We present an extensive data set of particle attenuation (cp), backscattering (bbp), and chlorophyll concentration (Chl) from a diverse set of open ocean environments. A consistent observation in the data set is the strong coherence between cp and bbp and the resulting constancy of the backscattering ratio (0.010 ± 0.002). The strong covariability between cp and bbp must be rooted in one or both of two explanations, 1) the size distribution of particles in the ocean is remarkably conserved and particle types responsible for cp and bbp covary, 2) the same particle types exert influence on both quantities. Therefore, existing relationships between cp or Chl:cp and phytoplankton biomass and physiological indices can be conceptually extended to the use of bbp. This finding lends support to use of satellite-derived Chl and bbp for investigation of phytoplankton biomass and physiology and broadens the applications of existing ocean color retrievals.