Mislabeling was also found in high-end grocery stores (42%), affecting red snapper, yellowfin tuna, and yellowtail.

Conclusions:

• Seafood mislabeling is persistent and widespread in sushi restaurants and grocery stores, irrespective of increased regulatory efforts and media attention.
• The study highlights the need for ongoing monitoring and enforcement to ensure accurate seafood labeling.