We classified global marine ecosystems using k-means clustering and cosine similarity coefficient of 21 variables, i.e.: temperature, ice cover, salinity, depth, land distance, slope, surface current, wave height, PAR, diffuse attenuation coefficient, chlorophyll a, primary productivity, nitrate, phosphate, silicate, calcite, wind speed, dissolved O2, saturated O2, utilized O2, pH. Correlations quantified relationships, and gradient analysis identified boundaries.