The term ‘Marine trophic index’ is the CBD’s name for the mean trophic level
of fisheries landings [and one primary marine biodiversity indicator].
Trophic level measures the position of a species in a food web, starting with
‘producers’ (eg phytoplankton, plants) at level 0, and moving through primary
consumers that eat primary producers (level 1) and secondary consumers that eat
primary consumers (level 2), and so on. In marine fishes, the trophic levels
vary from two to five (top predators).
