Marine Trophic Index (MTI) measures the health of a country's fishing stock based on expected catch and changes over time. The MTI measures the degree to which a country is depleting species at higher trophic levels and “fishing down the food web.” The variable is log-transformed according to the formula ln(x+α), where α = 9.51E-07.

Original source: Sea Around Us.

When using this variable, please cite both EPI and the original source.