RFF (Resources for the Future) has published a short review of the mislabelling of fish especially salmon and cod in the USA. The objective of the report is to provide a framework for calculating an estimate of the total amount of mislabelled fish on the market by integrating mislabelling rates with import and production data. The authors conclude there is insufficient data to be able to do this. However, the report is a useful summary of global production and consumption data for salmon and cod.
Read the full report here