Comparison of EBQI with Ecological Quality Ratios (EQRs) based mainly upon P. oceanica (the organism itself) and aimed at establishing the ecological status of the seawater body.

aThe metrics of PREI are: shoot density, shoot leaf surface area, ratio between epibiota biomass and leaf biomass, depth of the lower limit and type of this limit [14].bThe metrics of POMI are: shoot density, meadow cover, percentage of plagiotropic rhizomes, shoot leaf surface area, percentage of foliar necrosis, P, N and sucrose content in rhizomes, δ15N and δ34S isotopic ratio in rhizomes, N content in epiphytes, Cu, Pb and Zn content in rhizomes [12].cThe metrics of BiPo are: shoot density, shoot leaf surface area, lower depth limit and lower limit type [15].PREI, POMI and BiPo indices are based upon distinct but similar metrics and range from 0 (lowest ecological status) to 1 (highest ecological status).